Selection And Breeding Of Phenol-Degrading Bacterium And Its Immobilization To Deal With Phenol-Containing Wastewater

Phenol which comes extensively from all kinds of industrial process is serious pollutant in the environment and it is toxic to human beings extremely. Thus, the removal of it from industrial effluents is of great importance. One of the effective possible solutions to resolve phenol contamination problem is by bioremediation, however, the ability of nomal phenol-degrading strain is limited. This research's aims are to select an efficient phenol-degrading strain, then to immobilize it in order to increase its degrading capability and in favor of recycling. Thus the immobilized cells can fit for industrial process,further.An efficient phenol-degrading strain was selected through the inactivated parental strain protoplasts fusion method by the name Pseudomonas stutzri JFL 2008 in this research, it's degrading capability was up to 1800mg·L^-1, increased by 20% compared with that of its parents.The efficiently phenol-degrading strain Pseudomonas stutzri JFL 2008 was immobilized with sodium alginate. Optimal preparation conditions of the immobilized strain are carried out by the cross-test experiments. The best condition is to use sodium alginate of 4%, CaCl₂ of 4%, cells of 0.4g and to calcify for 2 hours. The immobilized cells' degrading capability was up to 2200mg·L^-1, increased by 22% compared with the free cells. Temperature and pH value' effects to those immobilized cells' performance are investigated The results show that the optimal phenol-degrading temperature is 30℃, and the optimal pH value is 5-9.The complete sequence of the Pseudomonas sp. JFL 2008 strain's 16S ribosomal DNA was cloned by the technology PCR and was found to be homogeneous the rate of 99% to many members of Pseudomonas sp. in Gene Bank of the Internet, so we can identify it as Pseudomonas sp. at molecular level.The sequence of the Pseudomonas sp. JFL 2008 strain's phenol hydroxylase gene was cloned by technology PCR and was compared with the sequence already been reported in Gene Bank of the Internet. Software analytic results showed that the nucleotide sequence of this fragment and its deduced amino acid sequence shared 99.77% and 100% homology respectively with the phenol hydroxylase gene and its deduced amino acid sequence of phenol-degrading strain Pseudomonas sp.D28864.1, which can confirm that the function of phenol-degrading capability was examined at molecular level.