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A bacterium capable of utilizing 3-phenoxybenzoic acid (3-PBA) as sole carbon source was isolated from petroleum-contaminated soil. This bacterium, designated as BA3, was identified as Sphingobium sp. according to its physiological & biochemical characteristic and the similarity analysis of its 16S rDNA sequence. Strain BA3 was able to degrade 99% of 100 mg x L(-1) 3-phenoxybenzoic acid within 60 h. The optimal pH and temperature for the degradation were 7.0 and 30 degrees C, respectively. The degradation efficiency was related positively to initial inoculum size. The pyrethroid hydrolase gene (pytH) gene was amplified from the genomic DNA of Sphingobium sp. JZ-2 by PCR. Recombinant plasmids pPYTH was constructed by ligating pytH gene into the broad host vector pBBRMCS- 5. Under the help of plasmid RK600, pPYTH was transferred into Sphingobium sp. BA3 to construct engineering strain BA3-pytH; Fenpropathrin degradation experiments showed that strain JZ-2 was able to degrade only 60% of 50 mg x L(-1) fenpropathrin in 48 h while engineering strain BA3-pytH was able to degrade over 95% of 50 mg x L(-1) fenpropathrin under the same conditions. Even more, BA3-pytH could rapidly degrade 3-PBA, metabolic products of pyrethroid insecticides, eliminating the inhibition of 3-PBA to pyrethroid hydrolase. Therefore, in contrast to strain JZ-2, engineering strain BA3-pytH had more advantages in bioremediation of pyrethroid insecticides contaminated environment.

A bacterial strain that degrades 17alpha-ethynylestradiol (EE2) was isolated from activated sludge of wastewater treatment plant treating wastewater from pharmacy factory mainly producing contraceptive medicine in Beijing, China. Based on its morphology, physiological and biochemical characters, as well as 16S rDNA sequence analysis, this strain was identified as Sphingobacterium sp. JCR5. Strain JCR5 can use EE2 as sole carbon and energy source for growth. The optimal temperature and pH for strain JCR5 utilizing EE2 was 25 approximately 40 degrees C and 7 approximately 9, respectively. Metal ions such as Ni2+, Mn2+, Cu2+ and Fe3+ promote growth of strain JCR5, and some metal ions such as Zn2+, Ag+, Pb2+, Ca2+ and Al3+ inhibit its growth. The degradation process for EE2 with initial concentration of 30mg x L(-1) indicated that the degradation rate of EE2 by strain JCR5 within 10 days was 87%.