Undergraduate Research

Poster presentation in Biotechnology        Chairs: Prof. S.L. Huang/Prof. M.H. Kwon/Prof. K.H. Lin

No.

Topic

Presenter

B1

DETECTION OF Edwardsiella ictaluri ON CATFISH (Pangasianodon hypophthalmus) BY NESTED PCR

The study aims to develop a timely and accurate qualitative method to detect Edwardsiella ictaluri – a bacteria that causes bacillary necrosis disease on striped catfish by Nested PCR, which replaces traditional methods. Two designed specific primer pairs, EI-T3N for Edwardsiella genus and EI-T3SS for E. ictaluri species, were experimented on the in vitro and in vivo conditions to evaluate their amplification and specificity capabilities. Furthermore, the results of this research can also be utilized to conduct optimization experiments on the components and processes involved in the Nested PCR reaction for the development of a qualitative kit for detecting the bacterial pathogen E. ictaluri.

X.M. Nguyen, Q.T. Nguyen, T.G.H. Le, D.C. Pham

B2

Multiplex PCR for detection of S. agalactiae on cultured Nile tilapia (O. niloticus)

Streptococcus agalactiae (Group B Streptococcus) is a contributing factor causing hemorrhagic eye edema in fish, particularly Nile tilapia (Oreochromis niloticus). In this study, four specific primer pairs, consisting of two reference pairs from previous research (amplifying sip gene and cpsE gene), along with two newly designed primer pairs (targeting lytA and scpA gene). The multiplex PCR method was used to detect pathogenic S. agalactiae both in vitro and in vivo settings. The results demonstrated that the Multiplex PCR successfully detected bacteria in the infected fish samples utilizing the four mentioned primer pairs. The presence of bands at 227 bp, 385 bp, 596 bp, and 931 bp corresponded to the lytA gene, cpsE gene, sip gene, and scpA gene, respectively.

H.K.N Truong, D.V. Nguyen, N.P.K. Luu, D.C. Pham

B3

Production of Genomic DNA Extraction Kit for Gram-positive Bacteria

In this work, a research kit was developed to successfully remove the peptidoglycan coating prevalent in gram-positive bacterial cell envelopes and increase genomic DNA recovery. The kit uses a silica matrix for DNA extraction. The first phase was investigating the effect of three parameters on gDNA recovery from Gram-positive bacteria: bacterial density, Lysozyme concentration, and incubation duration. The Box-Behnken design experiment yielded the highest gDNA concentration (195.241 µg/mL) at 1 mg/mL lysozyme concentration for 10 minutes, with a bacterial density of 6x10^8 cells. The results indicated that the experimental gDNA concentration was equal to both the model prediction and the reference value from the commercial extraction kit. In addition, the research kit remains stable even after six months of room temperature storage. As thus, it concluded that the kit was successfully created and passed the production assessment requirements.

Q.T. Pham, S.T. Nguyen, T.A.T.Tran, D.C. Pham

B4

Evaluation of phytochemicals and antioxidant activities of S. androgynus (L.) Merr. leaf extracts and its application in candy products

Sauropus androgynus (L.) Merr is a botanical remedy employed to boost the lactation in both nursing mothers and lactating mammals due to its rich sterol content. Ethanol and aqueous extracts of Sauropus androgynus leaves (SAL) was evaluated the antioxidant and phytochemical properties in order to investigate their bioactivity. The extracts were variant in their phytochemical contents depending on different solvents, including the highest content of polyphenols in SAL aqueous extract (93.48 ± 4.7 mg GAE/g) but the ethanol extract exhibited better flavonoid content (308.8 ± 27.6 mg QE/g). The antioxidant properties of these SAL extracts demonstrated the better activity in aqueous extract using both ABTS+ method and FRAP method with IC50 values of 148.466 ± 0.107 μg/mL and 10.73 ± 0.0006 μg/mL, respectively. This study was also the first preliminary surveys to evaluate the possible application in candy production combined with ginger root extract, resulting the best ratio of SAL extract: ginger extract: water is 2:1:2. Thus, androgynus leaf extracts possess significant bioactivity and development potential in candy production. 

T.L. Le, T.M.T. Nguyen, G.T. Huynh, T.T. Doan

B5

Antioxidant, phytochemical, and skincare properties of C. quephongensis leaves

Ethanol extract of Camellia Quephongensis (CQ) leaves was analyzed to investigated its antioxidant and phytochemical properties. The presence of bioactivity compounds has been investigated in the study, including polyphenols (261.79 ± 3.71 mg GAE/g extract), flavonoids (389.63 ± 4.24 mg QE/g extract), tannin (178.33 ± 2.60 mg CE/g extract), and saponin (486.50 ± 4.93 mg OAE/g extract). The antioxidant activity of CQ extract was IC50 value of 6.27 ± 0.10 μg/mL in ABTS+ method and 23.57 ± 1.37 μg/mL in FRAP method. Its anti-inflammatory activity with an IC50 = 15.23 ± 0.28 μg/mL was superior to diclofenac (IC50 = 58.03 ± 5.74 μg/mL) but inferior to pednisolone (IC50 = 10.42 ± 0.23 μg/mL). Application of the CQ extract into skincare gel exhibited the moisturizing gel's ability to protect the skin from the impact of UVb rays through evaluating the SPF index of the product at extract concentrations of 0%, 1%, 2%, 3%, 4% is 0.89 ± 0.02, 1.81 ± 0.06, 5.89 ± 0.08, 8.79 ± 0.11 and 11.72 ± 0.16, respectively. In conclusion, the CQ leaf extract had high phytochemical properties and potential applications in cosmetics. 

T.T. Phan, N.H.T. Nguyen, T.B.H Pham, T.T. Doan

B6

Effects of elicitors on the biomass production of Vetiver grass (C. zizanioides) and application in mitigating lead contamination

Vetiveria zizanioides is a species of plant in the Poaceae family, known as a hyperaccumulator plant due to its massive root system to absorb pollution and ability to survive in adverse environmental conditions. The purpose of this research is to investigate the potential vetiver grass to absorb lead pollution in soil. By adding Indole-3-acetic acid (IAA), Salicylic acid (SA), and Humic acid (HA) with different concentrations and observing monitoring indicators such as number of roots, length of roots, biomass, etc. On day 30 after treatments, the SA treatments showed better growth in both fresh biomass of roots and stems, especially in the SA3 (210 mg/L) treatment (32.67 ± 2.52 g and 81.67 ± 2.08 g, respectively). However, there was a significant difference in root length, and was best recorded in the experiment using IAA2 (2 mg/L). Besides, the research presented effective results in mitigating lead contamination of vetiver grass after using plant elicitors. It brings the prospect of application in treating soil pollution in polluted areas, helping to regenerate nature. 

