Coconut (Cocos nucifera L.) or 'the tree of life' is one of the most important palm crops due to its versatility. Reduction in coconut productivity due to natural calamity and disease threats has raised the urgent need to develop in vitro techniques that can overcome the obstacles of the traditional breeding method. Embryo culture is one of the earliest in vitro culture techniques applied to practical problems and so far has proved itself to be of great value to breeders. However, contamination is one of the most serious problems that reduces the efficiency in in vitro culture techniques. Thus, appropriate surface sterilization treatments are highly important to in vitro culture establishment. The present study was performed to evaluate the sterilization effect of calcium hypochlorite by comparing with sodium hypochlorite. This study also examined the effects of calcium hypochlorite concentrations on plantlets morphogenesis. The findings revealed that amongst the tested treatments, 0.5% (w/v) calcium hypochlorite was the most effective treatment with the lowest rate of contamination. This treatment also significantly improved shoot and root elongation in comparison with calcium hypochlorite at higher concentrations (3% and 6%, w/v). Thus, this concentration was found to be optimal for surface sterilization of two coconut cultivars - Aromatic and Xiem Red Dwarf. Besides that, the results obtained from this study indicated that 70% (v/v) ethanol was not critical in surface sterilization protocol of coconut embryo culture. This research has provided an improved approach for surface sterilization which was previously dependent on sodium hypochlorite and ethanol.
{"title":"Effect of calcium hypochlorite on surface sterilization and seedling growth of Vietnamese coconut varieties","authors":"Tran Phuong Quynh, Hoang Thi Lan Xuan, Tran Ai My, Nguyen Thi Thanh Thao, Nguyen Thi Phuong Thao, Nguyen Thien Quang","doi":"10.15625/1811-4989/16221","DOIUrl":"https://doi.org/10.15625/1811-4989/16221","url":null,"abstract":"Coconut (Cocos nucifera L.) or 'the tree of life' is one of the most important palm crops due to its versatility. Reduction in coconut productivity due to natural calamity and disease threats has raised the urgent need to develop in vitro techniques that can overcome the obstacles of the traditional breeding method. Embryo culture is one of the earliest in vitro culture techniques applied to practical problems and so far has proved itself to be of great value to breeders. However, contamination is one of the most serious problems that reduces the efficiency in in vitro culture techniques. Thus, appropriate surface sterilization treatments are highly important to in vitro culture establishment. The present study was performed to evaluate the sterilization effect of calcium hypochlorite by comparing with sodium hypochlorite. This study also examined the effects of calcium hypochlorite concentrations on plantlets morphogenesis. The findings revealed that amongst the tested treatments, 0.5% (w/v) calcium hypochlorite was the most effective treatment with the lowest rate of contamination. This treatment also significantly improved shoot and root elongation in comparison with calcium hypochlorite at higher concentrations (3% and 6%, w/v). Thus, this concentration was found to be optimal for surface sterilization of two coconut cultivars - Aromatic and Xiem Red Dwarf. Besides that, the results obtained from this study indicated that 70% (v/v) ethanol was not critical in surface sterilization protocol of coconut embryo culture. This research has provided an improved approach for surface sterilization which was previously dependent on sodium hypochlorite and ethanol.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87429167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/16934
Ngoc Hoa Binh Nguyen, Thi Thuy Phuong Pham, T. Huynh, T. Nguyen, Thi Thu Hoai Nguyen
Scanning electron microscope (SEM) is a popular tool used for observing bacteria surface and morphology. Using Pseudomonas aeruginosa as a model, this work aimed to show a SEM preparative procedure that is simple and economical but does not result in considerable data loss. This was accomplished via testing fixing ability of 10% formalin versus 2.5% glutaraldehyde, efficiency of air drying versus t-butyl alcohol drying method. Following that, polypropylene, dialysis tubing and agar were also assessed for their ability to serve as a supporting material for cell adhesion in preparing sample for SEM. Consequently, obtained data showed that the procedure using 24-hour 10% formalin fixation and t-butyl alcohol drying preserved well bacterial morphology. With this procedure, little cell or membrane damage was seen while extracellular structures were clearly observed. Furthermore, when this procedure was applied with different types of substrates including polypropylene, dialysis tubing, and agar, it showed that sample fixed on polypropylene maintained well extracellular structures meanwhile sample fixed on agar presented well bacterial morphology. In conclusion, our data suggested that coating samples on polypropylene, followed by 24-hour 10% formalin fixation and t-butyl alcohol drying was appropriate for observing bacteria under SEM.
