Isolation, phylogenesis and degradation characters of DDT-degrading bacterium strain DB-1.

A bacterium strain DB-1 capable of degrading DDT under the aerobic condition was isolated and screened from the sewer sludge of a pestcide factory. Based on the phenotype, physiological and biochemical characteristics, and the phylogenetic analysis of 16S rDNA sequence, the strain DB-1 was identified preliminarily as Sphingomonas sp. This strain could degrade DDT in inorganic salt liquor culture base of DDT (40mg/L) containing yeast cream (40mg/L), with degradation efficiency reaching 83.6% in 10 days. The strain DB-1 growed better at 25~30℃, with most adaptable pH value of 8.0.