M.C. Pham, V.Q. Nguyen, H.V. Huynh, H.L.T. Truong, T.T. Doan

B7

Recycled fish pond sediment as biofertilizer for Basella alba L. cultivation

This study aims to research on salvage the mud from catfish-aquaculturing process in Mekong Delta, subsequent to mingle with microbial treated brown coals, straws and coffee grounds for microbial organic fertilizer (MOF) production. In composting stage, the ingredients proportion demonstrated as 5:2:1:1 (sediment : coffee grounds : brown coals : straws) with 0.4 m3 in scale and following by effective assessment on Malabar spinach (Basella alba L.). The experimental result witnessed an efficient quality of MOF in those are 0.19 % of immediately available (IA) potassium, 0.27 % of IA phosphorium, 0.633 % of total nitrogen, 6.74 % of organic carbon. Both heavy meatal content and E. coli density are approved in allowable threshold. There are 3 manuring formulas as following: formula 1 (F1) contains 100 % chemical fertilizer of NPK 16:16:8, formula 2 (F2) contains 50 % organic fertilizer and 50 % of chemical fertilizer, formula 3 (F3) contains 100 % of MOF. The result based on plant height, fresh weight, the number of leaves and buds. The fresh weight of Malabar vegetables which fertilized with F3 was higher than that of F1 and F2. The F2 crops were taller than F1 and F3 by 4.70 cm and 9.67 cm, respectively. The F2 leaves and buds were more quantity than F1 and F3 by 4.12 leaves and 1.00 bud than by 7.00 leaves and 2.00 buds, respectively. Consequently, the research above has the ability to reduce sediment elimination and gradually supersede chemical substances in crop cultivation and ameliorate vegetable yield by considered MOF formulas.

M.K.T. Ho, D.K. Nguyen, K.L.H. Pham, M.T. Nguyen, N.L.T. Pham, H.T.T. Nguyen

B8

Isolation, screening, and identification of thermophilic ligno-cellulolytic fungi from agricultural soil in VN

Fungi are known as the most efficient microorganisms which are able to turn agricultural waste into biofertilizer by producing cell wall- degrading enzymes. Composting involves thermophilic microbes which degrade lignocellulose. This study isolated and investigated thermophilic lignocellulolytic fungi on degradation of corn cobs. A total of nine thermophilic fungal strains were isolated and determined cellulolytic activity using carboxymethylcellulose (CMC) medium. Among them, strains M2, M3, and M5 showed high clearance zones around colonies with diameters of 4.56, 4.67, and 5.67 mm, respectively. M5 exhibited the strongest cellulolytic degradation with reducing sugar concentration in CMC broth media was 486.67 mg/L.  In addition, strains M2, M3 and M5 is capable of lignin degradation with a halo zone on tannic acid medium of 3.33, 2.00, and 1.89 mm, respectively. Furthermore, M5 exhibited the strongest ability to corn cob degradation with the reducing sugar concentration of 55.67 mg/g after 8 weeks incubation. Hence, strain M5 was selected as potential bioinoculant for lignocellulose degradation of agro-wastes. Based on conidia morphological characterization and ITS gene sequencing analysis, strain M5 was identified as Penicillium citrinum.

T.M.T. Tran, M.T. Nguyen, H.T.T. Nguyen

B9

Isolation, screening, and identification of antagonistic bacteria from soil against F. oxysporum

Fusarium oxysporum is the causal agent of wilt in tomatoes, which is one of the most destructive fungal diseases. This fungal disease strain is an important mycotoxin producer that causes several negative effects on human health. Bacteria, which are found in various natural environments including the rhizosphere and soil displayed fungicidal activity against fungal phytopathogens. In our study, we investigated the antifungal activity of isolated bacteria which inhibited the growth of the plant pathogen Fusarium oxysporum causing wilt disease in tomatoes. In total of 48 isolated bacterial strains, 9 strains showed antifungal activity against Fusarium oxysporum using co-culture method. Two bacterial strains T1-4 and T10-1 exhibited strong antagonistic activity against fungal pathogens with control values of 50.8 and 48.6%, respectively. Moreover, the volatile organic compounds (VOCs)c of these two strains also inhibited the mycelial growth of F. oxysporum. In the 96-well plate assay, the culture filtrate of T1-4 showed the strongest antifungal activity with a minimum inhibitory concentration (MIC) of 1.25%. Based on 16S rRNA gene sequence analysis, T1-4 was identified as Bacillus velezensis.

M.T.T. Huynh, H.C. Le, and H.T.T. Nguyen

B10

Surfactin extract of B. subtilis to evaluate the ability to inhibit the growth and development of E. coli

In recent years, microbially-derived surface-active compounds have attracted attention due to their biodegradability, low toxicity, environmental compatibility, and ability to be produced from renewable and cost-effective substrates. Among the various classes of biosurfactants, lipopeptides are of great interest because of their high surface activities and therapeutic potential. Surfactin is one of the most efficient biosurfactant known so far, belonging to the lipopeptide family produced by Bacillus subtilis spp. B. subtilis strain CN5 was previously isolated from soil samples in Bau Nuoc Soi hot spring, Dong Nai Province, Vietnam and used for surfactin production. Optimized media for surfactin production was at 9% glucose in combination with 5% Ammonium chloride. Environmental growth parameters like temperature (37°C) and pH value of 7 enhanced surfactin yield. Further studies are needed to optimize the fermentation parameters to improve the rate and yield of surfactin production by B. subtilis strain CN5.

D. K. Trinh, T.K. Phuong, M.D. Nguyen, N.T. Nguyen

B11

Optimization Of Culture Conditions For Biosurfactant Production From P. aeruginosa

Microbiologically-derived  surfactants  or  biosurfactants are becoming an important alternative to chemical surfactants in almost every sector in the modern industry because of their improved properties compared to their chemical counterparts. In  this study,  we  have  tried  to  optimize  culture  conditions  for maximum  biosurfactant production from  Pseudomonas  aeruginosa VK30 that was previously isolated from soil sample in Ho Chi Minh City, Vietnam. Based on the emulsification index measurement (E24), optimized media for biosurfactant production was at 3% olive oil in combination with 0.1% NH4NO3. Biosurfactant obtained from strain VK30 will need to further investigate to understand their applications in different areas like bioremediation of polluted environment, pharmaceutical sector, food industry, cosmetics industry etc.

T.U.N. Truong, T.P.N. Tran, T.T.M. Do, N.T. Nguyen

B12

Characterization of B. amyloliquefaciens CN12 and its biocontrol potential on softening coco peat

Coco peat as agricultural waste sorbent commonly utilized as a growing medium, which improve water retention and enhance aeration. However, in its raw form, cocopeat has been reported to contain phytotoxic elements which inhibit plant growth. Astringent substances such as tannin and lignin in coco peat, these compounds harm the roots and inhibit growth of plant. Normally, untreated coco peat has a lignin content of about 70% and tannin content of about 8%, so the electro-conductivity index (EC) will normally have a value of > 3 mS/cm, and the lignin content accounts for about 30 %, normal pH value is at 5.5 - 6.5. A high EC value threshold will contain many salt ions, which will be very limited for most plants with poor salt tolerance, such as kale and fruit trees such as durian and mangosteen. To overcome this situation, we have discovered that the bacteria Bacillus amyloliquefaciens CN12 (B. amyloliquefaciens CN12) decomposed tannin, lignin, and cellulose in coco peat as well as decreased the EC value to threshold < 1.0 mS/cm. In this study, we successfully produced probiotic powder preparation B. amyloliquefaciens ≥ 108 CFU g-1 and decreased the EC value down to 0.83 ± 0.13 mS/cm after 28 days of treatment. Moreover, B. amyloliquefaciens produced significantly Indole-3-acetic acid (IAA) which may be involved in plant growth promotion. Along with that, the mixture of processed coco peat with soil and fertilizer improves seedling quality and growth of the tomato plant.

