[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA ...[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA was extracted for amplification of 16S rDNA and gyrB gene.The 16S rDNA and gyrB gene sequences were obtained after sequencing.Sequences were aligned and analyzed via EzBioCloud and NCBI database,and phylogenetic trees were constructed to determine the species relationship of strains.Meantime,they were compared with known strains.[Results]This method could identify 5 standard strains accurately to the species level.The 16S rDNA and gyrB gene sequences were aligned and analyzed in EzBioCloud database and NCBI database.The strain with the max score was consistent with the known strain.And the query cover and ident were both above 99%.[Conclusions]The established molecular biological method for identification of bacterial strains by 16S rDNA and gyrB gene has good accuracy,which effectively solves the problem that the laboratory identification of bacteria relies on traditional methods and the accuracy can not be guaranteed,and further improves the identification ability of laboratory bacterial strains.展开更多
With conserved regions and regions of high variations, 16s rDNA is an important molecular basis for the biological species identification and system evolu- tion. The modem molecular biology with 16s rDNA as the primer...With conserved regions and regions of high variations, 16s rDNA is an important molecular basis for the biological species identification and system evolu- tion. The modem molecular biology with 16s rDNA as the primer can accurately re- veal the diversity of microorganisms species and inheritance, thereby 16s rDNA se- quence analysis has become the main basis for classification and identification of microorganisms. Having overcome the limitations of traditional microculture methods, this method is easy to operate, quick and accurate to detect with high sensitivity, making it widely apply to species identification, community comparative analysis, phytecoenogenesis and the assessment of population diversity. It is a objective classification method with high credibility.展开更多
This study mainly monitored the dominant bacterial populations and identified the spoilage-related microorganisms of braised chicken meat stored under different CO_(2)-modified atmosphere packaging(MAP)during refriger...This study mainly monitored the dominant bacterial populations and identified the spoilage-related microorganisms of braised chicken meat stored under different CO_(2)-modified atmosphere packaging(MAP)during refrigerated storage using a culture-dependent method and 16S rDNA identification.The quality changes and shelf life of the meat were also measured.The growth rate of total viable count(TVC)in braised chicken was slower with an increase of CO_(2) content in MAP,which also occurred in the remaining bacterial species monitored(lactic acid bacteria,Pseudomonas spp.,Brochothrix thermosphacta).The MAP exerted beneficial effects on the quality of braised chicken,as demonstrated by retarding the production of total volatile basic nitrogen(TVB-N)and delaying lipid oxidation(TBARS test).A total of 14 isolates were identified from braised chickens with different packaging at the end of storage,these included P.fragi(6 isolates),P.psychrophila(2 isolates),Enterococcus faecalis(3 isolates),B.thermosphacta(2 isolates),Staphylococcus equorum(1 isolate).展开更多
Twenty-three isolates of soft rot bacteria from konjac corms were examined for their diversity using 16S rDNAs and AFLP technology. Both methods clustered two groups, dependent on their biotype characterization of Pec...Twenty-three isolates of soft rot bacteria from konjac corms were examined for their diversity using 16S rDNAs and AFLP technology. Both methods clustered two groups, dependent on their biotype characterization of Pectobacterium carotovora subsp. carotovora (P.c.c) and Pectobacterium chrysanthemi (P.ch), respectively. Of all isolates, 17 (73.9%) belonged to P. ch, indicated as the main pathogenic bacteria of konjac producing areas in China. The genetic variation among isolates from the same biotype was also rich, not consistent with the distances of the geographic sources.展开更多