{"title":"Sample preparative procedure for Pseudomonas aeruginosa observation under scanning electron microscope","authors":"Ngoc Hoa Binh Nguyen, Thi Thuy Phuong Pham, T. Huynh, T. Nguyen, Thi Thu Hoai Nguyen","doi":"10.15625/1811-4989/16934","DOIUrl":"https://doi.org/10.15625/1811-4989/16934","url":null,"abstract":"Scanning electron microscope (SEM) is a popular tool used for observing bacteria surface and morphology. Using Pseudomonas aeruginosa as a model, this work aimed to show a SEM preparative procedure that is simple and economical but does not result in considerable data loss. This was accomplished via testing fixing ability of 10% formalin versus 2.5% glutaraldehyde, efficiency of air drying versus t-butyl alcohol drying method. Following that, polypropylene, dialysis tubing and agar were also assessed for their ability to serve as a supporting material for cell adhesion in preparing sample for SEM. Consequently, obtained data showed that the procedure using 24-hour 10% formalin fixation and t-butyl alcohol drying preserved well bacterial morphology. With this procedure, little cell or membrane damage was seen while extracellular structures were clearly observed. Furthermore, when this procedure was applied with different types of substrates including polypropylene, dialysis tubing, and agar, it showed that sample fixed on polypropylene maintained well extracellular structures meanwhile sample fixed on agar presented well bacterial morphology. In conclusion, our data suggested that coating samples on polypropylene, followed by 24-hour 10% formalin fixation and t-butyl alcohol drying was appropriate for observing bacteria under SEM.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86251885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/16659
Nguyen Van Ngoc, Nong Van Duy, Nguyen Thi Minh Phuong, Hoàng Thị Bình
DNA barcoding is a tool for species discrimination and identification which helps overcome the problem of identification that cannot be covered by morphological identification. Quercus is the second biggest genus of Fagaceae in Vietnam as well as Lam Dong province after Lithocarpus. However, the species discrimination study of the Quercus species in Vietnam and Lam Dong province has yet to be well uncovered due to ambiguous species boundaries and the lack of universal molecular markers. In this study, the DNA barcodes were tested to discriminate among the species of the Quercus genus in Lam Dong province. A total of sixteen and two samples of the Quercus and Lithocarpus genus (out-group) were tested using matK, rbcL, and internal transcribed spacer (ITS). Of which, the new sequences in this study were sequenced from six species and one unknown species of Quercus, the rest was retrieved from GenBank. The BLAST, neighbor-joining, and Bayesian methods were employed to examine species discrimination success. The results showed that ITS was an efficient single-locus barcode for Quercus species by yielding the highest rate of universality as well as the best discriminatory and authentication power among the barcodes examined. In addition, the combination of ITS+matK+rbcL achieved the highest species discrimination. Therefore, matK and rbcL should not be used as DNA barcodes for the species identification of Quercus, whereas the combination of three genes that were proposed in this study is the most suitable DNA barcode for identifying Quercus species in Lam Dong province.
{"title":"Evaluation of DNA barcodes in discriminating Quercus species from Lam Dong, Vietnam","authors":"Nguyen Van Ngoc, Nong Van Duy, Nguyen Thi Minh Phuong, Hoàng Thị Bình","doi":"10.15625/1811-4989/16659","DOIUrl":"https://doi.org/10.15625/1811-4989/16659","url":null,"abstract":"DNA barcoding is a tool for species discrimination and identification which helps overcome the problem of identification that cannot be covered by morphological identification. Quercus is the second biggest genus of Fagaceae in Vietnam as well as Lam Dong province after Lithocarpus. However, the species discrimination study of the Quercus species in Vietnam and Lam Dong province has yet to be well uncovered due to ambiguous species boundaries and the lack of universal molecular markers. In this study, the DNA barcodes were tested to discriminate among the species of the Quercus genus in Lam Dong province. A total of sixteen and two samples of the Quercus and Lithocarpus genus (out-group) were tested using matK, rbcL, and internal transcribed spacer (ITS). Of which, the new sequences in this study were sequenced from six species and one unknown species of Quercus, the rest was retrieved from GenBank. The BLAST, neighbor-joining, and Bayesian methods were employed to examine species discrimination success. The results showed that ITS was an efficient single-locus barcode for Quercus species by yielding the highest rate of universality as well as the best discriminatory and authentication power among the barcodes examined. In addition, the combination of ITS+matK+rbcL achieved the highest species discrimination. Therefore, matK and rbcL should not be used as DNA barcodes for the species identification of Quercus, whereas the combination of three genes that were proposed in this study is the most suitable DNA barcode for identifying Quercus species in Lam Dong province.