N.H. Phan, T.H.D. Ngo, T.X.Q. Nguyen, B.N. Hoang, T.N.L. Vien, N.T. Nguyen, M.T. Pham

B13

Characterization of the probiotic B. subtilis SNZ 1972 encapsulated with whey protein plus glucose

The research delves into the impact of encapsulating the probiotic Bacillus subtilis with whey protein and glucose on various health parameters. The main objective was to create a B. subtilis preparation by freeze-drying a combination of whey protein and maltodextrin, followed by an assessment of its probiotic properties. The study focused on evaluating of preparation B. subtilis's survival rate post-drying, its ability to withstand bile salts and stomach acid, and its defense mechanisms against harmful microbes. Findings revealed a significant cell density of 11.90 ± 1.87 (x108 CFU/mL) in the dried product, with a commendable cell survival rate of 73.72% ± 4.95. Preparation B. subtilis exhibited versatility in various conditions, thriving in pH 2 and pH 3 environments and displaying robust survival rates in environments containing bile salts. After 3 h of incubation in a 0.3% bile salt environment - a bile salt concentration thought to be significant for screening probiotic strains - the cell density at this concentration reached 27.50 ± 0.90 (x108 CFU/mL), translating to a 93.87% ± 2.95 survival rate. The comparable survival rate was 14.32% ± 0.97 with the greatest bile salt content in the digestive tract at 2%, which corresponds to a cell density of 4.20 ± 0.36 (x108 CFU/mL). Additionally, the preparation showcased resilience against harmful microorganisms such as Salmonella typhimurium, Pseudomonas aeruginosa, and Escherichia coli.

P.T.U. Nguyen, K.L. Ma, N.T. Ta, T.H.X. Vo, T.D. Tran, M.T. Pham

B14

Polysaccharides extracted from G. salicornia for A. cinnamomea solid cultivation to obtain saponins

This study investigates the effect of polysaccharides extracted from Gracilaria salicornia as a substrate for solid cultivation of Antrodia cinnamomea to amplify saponin extraction. G. salicornia, a red seaweed, was valued for its polysaccharide and agar content. The optimal polysaccharide extraction conditions were HCl 0,1 N with a ratio of liquid to solid of 1:50 (v/w), at 100 oC for 3 hours. Currently, A. cinnamomea was a medicinal fungus native to Taiwan, recognized for its bioactive saponins with diverse pharmacological benefits. The factors affecting saponin biosynthesis were investigated, the results were 20.00 g/L polysaccharide extract from G. salicornia, 10.00 g/L rice bran powder and 4.00 g/L CaSO4 gives the highest saponin content. Total saponin extracts from A. cinnamomea showed quite high anti-inflammatory capacity at 400 PPM (10.318 ± 0.521%) was evaluated using a heat-induced bovine serum albumin (BSA) denaturation assay and also showed moderate antibacterial activity was tested by agar well diffusion method. Inhibition zones of saponin extract against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus strains were 19.67 ± 0.58, 13.00 ± 0.00, 20.50 ± 0.87 mm, respectively at 500 mg/mL. This research contributes to understanding the potential of marine polysaccharides and agar for sustainable production of saponin extract, with implications for pharmaceutical and nutraceutical industries.

T.T. Vuong, T.T. Nguyen, K. Sawetkamon, T.T.V. Nguyen, T.N. Tran

B15

Study on Antioxidant and Antibacterial Activity of Total Polyphenol Extract from Pomegranate Peel (P. granatum L.) Combined with Peptide from L. acidophilus

The aim of this study determined the antibacterial activity when combining pomegranate peel extract (PPE) and peptide from Lactobacillus acidophilus bacteria (LAB). The obtained extracts were characterized in terms of total phenolic compounds (TPC) and antioxidant activity (AA), determined by the DPPH radical scavenging activity and expressed as IC50 (half maximum inhibitory concentration). The extracts obtained pomegranate peel extract had a statistically higher overall bioactive potential (TPC: 198.64  0.09 mg GAE/mg extract; IC50: 7.386  0.022 mg/mL). Pomegranate peel extract (PPE) combined with LAB peptide was evaluated their antibacterial activity by the agar diffusion method. The results showed that this combination had high antibacterial activity at a ratio of 1:1 with sterile ring diameters of 19.70  0.17 mm for Staphylococcus aureus and 21.17  0.29 mm for Escherichia coli. This research suggests that the combination of pomegranate peel extract and LAB peptide from L. acidophilus may be a useful approach to the control of harmful bacteria towards application in food technology.

A.T. Tran, T.D. Nguyen, N.H. Duong, N.T. Vo, T.N. Tran

B16

Extraction of polysaccharides from seaweed (S. henslowianum) for R. toruloides G17 cultivation to obtain carotenoids and bioactivity assay

Carotenoids are natural pigments found in plants and microorganisms. Astaxanthin, a red-orange carotenoid, has potential in biomanufacturing. The yeast Rhodosporidium toruloides was grown in Sargassum henslowianum seaweed broth to produce astaxanthin. The study investigated the most effective conditions for extracting polysaccharides from seaweed using 0.1 N HCl solvent for 3 hours at a temperature of 100°C with a sample:solvent ratio of 1:100 (w/v). The optimal conditions for astaxanthin biosynthesis in seaweed broth were 10 g/L polysaccharide from seaweed broth and 10 g/L NH4NO3. The astaxanthin content achieved was 1138.6 μg/L. Astaxathin obtained from the yeast Rhodosporidium toruloides in seaweed broth provides high antioxidant activity. By the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the IC50 value of 7.903 µg/mL of astaxanthin from the optimal medium has 1.76 times better antioxidant activity than vitamin C (IC50 = 13.91 µg/mL) and the inhibition zones of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa strains were 12.10 ± 0.14, 13.10 ± 0.14, 11.45 ± 0.07 and 11.98 ± 0.04 mm, respectively, at the astaxanthin concentration of 1500 µg/mL.

N.T. Le, H.T. Nguyen, T.N. Tran

B17

Impact of chitosan, seaweed extract, and dried guava leaf extract for the production of biofilm-forming solution to preserve sapodilla

This study evaluates the effectiveness of the biofilm-forming solution produced from chitosan, seaweed extract (SE), and dried guava leaf extract (GLE) on sapodilla's physicochemical properties and storage time. SE was extracted from seaweed by the 0.1 N HCl solution extraction method and had the highest polysaccharide content and antioxidant ability. The total polyphenol content of SE was 4.812 ± 0.187 mg GAE/g. The highest values of GLE extraction efficiency and antioxidant activity were obtained at a solid-liquid ratio of 1:5 with 60% ethanol solvent.  The total polyphenol content of GLE was 17.702 ± 0.401 mg GAE/g.  The biofilm-forming solution combined from chitosan, SE, and GLE with the concentrations 0.5, 1.0, 1.5, and  2% was sprayed on sapodilla to create a surface coating and was stored at 5 C for 20 days. It was found that the application of 2% GLE showed that the sapodilla retains its best properties over a long period of storage. Shrinkage and rotting were the lowest for the sapodilla compared to the control samples. The 2% concentration of CLE can also well control the density of yeast and mold on the surface of the sapodilla. Therefore, it is concluded that chitosan, SE, and GLE 2% can be applied as bio-preservatives to extend the shelf life of the fruits without compromising their quality.

