摘要：AbstractEnvironmental pollution due to di-ethyl phthalate (DEP) is one of the major concerns all over the world. This is probably the first study regarding the biodegradation of DEP by newly isolatedPseudomonas juntendistrain CCNU-SK1,P. putidastrain CCNU-SK2 andP. nitritireducensstrain CCNU-SK3. Bacterial strains were isolated by morphological, biochemical, physiological and16SrDNA gene sequencing techniques. The biodegradation of DEP was quantified, and degradation kinetics were studied by using high-performance liquid chromatography. The optimum growth of bacteria for strain CCNU-SK1 was obtained at 28 °C, pH 8, DEP (500 mg/L), NaCl (1.5%), half-life (10.19 h); in case of strain CCNU-SK2: 33 °C, pH 7, DEP (400 mg/L), NaCl (1.5%), half-life (13.86 h) and for strain CCNU-SK3: 33 °C, pH 7, DEP (500 mg/L), NaCl (1.75%), half-life (12.6 h). Strain CCNU-SK1 with lowest half-life period was the most efficient bacteria for biodegradation of DEP compared to other isolated strains. More than 99% of all DEP were biodegraded within the 4 days and the complete utilization of (50 mg/L) DEP occurred within 24 h by all strains. All of them were capable of metabolizing not only DEP but also other phthalate esters (PAEs) such as DMP (Di-methyl phthalate), DBP (Di-butyl phthalate), DOP (Di-octyl phthalate), BBP (Benzyl butyl phthalate), DEHP (Di-2-ethylhexyl phthalate) and PA (Phthalic acid), making them the promising agents for the bioremediation in the PAEs contaminated sites.