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"291 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86438733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/16518
Beta-glucosidase (BGL) is an enzyme involved in the degradation of cellulose and plays an essential part in many biological processes. Currently, most BGLs applied in the industry are derived from fungi. Exploring novel BGLs with desired properties is attractive. The recombinant BGL derived from microorganisms surrounding white-rot fungus in Cuc Phuong National Park was successfully expressed in Escherichia coli Rosetta 1 (denoted as the GH3S2 gene). The protein GH3S2 was purified by an affinity chromatography column using buffer PBS 50 mM (NaCl-free) pH 7, and the enzyme was collected in buffer containing imidazole 300 mM. The purity and content of the purified protein was determined. The purity of the enzyme obtained after purification reached over 95%. The result of the GH3S2 protein content in the purified sample was 1.54 mg/ml. Thus, amount of the purified GH3S2 obtained from one liter of bacterial culture was 41.80 mg. The final GH3S2 was purified approximately 7.05–fold with a purification yield of 40.06%. The purified enzyme was used to study the properties. This enzyme optimally was activated at 37oC and pH 6.0. At this condition, the enzyme specific activity was 2.23 U/mg in the pNPG substrate, and Km and Vmax were, respectively, 4.55 mM and 4.91 μmol/min. Its activity increased to 200% and 119% in the presence of Ca2+ and Mg2+ and decreased to 33% and 14% when Ni2+ and Cu2+ were added. The enzyme activity was maintained at 70% when the glucose concentration was at 6 mM and then gradually decreased.
{"title":"Purification and characterization of a recombinant beta-glucosidase in Escherichia coli","authors":"","doi":"10.15625/1811-4989/16518","DOIUrl":"https://doi.org/10.15625/1811-4989/16518","url":null,"abstract":"Beta-glucosidase (BGL) is an enzyme involved in the degradation of cellulose and plays an essential part in many biological processes. Currently, most BGLs applied in the industry are derived from fungi. Exploring novel BGLs with desired properties is attractive. The recombinant BGL derived from microorganisms surrounding white-rot fungus in Cuc Phuong National Park was successfully expressed in Escherichia coli Rosetta 1 (denoted as the GH3S2 gene). The protein GH3S2 was purified by an affinity chromatography column using buffer PBS 50 mM (NaCl-free) pH 7, and the enzyme was collected in buffer containing imidazole 300 mM. The purity and content of the purified protein was determined. The purity of the enzyme obtained after purification reached over 95%. The result of the GH3S2 protein content in the purified sample was 1.54 mg/ml. Thus, amount of the purified GH3S2 obtained from one liter of bacterial culture was 41.80 mg. The final GH3S2 was purified approximately 7.05–fold with a purification yield of 40.06%. The purified enzyme was used to study the properties. This enzyme optimally was activated at 37oC and pH 6.0. At this condition, the enzyme specific activity was 2.23 U/mg in the pNPG substrate, and Km and Vmax were, respectively, 4.55 mM and 4.91 μmol/min. Its activity increased to 200% and 119% in the presence of Ca2+ and Mg2+ and decreased to 33% and 14% when Ni2+ and Cu2+ were added. The enzyme activity was maintained at 70% when the glucose concentration was at 6 mM and then gradually decreased.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90327941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/17172