C.D. Le, H.K.V. Vo, T.Q.M. Luong, T.C.V. Nguyen

B18

Optimization of the enzymatic- and ultrasound-assisted extraction of hydrolyzed collagen from basa fish (P. bocourti) by RSM

This study aimed to optimize hydrolyzed-collagen extraction from basa skin fish (Pangasius bocourti) by Alcalase using Response Surface Methodology (RSM). First, fish skin is treated with 0.05 N NaOH, w/v ratio = 1/10, for 2 hours to remove non-collagen protein, then continue to treat with 1% H2O2, ratio w/v = 1/10, for 2 hours to depigment the fish skin and finally treat with 10% n-butanol, w/v ratio = 1/10 for 24 hours to remove fat. Collagen extraction was performed with pH 7 buffer, w/v ratio = 1/10 for 24 hours, the extract was precipitated with collagen with 2.5 M NaCl for 24 hours. Collagen is obtained in pieces and is white. The results showed that the hydrolyzed collagen with the Alcalase enzyme concentration of 0.15% stabilized in buffer pH 7 at 4 C in 24 hours was 41.27% in recovery yield. After that, sample analysis experiments were conducted to test the specific properties of type 1. The product collagen has the following specifications: 12.42% moisture, 0.24% lipid, 0.18% ash, and maximum solubility at pH 2 – 4. The specification meets the basic requirements of collagen additives used in cosmetics, pharmaceutics, and foods.

T.Q.M. Luong, C.D. Le, T.C.V. Nguyen

B19

Isolation and screening of strains capable of producing surfactants

Biosurfactants produced from microorganisms are receiving much attention due to their outstanding properties and high stability compared to chemical surfactants. The aim of this study is to isolate and identify bacterial strain from samples with the capacity to produce. By using water samples in Ho Chi Ming city, seventeen strains were screened out using the combination of oil spreading and emulsification index (E24) test. In which, strain S4-3 showed the highest ability to produce surfactants. Optimized media for surfactant production was at 0.5% glycerol in combination with 0.1% NH4NO3. Environmental growth parameters like temperature (37°C) and pH value of 7 enhanced surfactant yield. Using the morphological and 16S rRNA, the strain was identified as Burkholderia vietnamiensis. Interstingly, it is the first time strain belonged to species vietnamiensis reported the ability for surfactant production. Therefore, this strain might be useful as an alternative to chemical surfactants for a wide range of potential applications.

T.T.L. Nguyen, M.H. Tran, T.T.V. Nguyen, N.T. Nguyen

B20

Antioxidant, enzyme inhibitory and antibacterial activities of sub-fraction extracts from C. operculatus (ROXB.) MERR. ET perry leaves

The bioactivity of sub-fraction extracts obtained from the n-hexane fraction of Cleistocalyx operculatus (Roxb.) Merr. et Perry leaves was investigated for antioxidant and antibacterial activities. The results showed the presence of the compound β-Sitosterol in the sub-fraction H3. The best antioxidant activity of the substances yielded an IC50 = 26.746 ± 0.593 μg/mL according to the ABTS+ method, while the DPPH method showed the best result with an IC50 = 370.497 ± 5.93 μg/mL. The compound β-Sitosterol exhibited enzyme inhibitory activity with an IC50 value of 39.634 ± 0.285 µg/mL for α-amylase inhibition and an IC50 value of 33.183 ± 0.056 µg/mL for α-glucosidase inhibition. The antibacterial activity was evaluated using the MIC method, with β-Sitosterol showing MIC values ≤ 125 µM/mL against both Salmonella sp. and Klebsiella pneumoniae. In conclusion, the sub-fraction hexan extracts of Cleistocalyx operculatus (Roxb.) Merr. et Perry leaves exhibit high bioactivity and potential for application in medicinal research.

T.T. Doan and T.H.T. Pham

B21

Beneficial effects of polysaccharide extract from H. erinaceus on the recovery of gut microbiome after chronic exposure to antibiotics.

Hericium erinaceus, has been known under the name Lion’s mane mushroom, is a familiar herbal medicine marketing in Vietnam. Hericium erinaceus extracts is reported to have protective effects on several gastrointestinal diseases. The previous study by La Thi Mai Hanh from Faculty of Applied Science, Ton Duc Thang university indicated that polysaccharide extracts from Hericium erinaceus potentiated the growth of Lactobacillus acidophilus which is regarded as important probiotics in the intestine. In this study, we investigated the effects of polysaccharide extracts from Hericium erinaceus on the recovery of gut microbiome after chronic exposure to antibiotics. Chronic exporsure to antibiotics induced abnormal changes in Gram (+)/Gram (-) ratio in mouse fecal samples. In addition, chronic exposure to antibiotics caused detrimental effects on the weigh gain in mouse model. Treated with polysaccharide extracts from Hericium erinaceus attenuated antibiotics-induced abnormal in Gram (+)/Gram (-) ratio and decrease in weight gain. Our results suggests that polysaccharide extracts from Hericium erinaceus can be potential supplementary for patient who have GI problem after chronic exposure to antibiotics.

Q.D. Trinh, N.M. Nguyen, P.V. Nguyen, N.H.B. Duong, H.N. Mai, D.T. Pham

B22

Developing rapid and affordable histochemical tests for assessing the browning potential of 'Hass' avocado fruit

Avocados are fast becoming one of Australia's indispensable fruits, with 67% of Australian households choosing to buy avocados. However, the stress imposed on the fruit by the rigours of the post-harvest supply chain and the inherent potential for browning of the avocado fruit pulp may lead consumers to reduce their purchases. To address these issues, we aimed to develop a rapid and affordable histochemical test for assessing the browning potential of avocados on-farm and at regular intervals during the supply chain. A methodology, originally developed for detecting browning potential in peaches, was adapted from Kader and Chordas (1984) for determining the browning potential of avocado. To optimize the methodology the first objective was to compare and evaluate three different histochemical tests in selected fruit (apple, persimmon, banana and avocado) for its efficacy in detecting phenolic compounds. The tests included the ferric chloride (FeCl3) tannin print test, the polyphenol oxidase activity (PPO) test and the phenolic compounds test. In a second objective, the most effective application technique of the reagents to the fruit was investigated by comparing the effects of dripping the histochemical solutions directly on fruit, or by soaking the filter paper in the reagents first and then applying either the wet or then dried filter paper to the fruit. After refining the histochemical methodologies, we used the detection techniques of browning potential for avocado as describe in Golan et al. (1977) for untreated avocado fruit to validate the feasibility of using the above-mentioned histochemical tests. Browning potential changes with increasing fruit maturity was evaluated for avocado on days 0, 1, 3 and 5 of shelf life where fruit was held at 20℃ and 90% relative humidity. Data collection included a visual flesh colour rating (0-5) and recorded colour values (L, a*, b*) for browning potential test (0-180 min), PPO test (0-2 min) and phenolic compounds test (0-2 min), the at two-time intervals as indicated. The results showed that the improved histochemical test can be used to detect the browning potential of avocados. However, it is not sensitive enough to analyse the correlation between maturity and browning potential. 

Pratibha Bishnoi

Poster presentation in Chemical Engineering    Chairs: Prof. F.M. Wang/Dr. T. K. Pham/Dr. T. Loi Nguyen

No.

