Salicylate and phthalate pathways contributed differently on phenanthrene and pyrene degradations in Mycobacterium sp. WY10

• Published in: Journal of hazardous materials 2019-02, Vol.364, p.509-518
• Main Authors: Sun, Shanshan, Wang, Haizhen, Chen, Yuanzhi, Lou, Jun, Wu, Laosheng, Xu, Jianming
• Format: Article
• Language: English
• Subjects: Biodegradation; Biodegradation, Environmental; Functional gene; Genome, Bacterial; Mycobacterium; Mycobacterium - genetics; Mycobacterium - metabolism; PAHs; Pathway; Phenanthrenes - metabolism; Phthalic Acids - metabolism; Pyrenes - metabolism; Salicylic Acid - metabolism; Soil Pollutants - metabolism
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2018.10.064

[Display omitted] •Mycobacterium sp. WY10 is an efficient PAHs-degrader with 53 functional genes.•A detailed PHE and PYR metabolism maps were constructed with metabolic results.•PHE was degraded in a dominant phthalate pathway and a minor salicylate pathway.•Both phthalate and salicylate pathways played important roles on PYR degradation. Mycobacterium sp. WY10 was a highly effective PAHs-degrading bacterium that can degrade phenanthrene (PHE, 100 mg L−1) completely within 60 h and 83% of pyrene (PYR, 50 mg L-1) in 72 h. In this study, ten and eleven metabolites, respectively, were identified in PHE and PYR degradation cultures, and a detailed PHE and PYR metabolism maps were constructed based on the metabolic results. The strain WY10 degraded PHE and PYR with initial dioxygenation mainly on 3,4- and 4,5-carbon positions, respectively. Thereafter, PYR degradation entered the PHE degradation pathway via the ortho-cleavage. It was observed that the “lower pathway” of PHE and PYR degradations were different. Based on the kinetics of residual metabolites, PHE was degraded in a dominant phthalate pathway and a minor salicylate pathway. However, both phthalate and salicylate pathways played important roles on PYR degradation. The WY10 genome revealed there were fifty-three genes related to PAHs degradations, including a complete gene set for PHE and PYR degradation via the phthalate pathway. The candidate gene/ORF, BOH72_19755, encoding salicylate synthase might contribute in the salicylate pathway.