[Objectives] This study was conducted to obtain actinomycetes strains having antagonistic effect on Ustilago scitaminea Syd.[Methods] At first, actinomycetes strains were isolated from 22 soil samples in Hainan sugarc...[Objectives] This study was conducted to obtain actinomycetes strains having antagonistic effect on Ustilago scitaminea Syd.[Methods] At first, actinomycetes strains were isolated from 22 soil samples in Hainan sugarcane regions. Then, antagonistic actinomycetes against U. scitaminea were screened by confrontation culture. Finally, the taxonomic status of antagonistic actinomycetes was determined using 16S rDNA.[Results] From the 22 samples, 984 actinomycetes strains were isolated. From all the isolated strains, 23 antagonistic actinomycetes strains were obtained through primary screening, and one strains with better antagonistic effect was then obtained through secondary screening, and designated FAS. 16S rDNA identification showed that strain FAS shared 99% sequence similarity with Streptomyces cealestis US24. A phylogenetic tree was built with MAGE 7.0 software, and the results showed that strain FAS had the shortest genetic distance with S. caelestis US24. Therefore, the actinomycetes FAS was determined as S. caelestis .[Conclusions] This study provides a new biocontrol method for the biological control of sugarcane smut, thereby ensuring sustainable development of sugarcane industry and sugar industry.展开更多
[ Objective] To screen suitable lactic acid bacterium strains from forage corn which can be used as silage additives. [ Method] The lactic acid bacterium strains were isolated by inoculation on MRS solid medium contai...[ Objective] To screen suitable lactic acid bacterium strains from forage corn which can be used as silage additives. [ Method] The lactic acid bacterium strains were isolated by inoculation on MRS solid medium containing calcium carbonate, and they were preliminarily identified through morphological, physiological and biochemical experiments. The acid production efficiency was determined. Twelve strains having strong acid-pro- duction ability were selected, and their salt tolerance and acid tolerance were detected. The sequences of their 16 S rDNA were also analyzed. [ Result] A total of 44 lactic acid bacterium strains were isolated from the forage com. As evidenced by the physiological and biochemical experi- ments, the twelve strains having strong acid-production ability belonged to Leuconostoc, Lactobacillus and Enterococcus, respectively, and they had strong salt tolerance and acid tolerance. According to the sequences of 16 S rDNA, A4, B9, B11, B12 and B14 were Lactobacillus plantarum; A1, A2., A7, A11 and B8 were Leuconostoc mesenteroides dextran subspecies; and AB and A9 were Enterococcus hirae. [ Conclusion ] The lactic acid bacterium strains with strong acid-production ability isolated from forage corn can be developed into silage additives.展开更多
In this study, 43 cellulose-decomposing strains were isolated from deep-litter systems. After preliminary screening with Congo red identification medium and filter paper strip medium, five strains with large transpare...In this study, 43 cellulose-decomposing strains were isolated from deep-litter systems. After preliminary screening with Congo red identification medium and filter paper strip medium, five strains with large transparent circles that disintegrated filter paper strips were obtained. After further liquid fermentation, CMC activity, FPA activity and natural eellulase activity of these five strains were determined, and two cellulose-decomposing strains with higher enzyme activity were screened, which were named F7 and F21. Based on molecular biological identification and phylogenetic analysis of 16S rRNA gene sequences, these two cellulose- decomposing strains were identified as Bacillus subtilis and Streptomyces sp. , respectively.展开更多
根据不同种属细菌的16 S rDNA序列两端的保守性区域设计通用引物,提取菌株的基因组DNA,对菌株的16 S rDNA进行了PCR扩增,对扩增到的目标片段进行了测序,将测序结果与NCBI上已知菌种的16 S rDNA序列进行了BLAST对比,并构建了系统进化树...根据不同种属细菌的16 S rDNA序列两端的保守性区域设计通用引物,提取菌株的基因组DNA,对菌株的16 S rDNA进行了PCR扩增,对扩增到的目标片段进行了测序,将测序结果与NCBI上已知菌种的16 S rDNA序列进行了BLAST对比,并构建了系统进化树。结合传统的形态观察及生理生化特性鉴定,16 S rDNA序列分析结果证实芽孢杆菌Pab02为枯草芽孢杆菌,PAS38为蜡样芽孢杆菌。展开更多
BACKGROUND This study aimed to identify characteristic gut genera in obese and normal-weight children(8-12 years old)using 16S rDNA sequencing.The research aimed to provide insights for mechanistic studies and prevent...BACKGROUND This study aimed to identify characteristic gut genera in obese and normal-weight children(8-12 years old)using 16S rDNA sequencing.The research aimed to provide insights for mechanistic studies and prevention strategies for childhood obesity.Thirty normal-weight and thirty age-and sex-matched obese children were included.Questionnaires and body measurements were collected,and fecal samples underwent 16S rDNA sequencing.Significant differences in body mass index(BMI)and body-fat percentage were observed between the groups.Analysis of gut microbiota diversity revealed lowerα-diversity in obese