Cao Phong orange (Citrus sinensis Lour) was grown in Cao Phong district, Hoa Binh province. Citrus sinensis is Vietnam’s most valued commercial fruit. In this study, 30 microorganim strains were isolated from the samples of root, stem, and leaf of Cao Phong orange. The ratio of endophytic actinomycetes was found in different parts of the plant: root, stem, and leaf was 37%, 40%, and 23%, respectively. The isolating HBC6-2 was selected because of its high output of α-glucosidase inhibitors from 6 different strains. Morphological, physiological, and biochemical characterization showed that HBC6-2 strain belongs to the Streptomyces sp. The 16S rRNA sequence of HBC6-2 indicated 99% identity to the corresponding sequence of Streptomyces costaricanus, and was registered on GenBank with the code MT 453944.1. Streptomyces costaricanus EBL.HB6 was able to produce melanin yelow pigment, and its aerial and substrate mycelia have brown and yellow-grey pigment on ISP2, ISP3, ISP4, and ISP5 cultivating medium, respectively. The optimal pH range was from 5-10 and temperature from 15-40°C and exhibited salt tolerance up to 3% and utilized the carbon sources such as fructose, xylose, arabinose, cellulose, and rhamnose. In the following investigation, Streptomyces costaricanus EBL.HB6 displayed the highest α-glucosidase inhibitory activity by 68.98% among Streptomyces sp. strains
{"title":"Isolation, selection and evaluation of α-glucosidase inhibitory activity from endophytic Streptomyces sp. isolated from Citrus myrtifolia cultivar in Hoa Binh, Vietnam","authors":"","doi":"10.15625/1811-4989/17172","DOIUrl":"https://doi.org/10.15625/1811-4989/17172","url":null,"abstract":"Cao Phong orange (Citrus sinensis Lour) was grown in Cao Phong district, Hoa Binh province. Citrus sinensis is Vietnam’s most valued commercial fruit. In this study, 30 microorganim strains were isolated from the samples of root, stem, and leaf of Cao Phong orange. The ratio of endophytic actinomycetes was found in different parts of the plant: root, stem, and leaf was 37%, 40%, and 23%, respectively. The isolating HBC6-2 was selected because of its high output of α-glucosidase inhibitors from 6 different strains. Morphological, physiological, and biochemical characterization showed that HBC6-2 strain belongs to the Streptomyces sp. The 16S rRNA sequence of HBC6-2 indicated 99% identity to the corresponding sequence of Streptomyces costaricanus, and was registered on GenBank with the code MT 453944.1. \u0000Streptomyces costaricanus EBL.HB6 was able to produce melanin yelow pigment, and its aerial and substrate mycelia have brown and yellow-grey pigment on ISP2, ISP3, ISP4, and ISP5 cultivating medium, respectively. The optimal pH range was from 5-10 and temperature from 15-40°C and exhibited salt tolerance up to 3% and utilized the carbon sources such as fructose, xylose, arabinose, cellulose, and rhamnose. In the following investigation, Streptomyces costaricanus EBL.HB6 displayed the highest α-glucosidase inhibitory activity by 68.98% among Streptomyces sp. strains","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88162928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/17024
Le Thi Hong Minh, Nguyen Mai Anh, Vu Thi Quyen, Vu Thi Thu Huyen, Phi Thi Dao, Nguyen Thi Thuy Linh, Doan Thi Mai Huong, Pham Van Cuong
The marine environmental conditions are particularly different from terrestrial ones; recent studies have showed that marine actinomycetes might produce many novel compounds with good biological activity. The objective of this study is to isolate and screen actinomycetes strains from the marine environment with activity against pathogenic microorganisms. Fifty strains of actinomycetes were isolated from 40 samples including: sediments, sponges, soft corals, echinoderms... collected from Van Phong Bay area of Khanh Hoa province, Vietnam. The strains fermented in A+ medium and fermentation broths were extracted 5 times with ethyl acetate. The extracts were evaporated under reduced pressure to yield crude extracts. Quantitative assay was used to determine MIC (minimum inhibitory concentration) of extract against 7 test strains, including three Gram-negative bacteria (Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, Salmonella enterica ATCC13076), three Gram-positive bacteria (Enterococcus faecalis ATCC29212, Staphylococcus aureus ATCC25923, Bacillus cereus ATCC 14579), and the yeast Candida albicans ATCC10231. The result of screening showed that: 18/50 strains have shown the antibacterial activities against at least 3 strains of tested microorganisms. In which, strains G650, G654, G657, G666, G675 inhibited three Gram-positive test microorganisms at MIC values from 8 to 64 µg/mL and C. albicans ATCC10231 with MIC values from 2 to 16 µg/mL. In addition, the two strains G657 and G666 had inhibitory effect on P. aeruginosa ATCC27853 và S. enterica ATCC13076 with MIC value 128 µg/mL. Morphological and phylogenetic investigations based on 16S rRNA gene sequences of the selected five strains showed that: strain G650 belonged to species Streptomyces ardesiacus and strain G666 high similarity to the genus Streptomyces; strain G654 showed the highest similarity to the Salinispora arenicola species; strain G657 highest similarity to the Micromonospora aurantiaca; whereas G675 belonged to the Nocardiopsis flavescens species.