Topic

Presenter

C1

Development of hybrid, B. amyloliquefaciens coated fertilizers from sludge wastes for food crops with maximum 120 days to maturity

Hybrid fertilizer pellets with various NPK contents were made from organic-rich sludge wastes including biogas sludge and catfish pond sediment and synthetic NPK precursors. A thin layer of Bacillus amyloliquefaciens bacteria, which were screened and isolated from Bau Nuoc Soi hot spring in Dong Nai Province, was coated on the pellet surface. The hybrid fertilizer pellets were applied in various food crops with maximum 120 days to maturity, including Brassica vegetables (Yu Choy greens, mustard greens, white cabbage) and grain crop (rice), in pot tests and in field tests. Yields and growth rates of the vegetables and rice achieved during growth cycles up to 120 days were competitive with those achieved from the same dose of the commercial fertilizer application. It has been found that soils with the 1-year application of the Bacillus amyloliquefaciens coated fertilizers not only contained a balance of available nutrients but also enriched with P- and K- solubilized microorganisms. It has been found that simultaneous application of the organic-synthetic nutrients in pellet form with the assistance of Bacillus amyloliquefaciens maintained crop yields and improved nitrogen use efficiency in comparison to the traditional application of the organic nutrients before cultivation and the synthetic nutrients during cultivation.

T.T.S. Tran, H.T. Nguyen, L.D. Nguyen, T. N. Le-Luong, N. K. Nguyen, A.T. Nguyen-Le, N.T. Nguyen, N.X.Q. Vo, N.X.P. Vo

C2

Recovering maximum values out of wastes in planted microbial fuel cell systems for environment resilience and energy security

Various integrated systems of a microbial fuel cell and (i) an up-flow constructed wetland with emergent grass species (Cenchrus setaceus or Nelumbo nucifera), (ii) a floating wetland with submerged, floating leaved species (Trapa natans L.) or free-floating species (Vetiveria zizanioides L.) were implemented. Biomass (e.g. stems, roots, fruits, flowers) of the macrophytes were either collected as nutritious foods or converted to value-added products including biochar and essential oil. For comparative yield of food crops, low-strength surface water was used in the integrated systems, in which essential NPK nutrients were added via home-made slow-released hybrid fertilizer pellets for plant uptake. For high value-added biochar and essential oil, real domestic wastewater was circulated through the integrated systems for 30-day evaluation. Highest removal of TSS (98.4%), BOD5 (90.9%), COD (76.7%), TP (85.9%), and NH4–N (89.7%) from the wastewater was seen after an 8-day HRT. Average power outputs for these planted microbial fuel cells varied from 49 to 72 kW ha-1 year-1, in which ca. half of the power outputs was generated from plant photosynthetic extrudates.  

V.K. Le, T.H.T. Dang, N.P. Nguyen, T.T.N. Le, K.H. Phan, T.A.M. Huynh, N.X.Q. Vo, V.T. Doan, N.X.P. Vo

C3

Effect of Silica Nanoparticle Additives on the Mechanical Properties of Silicone Rubber-Based Magnetorheological Elastomers Under Magnetic Fields

Magnetorheological elastomer (MRE) is an emerging smart material composed of magnetic fillers and elastic matrix. Under the influence of a magnetic field, the stiffness and modulus of this rubber-based polymer containing magnetic particles can be varied, enabling the tuning of the mechanical properties. To improve the performance of MRE, researchers have focused on improving the surface compatibility of the raw materials. In previous studies, silica has been introduced into the MRE multiphase system as a coating material and additive to enhance the thermal stability and mechanical properties. However, the effect of silica additives on the mechanical behavior of MREs under magnetic fields has not been fully explored. In this study, a series of silicone rubber-based MREs containing various contents of silica nanoparticles were prepared using 30 vol% Fe-Si-Cr powder as the magnetic filler and silicone rubber as the elastic matrix. The microstructure and mechanical properties of the MREs were characterized using digital microscopy and a universal testing machine. In addition, the tensile properties of the MREs were investigated with a universal testing machine in the presence and absence of magnetic fields. The experimental results demonstrate that silica nanoparticles improved the interfacial interaction between the magnetic filler and the matrix, thereby influencing the performance of the MREs. Compared to the MREs without an applied magnetic field, the tensile properties of the silicone rubber-based MREs were significantly improved under the influence of magnetic fields. These findings reveal the potential of MREs for applications in the smart device and engineering fields, providing new ideas for further development. 

Yun Xue, YiHe Zhang, Kwang Ho Yu, Eun-Sang Lee, and Chul-Hee Lee

C4

Optimization of essential oil extraction from C. cassia L. bark and application in the synthesis of cinnamyl alcohol and dicinnamylidene acetone

Cinnamaldehyde is the natural compound which is primarily found in cinnamon essential oil. It can be transformed into various other compounds such as cinnamyl alcohol, cinnamyl acid, azomethines, benzaldehyde, cinnamylidene compounds, and oxime ethers. In this study, cinnamon oil was extracted from the bark of Cinnamomum cassia L. by using hydro-distillation. Three-factor Box-Behnken Design was used to optimize the extraction condition, including solid-to-liquid ratio (L/S ratio), soaking time and concentration of NaCl solution. It was found that the maximum yield of essential oil was obtained at soaking time of 7 days in a 24% NaCl solution and liquid–solid ratio of 1:12. Under optimized condition, essential oil was achieved a yield of 1.5% relative to the absolute dry weight. Chemical composition of the essential oil was determined via gas chromatography–mass spectrometry (GC-MS), revealing that the oil contained cinnamaldehyde of 58%. The obtained cinnamon oil has been successfully converted into cinnamyl alcohol and dicinnamylidene acetone.

A.N.D. Quach, A.D.H. Pham, C.B.Tran

C5

Development of triple-hybrid bioscaffold based on Vietnamese cocoon origin silk fibroin, chitosan and nano biphasic calcium phosphates for enhancing alveolar bone regeneration

Alveolar ridge atrophy and post-extraction bleeding represent prevalent complications following a tooth extraction, particularly in instances where patients do not promptly receive suitable interventions. Recently, bioscaffold, a type of biomedical material, have shown great potential for treating such conditions and surpass conventional bone grafting methodologies in terms of efficacy and therapeutic outcomes. Specifically, bioscaffold constructed from polymer materials are becoming necessary in clinic due to their good mechanical properties, high biocompatibility, and controllable biodegradability, which enables the ability to regenerate bone tissue defects. However, combining these materials can be challenging due to the complexity and cost of the synthesis process. Therefore, this research aims to propose a facile and sustainable method to formulate a triple-hybrid bioscaffold based on Vietnamese cocoon origin silk Fibroin, chitosan, and nano-biphasic calcium phosphates (nano-BCP), which have high porosity (55-80%) and suitable swelling capacity to facilitate cell proliferation and nutrient diffusion. Additionally, the compressive strength of the bioscaffold can be tuned in the range of 50 - 200 kPa by changing the amount of nano-BCP addition. Importantly, to support the treatment of symptoms after tooth extraction and promote the regeneration of alveolar bone at the defect site, the scaffold is enhanced with dual therapeutic agents, including methylprednisolone, an effective anti-inflammatory drug, and salmon calcitonin, a pro-osteogenesis factor. Furthermore, the biosafety of the scaffold was demonstrated through direct contacting experiment on the chorioallantoic membrane of chicken embryos as well as hemocompatibility and hemostasis tests, making it a promising platform for multifaceted pharmaceutical delivery and alveolar bone defect remediation.

