A bacteria strain for the degradation of hydrolyzed polyacrylamide （HPAM） was isolated from a curing pot in HPAM distribution station of Daqing Oilfield using Hungate anaerobic technique. The isolate was investigate...A bacteria strain for the degradation of hydrolyzed polyacrylamide （HPAM） was isolated from a curing pot in HPAM distribution station of Daqing Oilfield using Hungate anaerobic technique. The isolate was investigated from morphological, physiological, biochemical and molecular characterization. It is a Gram-negative, shortbacillus, non-spore-forming anaerobic bacteria with an optimum growth at 8.0 pH at 40℃. It can reduce sulfate to I-I2S. Alignment of 16S ribosomal DNA and 16S-23S ribosomal DNA intergenic spacer sequences suggests that this isolate is closely related to the Enterobacter cloacae. The isolate is identified as a new strain belonging to Enterobacter genus, temporarily named as Enterobacter cloacae 17. Analysis results of infrared spectroscopy （IR） show that the bacteria can use HPAM as the only carbon source, change the structure of HPAM polymer surface, and realize the hydrolysis of amide to carboxyl group by hydrolysis mechanism. It can degrade the side chain and change some functional groups, which obviously decreases the viscosity. GC-MS analysis indicates that the determined low-molecular weight degradation products of HPAM are polyacrylamide fragments with duplet bond, epoxy as well as carbonyl group, but most of them are acrylamide oligomer derivatives.展开更多
[ Objective ] The paper was to screen bacterial strain with significant antagonistic effect against Phytophthora infestans, so as to provide basis for further development and utilization of antagonistic bacteria to in...[ Objective ] The paper was to screen bacterial strain with significant antagonistic effect against Phytophthora infestans, so as to provide basis for further development and utilization of antagonistic bacteria to inhibit P. infestans and control potato late bright. [ Method] Plate dual culture and filter paper method were used to determine the inhibition effect of strains in vivo, fermentation broth and bacterial liquid of 61 strains against P. infestans and the resistance-induction effect of SR13-2 strain. [ Result] The inhibition rate of 24 strains among 61 tested strains against mycelial growth of P. infestans was greater than 60%, and the inhibi- tion effect of HT-6 strain was the strongest with the inhibition rate of 89.92%. However, fermentation broth of all tested strains had no significant inhibition effect against P. infestans, while the inhibition effect of bacterial liquid of most strains was significantly higher than strain in vivo; the inhibition effect of $34-1 strain was the strongest with inhibition rate of 91.50%. The bacterial liquid of SR13-2 strain was found to have significant resistance-induction effect with protective rate of 60%. [ Conclusion] The inhibition effect of strains in vivo and fermentation broth of antagonistic strains S34-1 and SR13-2 had no relationship with each other, while bacterial liquid had great application potential in controlling potato late bright.展开更多
Five bacterial strains, which are able to grow and to disintegratedibenzothiophene (DBT) and diben- zothiophene sulfone (DBTO_2) infossil fuels, are isolated. Analysis of products of DBT metabolizedby these strains sh...Five bacterial strains, which are able to grow and to disintegratedibenzothiophene (DBT) and diben- zothiophene sulfone (DBTO_2) infossil fuels, are isolated. Analysis of products of DBT metabolizedby these strains shows that different bacteria strains oxidized DBTby different pathways. The isolated strains R-6, $-16, $-9 and R-8can metabolize DBT to DBTO_2 and 3-hydroxybiphenyl (HBP), which areidentified as Bacillus brevis, Bacillus Sphaericus, Nocardiagloberula and Pseudomonas delafieldii respectively.展开更多
本研究旨在了解新疆地区山羊原奶中乳酸菌的益生特性、加工特性和安全性,以期为开发功能性乳品奠定一定的基础。实验采用16S rRNA基因测序结合Rep-PCR指纹分型技术对分离出的乳酸菌菌株进行遗传差异分析,检测它们对酸和胆盐的耐受性并...本研究旨在了解新疆地区山羊原奶中乳酸菌的益生特性、加工特性和安全性,以期为开发功能性乳品奠定一定的基础。实验采用16S rRNA基因测序结合Rep-PCR指纹分型技术对分离出的乳酸菌菌株进行遗传差异分析,检测它们对酸和胆盐的耐受性并对耐受性较好的菌株进行模拟胃肠液耐受性、细胞表面特性(疏水性和自凝聚)、抗菌活性、工艺逆境耐受性(溶菌酶、热)及药敏试验,来评价菌株的体外益生特性和安全性,通过主成分分析筛选最优的益生菌株。研究从15份山羊乳样品中共分离得到23株乳酸菌,包括Leuconostoc mesenteroides(9株)、Lactiplantibacillus plantarum(6株)、Latilactobacillus curvatus(4株)、Enterococcus faecium(2株)、Enterococcus durans(2株)。基于对酸和胆盐耐受性进行初筛的结果表明,有7株菌具有较好的耐受性。其中,2株植物乳植物杆菌(L. plantarum SY43-10和L. plantarum SY43-4)的模拟胃液和肠液处理后活菌数均高于5 lg CFU/mL;24 h自凝集率大于27%、并具有良好疏水性;热和溶菌酶处理后的活菌数仍大于7 lg CFU/mL;药敏试验显示2株菌对氨苄西林和氯霉素表现敏感,对头孢西丁、红霉素和青霉素表现中度敏感或敏感。因此,菌株SY43-10和SY43-4可作为优良的益生菌株,通过体内实验进一步应用于发酵乳品和功能性产品。展开更多