children.Differences in gut microbiota composition were found between the two groups.Prevotella and Firmicutes were more abundant in the obese group,while Bacteroides and Sanguibacteroides were more prevalent in the control group.AIM To identify the characteristic gut genera in obese and normal-weight children(8-12-year-old)using 16S rDNA sequencing,and provide a basis for subsequent mechanistic studies and prevention strategies for childhood obesity.METHODS Thirty each normal-weight,1:1 matched for age and sex,and obese children,with an obese status from 2020 to 2022,were included in the control and obese groups,respectively.Basic information was collected through questionnaires and body measurements were obtained from both obese and normal-weight children.Fecal samples were collected from both groups and subjected to 16S rDNA sequencing using an Illumina MiSeq sequencing platform for gut microbiota diversity analysis.RESULTS Significant differences in BMI and body-fat percentage were observed between the two groups.The Ace and Chao1 indices were significantly lower in the obese group than those in the control group,whereas differences were not significant in the Shannon and Simpson indices.Kruskal-Wallis tests indicated significant differences in unweighted and weighted UniFrac distances between the gut microbiota of normal-weight and obese children(P<0.01),suggesting substantial disparities in both the species and quantity of gut microbiota between the two groups.Prevotella,Firmicutes,Bacteroides,and Sanguibacteroides were more abundant in the obese and control groups,respectively.Heatmap results demonstrated significant differences in the gut microbiota composition between obese and normal-weight children.CONCLUSION Obese children exhibited lowerα-diversity in their gut microbiota than did the normal-weight children.Significant differences were observed in the composition of gut microbiota between obese and normal-weight children.展开更多
从烟叶调制过程中温度达68℃阶段的叶片上分离得到一株能降解烟碱的菌株,编号为YC-68,该菌经常规的形态、生理生化分析,确定为芽孢杆菌。根据该菌16 S rDNA恒定区的保守性设计了一对通用引物,扩增其16 S rDNA序列,将扩增的产物进行回收...从烟叶调制过程中温度达68℃阶段的叶片上分离得到一株能降解烟碱的菌株,编号为YC-68,该菌经常规的形态、生理生化分析,确定为芽孢杆菌。根据该菌16 S rDNA恒定区的保守性设计了一对通用引物,扩增其16 S rDNA序列,将扩增的产物进行回收后进行测序,把测序后的结果提交到GenBank利用BLAST进行序列同源性分析。经过分析鉴定YC-68菌株为芽孢杆菌属的蜡状芽孢杆菌。展开更多
以取自四川省不同地区的牦牛粪便、肠道内容物为材料,用MRS琼脂双层培养基进行厌氧培养,分离到50株乳酸菌,经生化鉴定为嗜热链球菌(2株)、乳酸乳球菌(1株)、保加利亚乳杆菌(5株)、嗜粪乳杆菌(10株)、嗜酸乳杆菌(8株)、乳酸乳杆菌(9株)...以取自四川省不同地区的牦牛粪便、肠道内容物为材料,用MRS琼脂双层培养基进行厌氧培养,分离到50株乳酸菌,经生化鉴定为嗜热链球菌(2株)、乳酸乳球菌(1株)、保加利亚乳杆菌(5株)、嗜粪乳杆菌(10株)、嗜酸乳杆菌(8株)、乳酸乳杆菌(9株)、肠乳杆菌(10株)、弯曲乳杆菌(5株)。采用乳酸菌16 S rDNA通用引物,对分离的8种菌的16 S rDNA一段可变区序列进行扩增,均得到大小约470 bp的产物;扩增产物经纯化、测序后与GenBank中标准菌株的核甘酸序列比较,同源性均大于97．5％,同源性分析与生化试验的结果是一致的。证实,牦牛肠道和粪便的乳酸菌较为丰富,且乳杆菌的数量较多,这可能与牦牛复杂的生长环境有关。展开更多
基金Supported by Special Project of"Grassland Talents"in Inner Mongolia.
文摘[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA was extracted for amplification of 16S rDNA and gyrB gene.The 16S rDNA and gyrB gene sequences were obtained after sequencing.Sequences were aligned and analyzed via EzBioCloud and NCBI database,and phylogenetic trees were constructed to determine the species relationship of strains.Meantime,they were compared with known strains.[Results]This method could identify 5 standard strains accurately to the species level.The 16S rDNA and gyrB gene sequences were aligned and analyzed in EzBioCloud database and NCBI database.The strain with the max score was consistent with the known strain.And the query cover and ident were both above 99%.[Conclusions]The established molecular biological method for identification of bacterial strains by 16S rDNA and gyrB gene has good accuracy,which effectively solves the problem that the laboratory identification of bacteria relies on traditional methods and the accuracy can not be guaranteed,and further improves the identification ability of laboratory bacterial strains.
文摘With conserved regions and regions of high variations, 16s rDNA is an important molecular basis for the biological species identification and system evolu- tion. The modem molecular biology with 16s rDNA as the primer can accurately re- veal the diversity of microorganisms species and inheritance, thereby 16s rDNA se- quence analysis has become the main basis for classification and identification of microorganisms. Having overcome the limitations of traditional microculture methods, this method is easy to operate, quick and accurate to detect with high sensitivity, making it widely apply to species identification, community comparative analysis, phytecoenogenesis and the assessment of population diversity. It is a objective classification method with high credibility.