{"title":"Isolation and screening antimicrobial activity of actinomycetes from marine organisms samples of the area Khanh Hoa, Vietnam","authors":"Le Thi Hong Minh, Nguyen Mai Anh, Vu Thi Quyen, Vu Thi Thu Huyen, Phi Thi Dao, Nguyen Thi Thuy Linh, Doan Thi Mai Huong, Pham Van Cuong","doi":"10.15625/1811-4989/17024","DOIUrl":"https://doi.org/10.15625/1811-4989/17024","url":null,"abstract":"The marine environmental conditions are particularly different from terrestrial ones; recent studies have showed that marine actinomycetes might produce many novel compounds with good biological activity. The objective of this study is to isolate and screen actinomycetes strains from the marine environment with activity against pathogenic microorganisms. Fifty strains of actinomycetes were isolated from 40 samples including: sediments, sponges, soft corals, echinoderms... collected from Van Phong Bay area of Khanh Hoa province, Vietnam. The strains fermented in A+ medium and fermentation broths were extracted 5 times with ethyl acetate. The extracts were evaporated under reduced pressure to yield crude extracts. Quantitative assay was used to determine MIC (minimum inhibitory concentration) of extract against 7 test strains, including three Gram-negative bacteria (Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, Salmonella enterica ATCC13076), three Gram-positive bacteria (Enterococcus faecalis ATCC29212, Staphylococcus aureus ATCC25923, Bacillus cereus ATCC 14579), and the yeast Candida albicans ATCC10231. The result of screening showed that: 18/50 strains have shown the antibacterial activities against at least 3 strains of tested microorganisms. In which, strains G650, G654, G657, G666, G675 inhibited three Gram-positive test microorganisms at MIC values from 8 to 64 µg/mL and C. albicans ATCC10231 with MIC values from 2 to 16 µg/mL. In addition, the two strains G657 and G666 had inhibitory effect on P. aeruginosa ATCC27853 và S. enterica ATCC13076 with MIC value 128 µg/mL. Morphological and phylogenetic investigations based on 16S rRNA gene sequences of the selected five strains showed that: strain G650 belonged to species Streptomyces ardesiacus and strain G666 high similarity to the genus Streptomyces; strain G654 showed the highest similarity to the Salinispora arenicola species; strain G657 highest similarity to the Micromonospora aurantiaca; whereas G675 belonged to the Nocardiopsis flavescens species.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81939613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/16917
Hoang Thi Lan Anh, Le Thi Thanh Hue, Bui Nguyen Hai Linh, Nguyen Huu Tuan Dung, Dao Duong Minh, Tran Thi Le Quyen, T. Trung
Bacillus genus are Gram-positive, rod shaped, spore-forming, aerobic or facultative anaerobic bacteria, which have the ability to produce a wide variety of enzymes, antimicrobial compounds, vitamins, and carotenoids. Nowadays, Bacillus species have been increasingly proposed for use as probiotics or feed additives as B. amyloliquefaciens, B. licheniformis, B. subtilis, and B. pumilus because of their advantages such as heat-stability of the spores, storage capacity at ambient temperature, and beneficial properties for health. Since microbes are used for customers and livestock, it is critical to substantiate not only the health benefits and efficacy of unique strains but also their safety for the hosts. This study aims to evaluate the in vitro safety and some beneficial properties of Bacillus strains to select potential strains for use in humans or animals. A total of 76 Bacillus strains belonged to the B. amyloliquefaciens and B. subtilis groups were preliminary evaluated for their safety via hemolytic activity. Six non-hemolytic strains were identified and their antibiotic susceptibility, cytotoxicity on the growth of HT29 and Vero cells, extracellular enzyme production, antimicrobial activity, and identification based on 16S rRNA and rpoB gene sequences were studied. Two strains, B. subtilis VTCC 10963 and B. subtilis VTCC 11039, should be considered safe. In addition, these two strains exhibited good extracellular enzyme production (amylase, cellulase, and protease) and strong antibacterial activity against Listeria monocytogenes. Our results support the use of B. subtilis VTCC 10963 and B. subtilis VTCC 11039 for the development of probiotic products and feed additives in the future.