基金Sponsored by the Country from Branch Fund Significant International Cooperation Item(Grant No.50521140075)
文摘A bacteria strain for the degradation of hydrolyzed polyacrylamide （HPAM） was isolated from a curing pot in HPAM distribution station of Daqing Oilfield using Hungate anaerobic technique. The isolate was investigated from morphological, physiological, biochemical and molecular characterization. It is a Gram-negative, shortbacillus, non-spore-forming anaerobic bacteria with an optimum growth at 8.0 pH at 40℃. It can reduce sulfate to I-I2S. Alignment of 16S ribosomal DNA and 16S-23S ribosomal DNA intergenic spacer sequences suggests that this isolate is closely related to the Enterobacter cloacae. The isolate is identified as a new strain belonging to Enterobacter genus, temporarily named as Enterobacter cloacae 17. Analysis results of infrared spectroscopy （IR） show that the bacteria can use HPAM as the only carbon source, change the structure of HPAM polymer surface, and realize the hydrolysis of amide to carboxyl group by hydrolysis mechanism. It can degrade the side chain and change some functional groups, which obviously decreases the viscosity. GC-MS analysis indicates that the determined low-molecular weight degradation products of HPAM are polyacrylamide fragments with duplet bond, epoxy as well as carbonyl group, but most of them are acrylamide oligomer derivatives.
基金Supported by Natural Science Foundation of Heibei Province(C2011201003)~~
文摘[ Objective ] The paper was to screen bacterial strain with significant antagonistic effect against Phytophthora infestans, so as to provide basis for further development and utilization of antagonistic bacteria to inhibit P. infestans and control potato late bright. [ Method] Plate dual culture and filter paper method were used to determine the inhibition effect of strains in vivo, fermentation broth and bacterial liquid of 61 strains against P. infestans and the resistance-induction effect of SR13-2 strain. [ Result] The inhibition rate of 24 strains among 61 tested strains against mycelial growth of P. infestans was greater than 60%, and the inhibi- tion effect of HT-6 strain was the strongest with the inhibition rate of 89.92%. However, fermentation broth of all tested strains had no significant inhibition effect against P. infestans, while the inhibition effect of bacterial liquid of most strains was significantly higher than strain in vivo; the inhibition effect of $34-1 strain was the strongest with inhibition rate of 91.50%. The bacterial liquid of SR13-2 strain was found to have significant resistance-induction effect with protective rate of 60%. [ Conclusion] The inhibition effect of strains in vivo and fermentation broth of antagonistic strains S34-1 and SR13-2 had no relationship with each other, while bacterial liquid had great application potential in controlling potato late bright.
基金Supported by the special funds for major state basic research project (No.G2000048004) and SINOPEC.
文摘Five bacterial strains, which are able to grow and to disintegratedibenzothiophene (DBT) and diben- zothiophene sulfone (DBTO_2) infossil fuels, are isolated. Analysis of products of DBT metabolizedby these strains shows that different bacteria strains oxidized DBTby different pathways. The isolated strains R-6, $-16, $-9 and R-8can metabolize DBT to DBTO_2 and 3-hydroxybiphenyl (HBP), which areidentified as Bacillus brevis, Bacillus Sphaericus, Nocardiagloberula and Pseudomonas delafieldii respectively.
文摘本研究旨在了解新疆地区山羊原奶中乳酸菌的益生特性、加工特性和安全性,以期为开发功能性乳品奠定一定的基础。实验采用16S rRNA基因测序结合Rep-PCR指纹分型技术对分离出的乳酸菌菌株进行遗传差异分析,检测它们对酸和胆盐的耐受性并对耐受性较好的菌株进行模拟胃肠液耐受性、细胞表面特性(疏水性和自凝聚)、抗菌活性、工艺逆境耐受性(溶菌酶、热)及药敏试验,来评价菌株的体外益生特性和安全性,通过主成分分析筛选最优的益生菌株。研究从15份山羊乳样品中共分离得到23株乳酸菌,包括Leuconostoc mesenteroides(9株)、Lactiplantibacillus plantarum(6株)、Latilactobacillus curvatus(4株)、Enterococcus faecium(2株)、Enterococcus durans(2株)。基于对酸和胆盐耐受性进行初筛的结果表明,有7株菌具有较好的耐受性。其中,2株植物乳植物杆菌(L. plantarum SY43-10和L. plantarum SY43-4)的模拟胃液和肠液处理后活菌数均高于5 lg CFU/mL;24 h自凝集率大于27%、并具有良好疏水性;热和溶菌酶处理后的活菌数仍大于7 lg CFU/mL;药敏试验显示2株菌对氨苄西林和氯霉素表现敏感,对头孢西丁、红霉素和青霉素表现中度敏感或敏感。因此,菌株SY43-10和SY43-4可作为优良的益生菌株,通过体内实验进一步应用于发酵乳品和功能性产品。
