Biodegradation of phthalic acid esters by a newly isolated Mycobacterium sp YC-RL4 and the bioprocess with environmental samples

作者：Ren, Lei; Jia, Yang; Ruth, Nahurira; Qiao, Cheng; Wang, Junhuan; Zhao, Baisuo; Yan, Yanchun^*

来源：Environmental Science and Pollution Research, 2016, 23(16): 16609-16619.

DOI：10.1007/s11356-016-6829-4

• Phthalic acid esters
• Mycobacterium sp.
• Metabolic mechanism
• Cell surface hydrophobicity
• Bioremediation

Bacterial strain YC-RL4, capable of utilizing phthalic acid esters (PAEs) as the sole carbon source for growth, was isolated from petroleum-contaminated soil. Strain YC-RL4 was identified as Mycobacterium sp. by 16S rRNA gene analysis and Biolog tests. Mycobacterium sp. YC-RL4 could rapidly degrade dibutyl phthalate (DBP), diethyl phthalate (DEP), dimethyl phthalate (DMP), dicyclohexyl phthalate (DCHP), and di-(2-ethylhexyl) phthalate (DEHP) under both individual and mixed conditions, and all the degradation rates were above 85.0 % within 5 days. The effects of environmental factors which might affect the degrading process were optimized as 30 degrees C and pH 8.0. The DEHP metabolites were detected by HPLC-MS and the degradation pathway was deduced tentatively. DEHP was transformed into phthalic acid (PA) via mono (2-ethylhexyl) phthalate (MEHP) and PA was further utilized for growth via benzoic acid (BA) degradation pathway. Cell surface hydrophobicity (CSH) assays illuminated that the strain YC-RL4 was of higher hydrophobicity while grown on DEHP and CSH increased with the higher DEHP concentration. The degradation rates of DEHP by strain YC-RL4 in different environmental samples was around 62.0 to 83.3 % and strain YC-RL4 survived well in the soil sample. These results suggested that the strain YC-RL4 could be used as a potential and efficient PAE degrader for the bioremediation of contaminated sites.

• 出版日期2016-8
• 单位中国农业科学院