{"title":"In vitro safety evaluation of Bacillus subtilis species complex isolated from Vietnam and their additional beneficial properties","authors":"Hoang Thi Lan Anh, Le Thi Thanh Hue, Bui Nguyen Hai Linh, Nguyen Huu Tuan Dung, Dao Duong Minh, Tran Thi Le Quyen, T. Trung","doi":"10.15625/1811-4989/16917","DOIUrl":"https://doi.org/10.15625/1811-4989/16917","url":null,"abstract":"Bacillus genus are Gram-positive, rod shaped, spore-forming, aerobic or facultative anaerobic bacteria, which have the ability to produce a wide variety of enzymes, antimicrobial compounds, vitamins, and carotenoids. Nowadays, Bacillus species have been increasingly proposed for use as probiotics or feed additives as B. amyloliquefaciens, B. licheniformis, B. subtilis, and B. pumilus because of their advantages such as heat-stability of the spores, storage capacity at ambient temperature, and beneficial properties for health. Since microbes are used for customers and livestock, it is critical to substantiate not only the health benefits and efficacy of unique strains but also their safety for the hosts. This study aims to evaluate the in vitro safety and some beneficial properties of Bacillus strains to select potential strains for use in humans or animals. A total of 76 Bacillus strains belonged to the B. amyloliquefaciens and B. subtilis groups were preliminary evaluated for their safety via hemolytic activity. Six non-hemolytic strains were identified and their antibiotic susceptibility, cytotoxicity on the growth of HT29 and Vero cells, extracellular enzyme production, antimicrobial activity, and identification based on 16S rRNA and rpoB gene sequences were studied. Two strains, B. subtilis VTCC 10963 and B. subtilis VTCC 11039, should be considered safe. In addition, these two strains exhibited good extracellular enzyme production (amylase, cellulase, and protease) and strong antibacterial activity against Listeria monocytogenes. Our results support the use of B. subtilis VTCC 10963 and B. subtilis VTCC 11039 for the development of probiotic products and feed additives in the future.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85984384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/15746
Dang Thi Thu Huong, Dinh Huy Son, Nguyen La Anh
In nature, prebiotics occur not only in fruits and vegetables but also in the seeds from fruits. This study focused on surveying the prebiotic property of the kernel fibers from eight Vietnam’s agro products which were jackfruit, avocado, rambutan, longan, durian, tropical almond, sesame, and lotus seeds. Kernels were investigated for total sugar, soluble protein, and fat contents. The highest total sugar content was found in lotus seed kernel (37.46%) but in kernels from sesame and tropical almond the value only was 2.42 and 3.07% respectively. Rambutan seeds had the highest fatty (54.3%) and soluble protein content (4.49%) while in kernel from durian had the lowest fatty (19.66%) and dissolved protein content (0.69%) among the studied seeds. Kernel powders were defatted, digested by enzymes: α – amylase, glucoamylase and neutrase, then extracted by 96% ethanol to obtain soluble fibers. The prebiotic potential of these fibers was investigated by the growth stimulation of four probiotic strains: Bifidobacterium animalis AP1.2, Bifidobacterium bifidum CNTP 6599, Lactobacillus casei PK2 and Lactobacillus fermentum SBV2. The highest increase of viable cells, compared to the control, was 0.52 lg (CFU/ml) found in medium supplemented with kernel fiber from longan, fermented by L. casei PK2. This fiber also stimulated the growth of four probiotics. However, the soluble fiber content obtained from longan seeds is the lowest among the types surveyed (0.02%). The fiber in jackfruit, avocado or lotus seeds also has a positive prebiotic index, except for L. fermentum SBV2, in which jackfruit and lotus seeds are still commonly used in Vietnamese life.
