Biodegradation Of Phenanthrene By A Halophilic Bacterial Consortium And Expression Of Naphthalene Dioxygenase Genes

The degradation of polycyclic aromatic hydrocarbons (PAHs) by bacteria has been widely studied. Polycyclic aromatic hydrocarbons (PAHs) are an important class of refractory organics, and often present in the hypersaline environments. The moderately halophilic bacteria are a class of extreme microorganisms which can be suitable for a wide and high salinity and have low nutritional requirements. Therefore, to study the moderately halophilic microorganisms capable of degrading PAHs has important theoretical significance and application prospects to PAHs pollution control in hypersaline environments.A bacterial consortium degrading phenanthrene was enriched at 30℃at salinity of 10%with initial phenanthrene concentration of 400mg/L. The consortium could degrade phenanthrene at salinities ranging from 0.1%to 20%.In our research the technology of molecular biology and molecular ecology was first utilized in studying degradation process of PAHs-degradation moderately halophilic bacteria in hypersaline environments. The The diversity of the key functional genes (Naphthalene dioxygenase) of the moderate halophilic bacterial consortium was researched. Sequencing of the cloned nahAc fragments showed that different suites of genes were present in the consortium populations.Many of the nahAc gene fragment sequences fell into species which are distinct from the reference nathphrene dioxygenase gene sequences.The purpose of this study is to provide new ideas and theoretical support for develop bioremediation technology to PAHs pollution in hypersaline environments, as well as provide new strains and genes.