T.H.H. Tran, M.A.L. Hoang, Q.P.L. Huynh, D.K. Nguyen, K.Q. Nguyen, G.V.H. Phan

C6

Preparation of antimicrobial dressing from Vietnamese cocoon/chitosan/nanoclay containing pro-angiogenic factor for promoting diabetic ulcer healing

Wound healing is a complicated process influenced by several internal and external elements within the body. In particular, to manage hemostasis and prevent wound infection, advanced dressings are required for diabetic foot ulcers (DFU), a common but dangerous condition that frequently affects individuals with diabetes. Furthermore, the current healthcare industry has established objectives and hypotheses for transforming conventional gauze bandages - which have numerous drawbacks - into advanced, bioactive dressings. In this study, a foam dressing with antimicrobial, hemostatic and pro-angiogenic properties was created specifically for DFU, integrating the advantages of several natural polymers with modern wound care technologies. This dressing is not only highly biocompatible but also incredibly effective at healing wounds because it uses chitosan (CS) for its hemostatic and biocompatibility properties, Vietnamese cocoon derived silk fibroin (SF) for its mechanical strength, and montmorillonite (MMT), a natural nanoclay, for its unique physicochemical properties of high reinforcement, extreme water absorption, and controlled drug delivery. In addition, this treatment has broad-spectrum antibacterial activity against both gram-positive and gram-negative bacteria due to its ciprofloxacin (CIP) releasing capacity. Moreover, an in ovo investigation utilizing the chick embryo chorioallantoic membrane assay indicated erythropoietin (EPO) as a potentially effective agent for vascularization, hence accelerate the wound healing process. This research has demonstrated that the silk fibroin/chitosan/nanoclay based dressing, in conjunction with two additional medications, CIP and EPO, effectively promoting hemostasis and wound tissue regeneration. 

H.P. Nguyen, D.N. Nguyen, Q.N.D. Nguyen, N.T. Huynh, N.Q.T. Nguyen, G.V.H. Phan

C7

Ionically cross-linked core-shell hydrogel bead based on silica nanoparticles/chitosan/pectin for oral delivery of calcitonin

Protein and peptide based therapeutics are being widely used in medicine, because of their outstanding benefits compared with traditional small molecules drugs, such as great specificity and effectiveness, high safety and good tolerance. Currently, almost proteins and peptides are being administered  by the parenteral routes to avoid degradation in the gastrointestinal tract, especially in the harsh acidic condition of stomach. Meanwhile, the oral administration commonly exhibits higher compliance and convenience. Salmon calcitonin (sCT), a peptide drug, is prescribing in clinic as main therapy for osteoporosis and Paget's disease through a frequent injection. In this study, a novel nanoengineered hydrogel bead was prepared for the oral delivery of sCT. Firstly, the sCT was embedded and adsorbed into the mesoporous silica nanoparticles (MSNs), and then the sCT/MSNs complex was encapsulated in the core of a core-shell structured hydrogel bead composed of chitosan core and pectin shell. The physicochemical properties of the synthesized MSNs and bead were characterized using BET technique, transmission electron microscopy, and scanning electron microscopy. The bead showed high biocompatibility through a chick embryo chorioallantoic membrane assay. Importantly, in vitro release study of sCT under simulated gastrointestinal tract (GIT) conditions demonstrate the effective protection of sCT within the core-shell structure at pH 1.2 and sCT release mostly at the simulated intestinal fluid (pH 6.8) in a sustained manner.  

C.N.D. Tran, H.P.H. Nguyen, Q.K. Pham, L.H. Ngo, K.Q. Nguyen, G.V.H. Phan

C8

Natural Compounds Inhibit Influenza Virus Neuraminidase N1 in silico Studies

Influenza A viruses have become a global concern, prompting extensive efforts to discover neuraminidase inhibitors for prevention. This study utilized a machine learning model to assess the binding affinity of compounds from the MedChemExpress (MCE) database to neuraminidase. Confirmation of ligand-binding affinity was achieved through detailed atomistic simulations, including molecular docking and molecular dynamics simulations. Additionally, the study provided valuable insights into the physical mechanisms underlying the binding process of ligands to neuraminidase. The results highlighted five promising compounds micronomicin, didesmethyl cariprazine, argatroban, Kgp-IN-1, and AY 9944 as potential inhibitors of neuraminidase N1 in the influenza A virus. Furthermore, the analysis identified ten key residues Glu119, Asp151, Arg152, Gln228, Glu277, Glu278, Arg293, Asn295, Asn344, and Tyr402 that likely play crucial roles in regulating the ligand-binding process to N1.

Q.M. Thai, T.H. Nguyen, H.T.T. Phung, M.Q. Pham, P.N.K. Tuyen, J.T. Horng, S.T. Ngo

C9

Preparation and characterization of ZnO nanocomposites on nanocellulose-based materialss

Lichens are formed from symbiosis between fungi and algae. They are known as a source of biologically active compounds with a wide range of properties, including antibacterial, antifungal, antioxidant, antivirus, anticancer. Recent studies have revealed that lichens also contain compounds with potential for treating type 2 diabetes by inhibiting alpha-glucosidase activity in vitro.  Furthermore, research suggests that cultivated lichen fungi produce numerous novel compounds with largely unexplored biological activities. Salazinic acid, isolated from the lichen Parmotrema indicum, along with its synthesized derivatives, demonstrates promising activity against type 2 diabetes. Notably, all derivatives exhibited stronger alpha-glucosidase inhibitory activity compared to the positive control acarbose (IC50 332 μM), with IC50 values below 50 μM. Additionally, the study employed molecular docking simulations to further understand how these compounds interact with alpha-glucosidase.

T.D.H. To, H.T. Tran, K.C.H. Dinh, T.A.N. Nguyen

C10

Fabrication of an AZO thermal insulation coating on glass

Nanocomposite materials, produced using polymers, have gained global attention in recent years due to their extensive use in scientific disciplines such as materials science, technology, and engineering. This study conducted acid hydrolysis to manufacture cellulose nanocrystals (CNC) from microcrystalline cellulose (MCC). The nanocellulose produced was utilized as the primary polymer for synthesizing zinc oxide nanoparticles (ZnO) using an in situ solution technique. Through experimental analysis, the composition, characteristics, and ability to initiate photocatalysis of CNC, ZnO, and ZnO/CNC were examined. Using advanced analytical techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR), we conducted a comparative study on the ability of three materials - ZnO, CNC, and ZnO/CNC - to degrade Methylene blue (MB) under visible and UV light conditions. The findings demonstrated that the ZnO/CNC exhibited consistent photocatalytic performance, achieving a remarkable 91% degradation efficiency of MB under UV light for a duration of 5 hours.