在自然界中，益生元不仅存在于水果和蔬菜中，也存在于水果的种子中。研究了越南8种农产品菠萝蜜、牛油果、红毛丹、龙眼、榴莲、热带杏仁、芝麻和莲子仁纤维的益生元特性。研究了籽粒的总糖、可溶性蛋白和脂肪含量。莲子仁的总糖含量最高，为37.46%，芝麻仁和热带杏仁的总糖含量分别为2.42%和3.07%。红毛丹种子的脂肪和可溶性蛋白质含量最高(54.3%)，最高(4.49%)，榴莲仁的脂肪和可溶性蛋白质含量最低(19.66%)，最低(0.69%)。将仁粉脱脂，经α -淀粉酶、葡萄糖淀粉酶和中和酶消化，再用96%乙醇提取，得到可溶性纤维。通过动物双歧杆菌AP1.2、两歧双歧杆菌CNTP 6599、干酪乳杆菌PK2和发酵乳杆菌SBV2四种益生菌的生长刺激，研究了这些纤维的益生元潜力。在添加干酪乳杆菌PK2发酵的龙眼仁纤维的培养基中，与对照相比，活细胞增加最多，为0.52 lg (CFU/ml)。这种纤维还刺激了四种益生菌的生长。然而，龙眼种子的可溶性纤维含量是所有类型中最低的(0.02%)。菠萝蜜、鳄梨或莲子中的纤维也具有正的益生元指数，除了L. fermentum SBV2，其中菠萝蜜和莲子仍然是越南人生活中常用的。
{"title":"Assessment of prebiotic property of some Vietnam’s agro products and their applicability","authors":"Dang Thi Thu Huong, Dinh Huy Son, Nguyen La Anh","doi":"10.15625/1811-4989/15746","DOIUrl":"https://doi.org/10.15625/1811-4989/15746","url":null,"abstract":"In nature, prebiotics occur not only in fruits and vegetables but also in the seeds from fruits. This study focused on surveying the prebiotic property of the kernel fibers from eight Vietnam’s agro products which were jackfruit, avocado, rambutan, longan, durian, tropical almond, sesame, and lotus seeds. Kernels were investigated for total sugar, soluble protein, and fat contents. The highest total sugar content was found in lotus seed kernel (37.46%) but in kernels from sesame and tropical almond the value only was 2.42 and 3.07% respectively. Rambutan seeds had the highest fatty (54.3%) and soluble protein content (4.49%) while in kernel from durian had the lowest fatty (19.66%) and dissolved protein content (0.69%) among the studied seeds. Kernel powders were defatted, digested by enzymes: α – amylase, glucoamylase and neutrase, then extracted by 96% ethanol to obtain soluble fibers. The prebiotic potential of these fibers was investigated by the growth stimulation of four probiotic strains: Bifidobacterium animalis AP1.2, Bifidobacterium bifidum CNTP 6599, Lactobacillus casei PK2 and Lactobacillus fermentum SBV2. The highest increase of viable cells, compared to the control, was 0.52 lg (CFU/ml) found in medium supplemented with kernel fiber from longan, fermented by L. casei PK2. This fiber also stimulated the growth of four probiotics. However, the soluble fiber content obtained from longan seeds is the lowest among the types surveyed (0.02%). The fiber in jackfruit, avocado or lotus seeds also has a positive prebiotic index, except for L. fermentum SBV2, in which jackfruit and lotus seeds are still commonly used in Vietnamese life.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90343982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/16871
Nguyen Thi Kieu Oanh, Duong Thi Thuy, Doan Thi Oanh, Vu Thi Nguyet, Nguyen Van Nam
Many scientists are interested in microalgae and cyanobacteria because of their richness in high-value bioactive metabolites (proteins, lipids, vitamins, plant growth regulators, and others). Microalgae and cyanobacteria can be used to produce valuable commodities such as dietary supplements, biofuel, animal feed, and agricultural fertilizer, etc. To improve the economic feasibility of the cyanobacterial product recovery process, it is possible to utilize domestic wastewater as a source of nutrients for their growth. This research focuses on assessing the ability of domestic wastewater treatment and treated domestic wastewater utilization to stimulate BC15 rice-grain sprouting by cyanobacteria Spirulina platensis SP4. Research results showed that S. platensis SP4 grown best in domestic wastewater at the initial density of 0.3 and the wastewater concentration of 100%. The incubation of S. platensis was performed in the laboratory under the condition of 16.8 g/L NaHCO3; aeration during 8 h/day; light: dark cycle of 8:16; light intensity of 5000 lux. Under these conditions S. platensis SP4 could treat N-NH4+, T-N, P-PO43-, T-P and COD well with the treatment efficiency of 96.37, 49.71, 67.05, 65.88 and 95.53%, respectively. The addition of treated domestic wastewater by S. platensis SP4 to BC15 rice grains stimulated the grouting by 99.54 ± 1.25%, which was 1.54 times higher than using the tap water and gave a germination efficiency equivalent to that of the experiments with adding cyanobacteria in standard medium with or without L-tryptophan addition for 48 h. The obtained research results have elucidated the feasibility of employing cyanobacteria in residential wastewater treatment as well as the reuse of treated wastewater for plant development.