基金financially supported by China Agriculture Research System (Beijing, China, CARS-41-Z06)Nanjing Professor Huang Food Technology Co., Ltd.
文摘This study mainly monitored the dominant bacterial populations and identified the spoilage-related microorganisms of braised chicken meat stored under different CO_(2)-modified atmosphere packaging(MAP)during refrigerated storage using a culture-dependent method and 16S rDNA identification.The quality changes and shelf life of the meat were also measured.The growth rate of total viable count(TVC)in braised chicken was slower with an increase of CO_(2) content in MAP,which also occurred in the remaining bacterial species monitored(lactic acid bacteria,Pseudomonas spp.,Brochothrix thermosphacta).The MAP exerted beneficial effects on the quality of braised chicken,as demonstrated by retarding the production of total volatile basic nitrogen(TVB-N)and delaying lipid oxidation(TBARS test).A total of 14 isolates were identified from braised chickens with different packaging at the end of storage,these included P.fragi(6 isolates),P.psychrophila(2 isolates),Enterococcus faecalis(3 isolates),B.thermosphacta(2 isolates),Staphylococcus equorum(1 isolate).
文摘Twenty-three isolates of soft rot bacteria from konjac corms were examined for their diversity using 16S rDNAs and AFLP technology. Both methods clustered two groups, dependent on their biotype characterization of Pectobacterium carotovora subsp. carotovora (P.c.c) and Pectobacterium chrysanthemi (P.ch), respectively. Of all isolates, 17 (73.9%) belonged to P. ch, indicated as the main pathogenic bacteria of konjac producing areas in China. The genetic variation among isolates from the same biotype was also rich, not consistent with the distances of the geographic sources.
基金Supported by Natural Science Foundation of China(31471555)Special Fund for Basic Scientific Research of Central Nonprofit Research Institutes(1630052016010)The Earmarked Fund for Modern Agro-industry(Sugar Crop Industry)Technology Research System(CARS-170301)
文摘[Objectives] This study was conducted to obtain actinomycetes strains having antagonistic effect on Ustilago scitaminea Syd.[Methods] At first, actinomycetes strains were isolated from 22 soil samples in Hainan sugarcane regions. Then, antagonistic actinomycetes against U. scitaminea were screened by confrontation culture. Finally, the taxonomic status of antagonistic actinomycetes was determined using 16S rDNA.[Results] From the 22 samples, 984 actinomycetes strains were isolated. From all the isolated strains, 23 antagonistic actinomycetes strains were obtained through primary screening, and one strains with better antagonistic effect was then obtained through secondary screening, and designated FAS. 16S rDNA identification showed that strain FAS shared 99% sequence similarity with Streptomyces cealestis US24. A phylogenetic tree was built with MAGE 7.0 software, and the results showed that strain FAS had the shortest genetic distance with S. caelestis US24. Therefore, the actinomycetes FAS was determined as S. caelestis .[Conclusions] This study provides a new biocontrol method for the biological control of sugarcane smut, thereby ensuring sustainable development of sugarcane industry and sugar industry.
基金supported by the funds from the National Natural Science Foundation of China (30760008)
文摘[ Objective] To screen suitable lactic acid bacterium strains from forage corn which can be used as silage additives. [ Method] The lactic acid bacterium strains were isolated by inoculation on MRS solid medium containing calcium carbonate, and they were preliminarily identified through morphological, physiological and biochemical experiments. The acid production efficiency was determined. Twelve strains having strong acid-pro- duction ability were selected, and their salt tolerance and acid tolerance were detected. The sequences of their 16 S rDNA were also analyzed. [ Result] A total of 44 lactic acid bacterium strains were isolated from the forage com. As evidenced by the physiological and biochemical experi- ments, the twelve strains having strong acid-production ability belonged to Leuconostoc, Lactobacillus and Enterococcus, respectively, and they had strong salt tolerance and acid tolerance. According to the sequences of 16 S rDNA, A4, B9, B11, B12 and B14 were Lactobacillus plantarum; A1, A2., A7, A11 and B8 were Leuconostoc mesenteroides dextran subspecies; and AB and A9 were Enterococcus hirae. [ Conclusion ] The lactic acid bacterium strains with strong acid-production ability isolated from forage corn can be developed into silage additives.
