Isolation And Study Of Highly Effective Organics-degrading Bacteria

Landfill leachate is produced during the course of landfilling due to the water in the garbage as well as the permeation of rain and snow. It is highly concentrated and polluting organic wasterwater with big smell, high chroma and various toxic organic pollutants, which exerts a great impact on human health and living environment. Nowadays, bio-treatment is widely used in the treatment process of landfill leachate instead of physicochemical treatment, which is both high in cost and limited to operation conditions. This research takes the landfill leachate sample A and B from Shanghai Lao Gang Solid Waste Landfill as the object of study. Composition of organic pollutants was detected and analyzed by GC-MS. Three highly effective organics-degrading strains were isolated. The research also verified the degrading activity of the three strains and optimized their cultivating conditions.PDM-XP and DQ8 were isolated from contaminated soils near Da Qing Oil Field. DQ8 was identified to be Pseudomonas aeruginosa through 16 s r DNA sequencing, whereas PDM-XP is a mixture of 38 different strains. Both PDM-XP and DQ8 were able to grow in landfill leachate sample A through acclimation. L-62, isolated from landfill leachate sample B, is composed of two strains, Pseudomonas nitroreducens and Pseudomonas pseudoalcaligenes. L-62 was able to grow in 80% landfill leachate sample B.The optimum culture condition of PDM-XP is 30℃, 200 rpm, under which octadecane, nonadecane and eicosane can by degraded by 75.6%, 53.0% and 45.6% within 24 hours, respectively. The optimum culture condition of DQ8 is 30 ℃, 250 rpm, and octadecane, nonadecane and eicosane can by degraded by 85.9%, 72.6% and 30.1% respectively within 24 hours under the optimal temperature and rotation rate. L-62 was able to degrade 11 different organics in landfill leachate sample B, including alkanes, phenols, carboxylic acids, ketones and heterocyclic compounds.