{"title":"The domestic wastewater treatment capacity of Spirulina platensis SP4 and the application of the treated wastewater in stimulating rice germination","authors":"Nguyen Thi Kieu Oanh, Duong Thi Thuy, Doan Thi Oanh, Vu Thi Nguyet, Nguyen Van Nam","doi":"10.15625/1811-4989/16871","DOIUrl":"https://doi.org/10.15625/1811-4989/16871","url":null,"abstract":"Many scientists are interested in microalgae and cyanobacteria because of their richness in high-value bioactive metabolites (proteins, lipids, vitamins, plant growth regulators, and others). Microalgae and cyanobacteria can be used to produce valuable commodities such as dietary supplements, biofuel, animal feed, and agricultural fertilizer, etc. To improve the economic feasibility of the cyanobacterial product recovery process, it is possible to utilize domestic wastewater as a source of nutrients for their growth. This research focuses on assessing the ability of domestic wastewater treatment and treated domestic wastewater utilization to stimulate BC15 rice-grain sprouting by cyanobacteria Spirulina platensis SP4. Research results showed that S. platensis SP4 grown best in domestic wastewater at the initial density of 0.3 and the wastewater concentration of 100%. The incubation of S. platensis was performed in the laboratory under the condition of 16.8 g/L NaHCO3; aeration during 8 h/day; light: dark cycle of 8:16; light intensity of 5000 lux. Under these conditions S. platensis SP4 could treat N-NH4+, T-N, P-PO43-, T-P and COD well with the treatment efficiency of 96.37, 49.71, 67.05, 65.88 and 95.53%, respectively. The addition of treated domestic wastewater by S. platensis SP4 to BC15 rice grains stimulated the grouting by 99.54 ± 1.25%, which was 1.54 times higher than using the tap water and gave a germination efficiency equivalent to that of the experiments with adding cyanobacteria in standard medium with or without L-tryptophan addition for 48 h. The obtained research results have elucidated the feasibility of employing cyanobacteria in residential wastewater treatment as well as the reuse of treated wastewater for plant development.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89203052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.15625/1811-4989/17508
Porcine epidemic diarrhea (PED), caused by the Porcine epidemic diarrhea virus (PEDV), is an acute, highly contagious disease of pigs of all ages, especially piglets under one week old, with the mortality rate reaching 95–100%. Developing an effective vaccine against PEDV in Vietnam is urgent. Spike protein containing S1 and S2 subunits is considered the main target for vaccine development, and the S2 subunit contains immunodominant neutralizing epitopes of PEDV. To date, the expression of S2 protein in plants has not been reported and evaluated. In this study, the gene encoding the S2 subunit of a PEDV strain belonging to genotype 2a was amplified, sequenced, and inserted in a pRTRA vector containing the GCN4pII (pII) motif. The plant expression cassette containing S2-pII was then inserted into the pCB301 vector. The Agrobacterium tumefaciens harboring the pCB301-S2-pII vector was transformed into Nicotiana benthamiana leaves via agroinfiltration. The accumulation level of S2-pII protein in tobacco leaves was semi-quantified by Western blot, accounting for approximately 86.7 mg/kg of fresh leaves and 1.47% total soluble protein, which was 294-fold higher than the accumulation level of S1-pII protein in our previous publication. S2-pII protein was successfully purified by immobilized metal affinity chromatography (IMAC). The oligomeric state of S2-pII protein was characterized by size exclusion chromatography (SEC). The S2-pII protein was determined to be a multimer protein with a high molecular weight. These results are the basis for more extended studies to develop a plant-based S2 vaccine against PEDV infection.
{"title":"Transient expression and purification of S2 protein from porcine epidemic diarrhea virus in plants","authors":"","doi":"10.15625/1811-4989/17508","DOIUrl":"https://doi.org/10.15625/1811-4989/17508","url":null,"abstract":"Porcine epidemic diarrhea (PED), caused by the Porcine epidemic diarrhea virus (PEDV), is an acute, highly contagious disease of pigs of all ages, especially piglets under one week old, with the mortality rate reaching 95–100%. Developing an effective vaccine against PEDV in Vietnam is urgent. Spike protein containing S1 and S2 subunits is considered the main target for vaccine development, and the S2 subunit contains immunodominant neutralizing epitopes of PEDV. To date, the expression of S2 protein in plants has not been reported and evaluated. In this study, the gene encoding the S2 subunit of a PEDV strain belonging to genotype 2a was amplified, sequenced, and inserted in a pRTRA vector containing the GCN4pII (pII) motif. The plant expression cassette containing S2-pII was then inserted into the pCB301 vector. The Agrobacterium tumefaciens harboring the pCB301-S2-pII vector was transformed into Nicotiana benthamiana leaves via agroinfiltration. The accumulation level of S2-pII protein in tobacco leaves was semi-quantified by Western blot, accounting for approximately 86.7 mg/kg of fresh leaves and 1.47% total soluble protein, which was 294-fold higher than the accumulation level of S1-pII protein in our previous publication. S2-pII protein was successfully purified by immobilized metal affinity chromatography (IMAC). The oligomeric state of S2-pII protein was characterized by size exclusion chromatography (SEC). The S2-pII protein was determined to be a multimer protein with a high molecular weight. These results are the basis for more extended studies to develop a plant-based S2 vaccine against PEDV infection.","PeriodicalId":23622,"journal":{"name":"Vietnam Journal of Biotechnology","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87195485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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