基金Supported by Science and Technology Development Program of Guangxi Academy of Agricultural Sciences(2015JM23,GNK2012JM10)
文摘In this study, 43 cellulose-decomposing strains were isolated from deep-litter systems. After preliminary screening with Congo red identification medium and filter paper strip medium, five strains with large transparent circles that disintegrated filter paper strips were obtained. After further liquid fermentation, CMC activity, FPA activity and natural eellulase activity of these five strains were determined, and two cellulose-decomposing strains with higher enzyme activity were screened, which were named F7 and F21. Based on molecular biological identification and phylogenetic analysis of 16S rRNA gene sequences, these two cellulose- decomposing strains were identified as Bacillus subtilis and Streptomyces sp. , respectively.
文摘根据不同种属细菌的16 S rDNA序列两端的保守性区域设计通用引物,提取菌株的基因组DNA,对菌株的16 S rDNA进行了PCR扩增,对扩增到的目标片段进行了测序,将测序结果与NCBI上已知菌种的16 S rDNA序列进行了BLAST对比,并构建了系统进化树。结合传统的形态观察及生理生化特性鉴定,16 S rDNA序列分析结果证实芽孢杆菌Pab02为枯草芽孢杆菌,PAS38为蜡样芽孢杆菌。
文摘BACKGROUND This study aimed to identify characteristic gut genera in obese and normal-weight children(8-12 years old)using 16S rDNA sequencing.The research aimed to provide insights for mechanistic studies and prevention strategies for childhood obesity.Thirty normal-weight and thirty age-and sex-matched obese children were included.Questionnaires and body measurements were collected,and fecal samples underwent 16S rDNA sequencing.Significant differences in body mass index(BMI)and body-fat percentage were observed between the groups.Analysis of gut microbiota diversity revealed lowerα-diversity in obese children.Differences in gut microbiota composition were found between the two groups.Prevotella and Firmicutes were more abundant in the obese group,while Bacteroides and Sanguibacteroides were more prevalent in the control group.AIM To identify the characteristic gut genera in obese and normal-weight children(8-12-year-old)using 16S rDNA sequencing,and provide a basis for subsequent mechanistic studies and prevention strategies for childhood obesity.METHODS Thirty each normal-weight,1:1 matched for age and sex,and obese children,with an obese status from 2020 to 2022,were included in the control and obese groups,respectively.Basic information was collected through questionnaires and body measurements were obtained from both obese and normal-weight children.Fecal samples were collected from both groups and subjected to 16S rDNA sequencing using an Illumina MiSeq sequencing platform for gut microbiota diversity analysis.RESULTS Significant differences in BMI and body-fat percentage were observed between the two groups.The Ace and Chao1 indices were significantly lower in the obese group than those in the control group,whereas differences were not significant in the Shannon and Simpson indices.Kruskal-Wallis tests indicated significant differences in unweighted and weighted UniFrac distances between the gut microbiota of normal-weight and obese children(P<0.01),suggesting substantial disparities in both the species and quantity of gut microbiota between the two groups.Prevotella,Firmicutes,Bacteroides,and Sanguibacteroides were more abundant in the obese and control groups,respectively.Heatmap results demonstrated significant differences in the gut microbiota composition between obese and normal-weight children.CONCLUSION Obese children exhibited lowerα-diversity in their gut microbiota than did the normal-weight children.Significant differences were observed in the composition of gut microbiota between obese and normal-weight children.
文摘从烟叶调制过程中温度达68℃阶段的叶片上分离得到一株能降解烟碱的菌株,编号为YC-68,该菌经常规的形态、生理生化分析,确定为芽孢杆菌。根据该菌16 S rDNA恒定区的保守性设计了一对通用引物,扩增其16 S rDNA序列,将扩增的产物进行回收后进行测序,把测序后的结果提交到GenBank利用BLAST进行序列同源性分析。经过分析鉴定YC-68菌株为芽孢杆菌属的蜡状芽孢杆菌。
文摘以取自四川省不同地区的牦牛粪便、肠道内容物为材料,用MRS琼脂双层培养基进行厌氧培养,分离到50株乳酸菌,经生化鉴定为嗜热链球菌(2株)、乳酸乳球菌(1株)、保加利亚乳杆菌(5株)、嗜粪乳杆菌(10株)、嗜酸乳杆菌(8株)、乳酸乳杆菌(9株)、肠乳杆菌(10株)、弯曲乳杆菌(5株)。采用乳酸菌16 S rDNA通用引物,对分离的8种菌的16 S rDNA一段可变区序列进行扩增,均得到大小约470 bp的产物;扩增产物经纯化、测序后与GenBank中标准菌株的核甘酸序列比较,同源性均大于97．5％,同源性分析与生化试验的结果是一致的。证实,牦牛肠道和粪便的乳酸菌较为丰富,且乳杆菌的数量较多,这可能与牦牛复杂的生长环境有关。
