Research On Diversity Of Given Functional Microorganism In Polluted Environments

To understand the composition and structure of denitrifying communities in the Jiaozhou Bay, the diversity of denitrifying bacterial nirS gene from the sediments of Jiaozhou Bay was investigated by using a PCR-based cloning approach. A total of 331 clones were obtained from 5 stations. Restriction analysis of cloned nirS showed a total of 132 Operational Taxonomic Units (OTUs) were obtained from all samples. The number of OTUs of each station ranged from 30 to 44. All OTUs were sequenced. The similarity of the nirS sequences to their best-match known genes retrieved from the GenBank database varied from 62 to 100. Molecular phylogenetic analysis of nirS sequences retrieved from the sediments or water column of 12 sea areas assigned the nirS sequences into 7 major clusters (Marine ClusterⅠ-Ⅶ). Marine ClusterⅦwas divided into 7 sub-clusters with 50% similarity and Marine ClusterⅦg was specific for Jiaozhou Bay. Cluster Environment, Jackknife Cluster and Principal Coordinates Analysis (PCA) indicated that the denitrifying communities of A5, Y1 and D1 were more similar, however, B2 and C4 were not. The correlation analysis between geographic locations and its biogeochemical data indicated that multi-environment factors controlled the community structure of denitrifying bacteria. Terrestrial pollution, hydrodynamic factor and grain size of sediments should be key factors to affect the diversity of denitrifying bacteria.Environmental microbiology investigation was performed to determine the molecular diversity ofβ-lactamase genes among ampicillin-resistant bacteria from Jiaozhou Bay. With multiplex PCR,β-lactamase genes detected in 93.8% of the bacterial isolates were identified as Enterobacteriaceae. The most frequently detected gene was bla_TEM, followed by bla_SHV, Most of the isolates (68.8%) were positive for the intI1 integrase gene. Anthropogenic contamination from onshore sewage processing plants might contribute predominantly to theβ-lactamase gene reservoir in the studied coastal waters. Environmental antibiotic-resistant bacteria and resistance genes may serve as bioindicators of coastal environmental quality or biotracers of the potential contamination sources. Integron-mediated horizontal transference plays a particularly important role in the spread of multidrug resistance in aquatic environments.A crude oil degrading strain DW-1, diesel oil as sole carbon, was isolated from oil-polluted wastewater. The strain was identified as Pseudomonas sp. with physiological experiments and analysis of Biolog. Orthogonal factorial experiment showed pH 8.5, salinity 30‰and ratio of nitrogen to phosphorus 10:1 are the optimal growth conditions. Bacteria strain DW-1 cultivated for 48h were inoculated in inorganic culture medium oil with 3g/L oil. The oil degradation rate was about 70% and the highest was 80.32%. The characteristics of flocks in seawater medium indicated the strain had feasibility to disposal marine oil contamination.