H.T. Tran, T.D.H. To, K.C.H. Dinh, T.A.N. Nguyen

C11

Alpha-glucosidase Inhibitory Activities of Salazinic acid Derivatives from Parmotrema lichen

Currently, climate change stands as the most significant challenge confronting the Earth. Human activity, particularly the emission of gases from industrial operations, is a primary contributor to the greenhouse effect. It results in a rise in the environmental average temperature. It is crucial to do research on glass with AZO coating, which is based on ZnO metal oxide compounds doped with Al3+, in order to reduce the temperature behind the glass. The co-precipitation process employing Polyethylene glycol compound as a surfactant produces the most ideal insulation material. The reaction involved the dissolution of zinc nitrate salt (Zn(NO3)2.6H2O) and aluminum nitrate salt (Al(NO3)3.9H2O) in a solution containing ethanol and PEG-1000. The reaction took place at a temperature of 75 oC for a duration of 30 minutes. The mixture was subsequently adjusted to a pH range of 7-8 by the NH3 solution diluted in alcohol, and at 75 oC for a duration of two hours. Afterwards, vacuum filtration was applied to get precipitate with an opaque white hue. The precipitate underwent a drying procedure at a temperature of 80 oC for 12 hours until it became completely free of moisture. The resulting solid was then subjected to calcination in a furnace at a temperature of 600 oC for a period of 2 hours, resulting in the formation of AZO powder. Subsequently, AZO was dispersed in methyl ethyl ketone. Ultimately, acrylic resin was introduced to produce a uniform mixture that coated the glass. The thermal insulation of the glass was subsequently evaluated, and the observed results indicated a temperature decrease of 8 oC. The UV resistance was also assessed to verify the efficacy of the glass coating in preventing UV radiation.

T.H. Do, T.M.D. Tran

C12

Photocatalytic removal of methylene blue dye using hydrogel-based MgO@ZnO nanocomposite

Water pollution is one of the most urgent global challenges today. Photocatalysis has emerged as a highly effective method for eliminating persistent contaminants in water due to its efficiency, energy savings, low cost, environmental friendliness, and absence of secondary pollution. Additionally, photocatalysts are not consumed in the process, making them sustainable. Photocatalytic materials are the core of photocatalytic technology. However, despite their effectiveness, a significant challenge remains the difficulty in recovering and reusing current photocatalysts, which limits their practical application. This study explores the feasibility of reusing modified ZnO with MgO (MgO@ZnO) photocatalysts by integrating them into various hydrogel matrices, including agar and alginate. The research focused on evaluating the potential of these hydrogel matrices to immobilize photocatalysts, thereby enhancing their stability and recyclability compare to MgO@ZnO without hydrogel matrix. Key parameters such as catalyst amount, hydrogel morphological structure, and environmental conditions were systematically controlled to optimize their performance. The effectiveness of different hydrogel preparations was then studied and compared. XRD, SEM, EDX, FTIR, TEM were carried out to evaluate the characteritics of synthesized materials. The MgO@ZnO nanocomposite was suscessfully synthesized with an average diamiter of 69 nm. The incorporation of MgO@ZnO into hydrogel-based matrices demonstrated significant adsorption and photocatalytic abilities when tested with the dye Methylene Blue (MB). The highest photocatalytic performance after 180 minutes achieved up to 95.19% removal of MB when using Alginate/MgO@ZnO, compared to 89.85 % with Agar/MgO@ZnO and 86.55% wirh MgO@ZnO. Additionally, the reusability of the Alginate/MgO@ZnO and Agar/MgO@ZnO photocatalysts was promising, with efficiency remaining as high as 74.85% and 47%, respecctively, after five cycles of recovery and reuse. This indicates that the hydrogel matrices effectively enhance the durability and recyclability of the photocatalysts. The findings suggest that incorporating MgO@ZnO photocatalysts into hydrogels can provide a sustainable and efficient solution for wastewater treatment and pollutant degradation. This research underscores the potential of using hydrogel matrices to immobilize and reuse photocatalysts, offering significant advancements in green catalytic technology.

H.N. Nguyen, T.N. Tang, P.U.L. Vo, M.N.N. Thi, Q.H. Nguyen

C13

Preparation of Injectable composite hydrogel based on alginate/HA orientation for bone tissue engineering

The injectable hydrogel-biodegradation alginate and nano-hydroxyapatite (HA) are dual-integrated together in the 3D network structure of the hydrogel by the release of calcium cations contained in CaCO3 by the presence of glucose-d-lactone (GDL). The concentration of Ca2+:GDL (1:2) is fixed to stabilize the pH in the range of 6.8-7.2. Furthermore, a series of studies have been performed such as gelation time, swelling behavior, degradation, injectability and shape moldability, and hemolysis assays. In gelation time values are always guaranteed to be below 500s to preserve gelation when injected into the body. The loading of HA into the material affects some of the properties of the hydrogel, swelling behavior gives the value after loading HA decreased by 11% in 24 hours while the total mass content in degradation decreased by 9% when loaded HA. Finally, hemolysis assays give reliable results when no signs of blood clotting occur during the experiment. The hemolysis ratio (%) is always below 2.6%, which is a value that can be controlled when the material is injected into the body.

T.T.B. Tran, Q.K. Nguyen, and H.K. Tran

C14

Preparation antibacterial PVA/CS electrospun nanofiber membrane for face mask

Amid mounting concerns regarding fine and ultrafine particulate matter, disposable surgical masks have become widely adopted as a key protective measure. This surge in usage is particularly driven by the onset of the SARS-CoV-2 pandemic and the escalating levels of urban air pollution. Nevertheless, the non-biodegradable composition of these masks poses significant environmental risks, as discarded masks contribute to pollution. To address this pressing issue, this study focuses on creating biodegradable nanofibers through the electrospinning process, utilizing polyvinyl alcohol (PVA) and chitosan (CS) as alternatives to conventional polymers found in commercial surgical masks (CSM). The resulting PVA/CS nanofiber mats displayed impressive characteristics, including an average fiber diameter of 0.14 ± 0.05 µm and a pore diameter of 0.20 ± 0.08 µm. These mats, with a thickness of 20 µm, exhibited exceptional filtration efficiency, effectively removing PM2.5 fine dust by 99.6667% with a pressure drop of 186 Pa. Additionally, they demonstrated water resistance and antibacterial properties against both gram-negative and gram-positive bacteria. The successful production of PVA/CS electrospun membranes highlights their potential as sustainable alternatives to non-biodegradable polymers in surgical masks. This research underscores the critical importance of environmentally friendly solutions in combating pollution while ensuring public health safety.

V.T. Ngo, T.P.V. Nguyen, H.H. Nguyen, N.H. Vu, Q.K. Nguyen, H.K. Tran

C15

Synthesis Zeolitic imidazolate framework-8 and its application for removal Cr(VI) in aqueous solution

Synthesis Zeolitic imidazolate framework-8 and its application for removal Cr(VI) in aqueous solution

Hexavalent chromium (Cr(VI)) is well-known as a toxic pollutant discharged by chemical industries. Therefore, developing advanced materials to remove Cr(VI) efficiently is thus of great significance in environmental sciences. In this research, the zinc-based zeolitic imidazolate framework material (ZIF-8) has been synthesized by ultrasonic method - a more accessible synthesis approach for Cr(VI) ions removal in aqueous solutions. The as-synthesized ZIF-8 adsorbent was characterized by different methodologies, such as XRD, SEM, BET, and UV-Vis spectra. Difference factors affecting removal percentage are experimentally investigated, including synthesis methods, pH of solution, and initial concentration of Cr(VI) to achieve the optimal condition removal. The obtained results indicate that ZIF-8 material has nanoparticle size (100 nm) with highly crystalized, uniform morphology, and large surface area (1717 m2/g) that effectively adsorbs 80% of the 20 ppm Cr(VI) aqueous solution and maintains 60% recycle capacity after five times.

