Isolation and functional analysis of a glycolipid producing Rhodococcus sp. strain IITR03 with potential for degradation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT)

• Published in: Bioresource technology 2014-09, Vol.167, p.398-406
• Main Authors: Bajaj, Abhay, Mayilraj, Shanmugam, Mudiam, Mohana Krishna Reddy, Patel, Devendra Kumar, Manickam, Natesan
• Format: Article
• Language: English
• Subjects: Biodegradation; Biodegradation, Environmental - drug effects; Biological and medical sciences; Biosurfactant; Biotechnology; Catechol; Catechol 1,2-Dioxygenase - genetics; Catechol 1,2-Dioxygenase - metabolism; Chloroaromatic compound; Contamination; DDT; DDT - metabolism; Degradation; Fatty Acids - analysis; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Gene sequencing; Genes; Glycolipids - biosynthesis; Molecular Sequence Data; Phenotype; Phylogeny; Pyruvic Acid - pharmacology; Reference Standards; Rhodococcus; Rhodococcus - enzymology; Rhodococcus - growth & development; Rhodococcus - isolation & purification; Rhodococcus - metabolism; Rhodococcus sp; RNA, Ribosomal, 16S - genetics; Spectrophotometry, Ultraviolet; Strain; Succinic Acid - pharmacology
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.06.007

•A Rhodococus sp. able to degrade DDT and chlorobenzoate was isolated.•DDE, DDD and DDMU were identified as metabolites of DDT by the bacterium.•The bacterium possessed catechol 1,2-dioxygenase to form lower intermediates.•Trehalolipid was identified as the surfactant produced by the Rhodococus sp. A 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) degrading bacterium strain IITR03 producing trehalolipid was isolated and characterized from a pesticides contaminated soil. The strain IITR03 was identified as a member of the genus Rhodococcus based on polyphasic studies. Under aqueous culture conditions, the strain IITR03 degraded 282μM of DDT and could also utilize 10mM concentration each of 4-chlorobenzoic acid, 3-chlorobenzoic acid and benzoic acid as sole carbon and energy source. The catechol 1,2-dioxygenase enzyme activity resulted in conversion of catechol to form cis,cis-muconic acid. Cloning and sequencing of partial nucleotide sequence of catechol 1,2-dioxygenase gene (cat) from strain IITR03 revealed its similarity to catA gene present in Rhodococcus sp. strain Lin-2 (97% identity) and Rhodococcus strain AN22 (96% identity) degrading benzoate and aniline, respectively. The results suggest that the strain IITR03 could be useful for field bioremediation studies of DDT-residues and chlorinated aromatic compounds present in contaminated sites.