[Objective] The aim was to isolate the strains resistant to plant pathogenic fungi from Southern Ocean and study their phylogenetic relationship and antimicrobial spectrum. [Method] Agar diffusion method was adopted t...[Objective] The aim was to isolate the strains resistant to plant pathogenic fungi from Southern Ocean and study their phylogenetic relationship and antimicrobial spectrum. [Method] Agar diffusion method was adopted to screen antimicrobial strains and determine the antimicrobial spectrum. Phylogenetic relationship of the strains was analyzed by neighbor-joining method of the Mega 4.0 software. [Result] Twenty antimicrobial strains were screened from seawater of Southern Ocean collected during the 27^th Chinese Antarctic Scientific Expedition. Molecular identification and phyloge- netic analysis indicated that two antimicrobial strains were members of Pseu- domonas, two strains were members of Psychrobacter, and the other 16 trains were members of Pseudoalteromonas. The antimicrobial spectrum of four strains which had higher antimicrobial activity indicated that the strains 312, 83-1 and 195 greatly inhibited the growth of Fusarium oxysporum, Rhizoctonia solani K（Jhn, Phytophthora capsici Leonian, Verticillium dahliae, Alternaria solani, Thanatephoru scucumeris and Phomopsis asparagi （Sacc）; strain 312-1 had obvious antimicrobial effect on the six of the plant pathogens except R. solani. [Conclusion] Four strains which had higher antimicrobial effect were obtained and should be further studied for development and application.展开更多
To improve the hydrogen evolution rate in continuous hydrogen production of a fermentative hydrogen-producing bacteria strain B49 (AF481148 in EMBL), 4% immobilized cells by polyvinyl alcohol-boric acid method, with t...To improve the hydrogen evolution rate in continuous hydrogen production of a fermentative hydrogen-producing bacteria strain B49 (AF481148 in EMBL), 4% immobilized cells by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate in a column reactor obtain hydrogen yield of 2.31 mol H2/mol glucose and hydrogen evolution rate of 1435.4 ml/L culture·h respectively at medium retention time of 2 h with a medium containing l0 g glucose/L. As the cell density in gel beads is increased to 8%, hydrogen yield and hydrogen evolution rate for l0 g glucose/L are 2.34 mol H2/mol glucose and 2912.4 ml/L culture · h respectively at medium retention time of 1 h, and for molasses wastewater COD of 7505.9 mg/L hydrogen production potential of 205.6 ml/g COD and hydrogen evolution rate of 2057.7 ml/L culture·h at hydraulic retention time of 0.75 h are observed. In the continuous culture pH value keeps around 3.9 by self regulation.展开更多
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
基金Supported by Public Science and Technology Research Projects of Ocean (201005032-2)~~
文摘[Objective] The aim was to isolate the strains resistant to plant pathogenic fungi from Southern Ocean and study their phylogenetic relationship and antimicrobial spectrum. [Method] Agar diffusion method was adopted to screen antimicrobial strains and determine the antimicrobial spectrum. Phylogenetic relationship of the strains was analyzed by neighbor-joining method of the Mega 4.0 software. [Result] Twenty antimicrobial strains were screened from seawater of Southern Ocean collected during the 27^th Chinese Antarctic Scientific Expedition. Molecular identification and phyloge- netic analysis indicated that two antimicrobial strains were members of Pseu- domonas, two strains were members of Psychrobacter, and the other 16 trains were members of Pseudoalteromonas. The antimicrobial spectrum of four strains which had higher antimicrobial activity indicated that the strains 312, 83-1 and 195 greatly inhibited the growth of Fusarium oxysporum, Rhizoctonia solani K（Jhn, Phytophthora capsici Leonian, Verticillium dahliae, Alternaria solani, Thanatephoru scucumeris and Phomopsis asparagi （Sacc）; strain 312-1 had obvious antimicrobial effect on the six of the plant pathogens except R. solani. [Conclusion] Four strains which had higher antimicrobial effect were obtained and should be further studied for development and application.
文摘To improve the hydrogen evolution rate in continuous hydrogen production of a fermentative hydrogen-producing bacteria strain B49 (AF481148 in EMBL), 4% immobilized cells by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate in a column reactor obtain hydrogen yield of 2.31 mol H2/mol glucose and hydrogen evolution rate of 1435.4 ml/L culture·h respectively at medium retention time of 2 h with a medium containing l0 g glucose/L. As the cell density in gel beads is increased to 8%, hydrogen yield and hydrogen evolution rate for l0 g glucose/L are 2.34 mol H2/mol glucose and 2912.4 ml/L culture · h respectively at medium retention time of 1 h, and for molasses wastewater COD of 7505.9 mg/L hydrogen production potential of 205.6 ml/g COD and hydrogen evolution rate of 2057.7 ml/L culture·h at hydraulic retention time of 0.75 h are observed. In the continuous culture pH value keeps around 3.9 by self regulation.
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.