H.H. Khong, D.H. Nguyen, G.C.L. Huynh, V.H. Huynh, T.N. Tran, T.B.T. Truong

C16

Synthesis of TiO₂.SiO₂/Agar composite material and investigation of the possibility of dye wastewater treatment

Dye wastewater treatment poses significant challenges due to the synthetic nature and complex aromatic structures of dyes. Advanced Oxidation Processes (AOPs) utilizing photocatalysts have emerged as promising solutions for this issue. This research focuses on the synthesis of nano TiO2@SiO2/agar composite materials for dye wastewater treatment, aiming to reduce costs and time. The study investigates the synthesis of nano silicon dioxide (SiO2) from rice husk. It evaluates the degradation activity of dye substances using photocatalysts embedded in TiO2.SiO2/agar composites. The experimental methods include precipitation and sol-gel processes, while the analytical methods encompass Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Ultraviolet-Visible Spectroscopy (UV-Vis), and Energy Dispersive X-ray Spectroscopy (EDX). Nano SiO2 particles were successfully synthesized from rice husk. The study achieved the synthesis of TiO2.SiO2/agar photocatalytic material, which demonstrated an excellent treatment efficiency (95.9%) compared to TiO2/agar (89.2%). The agar-based facilitated the recovery and reuse of the material, maintaining high efficiency in cycles. Results showed a 96% degradation efficiency of methylene blue (MB) after 4 hours, with a reuse efficiency of 86.5-85.1%.

M.H. Le, T.T.L. Nguyen, T.M. Nguyen, V.M. Ngo, Q.H. Nguyen

C17

Carbon-coated electrode materials from biomass for lithium-ion batteries

Carbon-coated electrode materials from biomass for lithium-ion batteries

Cellulose crystals were extracted from sugarcane bagasse through hydrolysis, and a hydrothermal method was employed to synthesize carbon-coated Fe2O3 compounds (Fe2O3@CM). The carbon coating is designed to enhance the stability of the material when used as electrodes in lithium-ion batteries. Analysis using Energy Dispersive X-ray Spectroscopy (EDS) and Scanning Electron Microscopy (SEM) revealed that the Fe2O3@CM product possesses a uniform core-shell structure with an average size of 1 - 2.5 µm. The study demonstrated that carbon derived from sugarcane bagasse can be utilized to create carbon-based materials for anode electrodes in lithium-ion batteries, improving the properties of electrode materials and advancing the development of cutting-edge materials for energy storage systems. Electrochemical analysis indicated that the highest capacity in the first cycle reached approximately 1000 mA.h.g-1 and remained stable at 400 mA.h.g-1 after 200 cycles. The carbon coating on Fe2O3 significantly enhanced capacity stability compared to pure α-Fe2O3 when used in anode electrodes for lithium-ion batteries.

T.S. Chung, Q.H. Nguyen, T.H.N Thi, Q.H. Nguyen

C18

Treatment of high strength ammonium wastewater in a two-stage vertical flow microbial fuel cell-constructed wetland

This study aims to improve the treatment efficiency of high strength ammonium wastewaters in the two-stage vertical flow MFC-CW unit. Raw domestic wastewater was diluted and modified with acetate before being fed with a downflow-upflow regime in batch mode. The results show that high nitrogen removal efficiency of CW-MFC planting Vertiveria Zizanioides L. was achieved. N-NH4+ removal efficiencies were 64.1  2.5% after the first day and 86.2  2.0% after four days with the influent N-NH4+ concentration of 80 mg/L and COD of 600 mg.L-1 at the hydraulic loading rate (HLR) of 0.2 m3.h-1.m-3. COD removal efficiencies were 87.6  2.4% after the first day and 97.9  1.2% after four days with the power density of 83.1  17.0 mW.m-3. The twofold increase of HLR could further improve the treatment capacity and bioelectricity generation (89.5  0.7% of N-NH4+ removal, 99.1  0.4% of COD removal after four days and 162.3  81.0 mW.m-3 of bioelectric recovery). Effluent N-NH4+ concentrations satisfied the discharge limit of N-NH4+ concentrations (< 5 mg.L-1) for industrial wastewater in Vietnam (QCVN 40:2011/BTNMT). The results have elucidated the ability of the two-stage MFC-CWs to produce electrical power while simultaneously treating high strength ammonium wastewater.

N.X.P. Vo, T.V. Doan, T.P.O. Tran, N.X.Q. Vo

C19

Emergence of Scrub Typhus in Asia-Pacific Countries due to climate changes

Climate change significantly impacts the distribution, prevalence, and severity of vector-borne diseases (VBDs), including scrub typhus, which is transmitted by trombiculid mite larvae (chiggers). Rising temperatures and shifting precipitation patterns expand the habitats favorable for chiggers, potentially leading to epidemics in areas with little immunity or awareness, thus increasing morbidity and mortality rates. Additionally, extreme weather events like flooding and heavy rain can boost mite populations, prolong their lifecycle, and increase their density, thereby raising human exposure risks. Furthermore, climate change affects migration patterns and human behavior, bringing people into closer contact with vector habitats and heightening disease transmission risks. These changes alter vector habitats, increase human exposure, and complicate disease management, exacerbating the spread of scrub typhus. This paper addresses these challenges and emphasizes the necessity of a multi-faceted approach to mitigate this growing public health threat. Key strategies include environmental management to reduce vector habitats, enhanced disease surveillance to detect and respond to outbreaks promptly, and community education to raise awareness about preventive measures. By adopting such comprehensive measures, it is possible to reduce the impact of climate change on the spread of scrub typhus and protect vulnerable populations from this emerging threat.

Pragya Sharma

C20

Nanotechnology Governance in India: Current Status and Future Directions

The outlook on "Nano-materials, products, medicine, and technology" currently lacks a universally accepted definition among regulatory bodies worldwide. Engineered nanoparticles and formulated products containing nanomaterials are not yet subject to precise regulations regarding their production, handling, and labelling. Despite their immense potential in treatment and diagnosis, nanomedicines still face significant concerns about safety and toxicity that often go unnoticed. Consequently, a regulatory framework with specific guidelines for nanotechnology products is being developed to maximize the benefits of nanomedicines for humanity. Regulatory bodies such as the United States Environmental Protection Agency (EPA), the US Food and Drug Administration (USFDA), and the Health and Consumer Protection Directorate of the European Commission (EC) have been proactive in addressing the risks associated with nanomedicines. This study aims to illustrate the current status and propose future perspectives of nanomedicine by compiling guidance from various regulatory bodies, thereby clarifying the regulatory landscape of nanotechnology. However, ambiguity persists regarding the regulation and safety of nanomaterials. Therefore, harmonizing assessment practices for nanomaterials with a unanimous opinion is essential. On a global level, the OECD and its Working Party are currently addressing issues related to manufacture nanomaterials.

Vivek Mandot

Undergraduate Research 2016

In the school year of 2015-2016, the undergraduate research projects "Study on bioethanol production from Chaetomorpha sp" registered by the students of the Faculty of Applied Science- Dinh Anh Hoa group getting the third prize of Ton Duc Thang University Research Awards.