A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of i...A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of incubation, and could also remove 100% of fluorene, 98.93% of phenanthrene and 65.73% of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis(DGGE) was used to investigate the microbial community shifts in five different carbon sources(including TPH, saturated hydrocarbons, fluorene, phenanthrene and pyrene). The test results indicated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudomonas sp. could survive in the five kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that specific bacterial phylotypes were associated with different contaminants and complex interactions between bacterial species, and the medium conditions influenced the biodegradation capacity of the microbial communities involved in bioremediation processes.展开更多
Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal mi ties involved in the biodegradation of Enteromorpha polysaccharides ...Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal mi ties involved in the biodegradation of Enteromorpha polysaccharides （EP） were sel- dom reported. In order to obtain the EP-degrading micro-community, the intestines of Siganus oramin was obtained to isolate the micro-communities, which were enriched by 0.3% of EP as the sole carbon source. A stable micro-community with EP degradative capability was achieved after seven generations of subculture, named H1. Results showed that H1 was able to degrade 75% of EP within 24 hours, and the activity of EP lyases reached 500 U mL-1 in 32 hours. With denaturing gradient gel electrophoresis （DGGE） and 16S rRNA gene clone library analysis, ten bacteria closely related to Marinomonas pontica, Microbacterium sp., Leucobacter chironomi, Cyclobacterium sp., Algoriphagus winogradskyi, Pseudoalteromonas sp. and Vibrio sp. were determined. Furthermore, compared with the DGGE bands sequence and the clone library analysis, the dominant bacteria of the EP-biodegrading mi- cro-community were Pseudoalteromonas sp. and Vibrio sp., with the respective proportion of 38% and 46%, and they should play an important role in EP degradation together with other degrading bacteria in the micro-community H1.展开更多
To better understand the effect of salinity on denitrification communities, soils along a salinity gradient （ranging from 7.32 to 1.70 mS cm 1） in a wetland along the Yellow Sea coastline in Jiangsu Province, China,...To better understand the effect of salinity on denitrification communities, soils along a salinity gradient （ranging from 7.32 to 1.70 mS cm 1） in a wetland along the Yellow Sea coastline in Jiangsu Province, China, were studied using both culture-dependent and -independent methods. Culture efforts yielded 82 isolates in total, 81.7% of which were close relatives of Bacillus sp. based on partial sequences of their 16S rRNA genes. Denaturing gradient gel electrophoresis （DGGE） analysis based on 16S rRNA sequences suggested possible existence of bacterial community succession along the salinity gradient. Clone library analysis based on nosZ gene sequences （coding nitrous oxide reductase） showed that operational taxonomic units （OTUs） associated with α-proteobacteria dominated in all three soils, whereas those associated with β- and γ-subdivisions showed a clear succession. In the high salinity soil, only the OTUs associated with a-subdivision were found. In the medium salinity soil, small proportions of β- （6.5%） and γ-associated （19.6%） OTUs were found. In the low salinity soil, the proportions were further increased to 33% and 25% for β- and γ-Proteobacteria, respectively. Statistic analysis using Unifrac P test showed that nosZ-communities in different saline soils were significantly different from each other. It could be concluded that α-subdivision of nosZ-community tended to be sustained in high salinity environments whereas β and γ-subdivisions, especially the former, tended to be sustained in low salinity environments. Salinity was the key determinant of nosZ-community composition in the environment.展开更多
基金supported by the Scientific Research Fund of Liaoning Provincial Education Department (L2014148)
文摘A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of incubation, and could also remove 100% of fluorene, 98.93% of phenanthrene and 65.73% of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis(DGGE) was used to investigate the microbial community shifts in five different carbon sources(including TPH, saturated hydrocarbons, fluorene, phenanthrene and pyrene). The test results indicated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudomonas sp. could survive in the five kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that specific bacterial phylotypes were associated with different contaminants and complex interactions between bacterial species, and the medium conditions influenced the biodegradation capacity of the microbial communities involved in bioremediation processes.
基金supported by the National Natural Science Foundation of China (Nos.41476150 and 41276179)Guangdong Natural Science Foundation (No.S2011030005257)the Science and Technology Project of Guangdong Province (Nos.2012A031100009 and 2012B060400016)
文摘Micro-communities are supposed to have more potential functions of biodegradation of polysaccharides than single strain; however, the intestinal mi ties involved in the biodegradation of Enteromorpha polysaccharides （EP） were sel- dom reported. In order to obtain the EP-degrading micro-community, the intestines of Siganus oramin was obtained to isolate the micro-communities, which were enriched by 0.3% of EP as the sole carbon source. A stable micro-community with EP degradative capability was achieved after seven generations of subculture, named H1. Results showed that H1 was able to degrade 75% of EP within 24 hours, and the activity of EP lyases reached 500 U mL-1 in 32 hours. With denaturing gradient gel electrophoresis （DGGE） and 16S rRNA gene clone library analysis, ten bacteria closely related to Marinomonas pontica, Microbacterium sp., Leucobacter chironomi, Cyclobacterium sp., Algoriphagus winogradskyi, Pseudoalteromonas sp. and Vibrio sp. were determined. Furthermore, compared with the DGGE bands sequence and the clone library analysis, the dominant bacteria of the EP-biodegrading mi- cro-community were Pseudoalteromonas sp. and Vibrio sp., with the respective proportion of 38% and 46%, and they should play an important role in EP degradation together with other degrading bacteria in the micro-community H1.
基金Supported by the National Natural Science Foundation of China (No. 41071177)
文摘To better understand the effect of salinity on denitrification communities, soils along a salinity gradient （ranging from 7.32 to 1.70 mS cm 1） in a wetland along the Yellow Sea coastline in Jiangsu Province, China, were studied using both culture-dependent and -independent methods. Culture efforts yielded 82 isolates in total, 81.7% of which were close relatives of Bacillus sp. based on partial sequences of their 16S rRNA genes. Denaturing gradient gel electrophoresis （DGGE） analysis based on 16S rRNA sequences suggested possible existence of bacterial community succession along the salinity gradient. Clone library analysis based on nosZ gene sequences （coding nitrous oxide reductase） showed that operational taxonomic units （OTUs） associated with α-proteobacteria dominated in all three soils, whereas those associated with β- and γ-subdivisions showed a clear succession. In the high salinity soil, only the OTUs associated with a-subdivision were found. In the medium salinity soil, small proportions of β- （6.5%） and γ-associated （19.6%） OTUs were found. In the low salinity soil, the proportions were further increased to 33% and 25% for β- and γ-Proteobacteria, respectively. Statistic analysis using Unifrac P test showed that nosZ-communities in different saline soils were significantly different from each other. It could be concluded that α-subdivision of nosZ-community tended to be sustained in high salinity environments whereas β and γ-subdivisions, especially the former, tended to be sustained in low salinity environments. Salinity was the key determinant of nosZ-community composition in the environment.
