AUTHOR=Ren Lei , Jia Yang , Zhang Rui , Lin Zhong , Zhen Zhen , Hu Hanqiao , Yan Yanchun 

TITLE=Insight Into Metabolic Versatility of an Aromatic Compounds-Degrading Arthrobacter sp. YC-RL1

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.02438

DOI=10.3389/fmicb.2018.02438

ISSN=1664-302X

ABSTRACT=<p>The genus <italic>Arthrobacter</italic> is ubiquitously distributed in different natural environments. Many xenobiotic-degrading <italic>Arthrobacter</italic> strains have been isolated and described; however, few have been systematically characterized with regard to multiple interrelated metabolic pathways and the genes that encode them. In this study, the biodegradability of seven aromatic compounds by <italic>Arthrobacter</italic> sp. YC-RL1 was investigated. Strain YC-RL1 could efficiently degrade <italic>p</italic>-xylene (PX), naphthalene, phenanthrene, biphenyl, <italic>p</italic>-nitrophenol (PNP), and bisphenol A (BPA) under both separated and mixed conditions. Based on the detected metabolic intermediates, metabolic pathways of naphthalene, biphenyl, PNP, and BPA were proposed, which indicated that strain YC-RL1 harbors systematic metabolic pathways toward aromatic compounds. Further, genomic analysis uncovered part of genes involved in the proposed pathways. Both intradiol and extradiol ring-cleavage dioxygenase genes were identified in the genome of strain YC-RL1. Meanwhile, gene clusters predicted to encode the degradation of biphenyl (<italic>bph</italic>), para-substituted phenols (<italic>npd</italic>) and protocatechuate (<italic>pca</italic>) were identified, and <italic>bphA1A2BCD</italic> was proposed to be a novel biphenyl-degrading gene cluster. The complete metabolic pathway of biphenyl was deduced via intermediates and functional gene analysis (<italic>bph</italic> and <italic>pca</italic> gene clusters). One of the these genes encoding ring-cleavage dioxygenase in <italic>bph</italic> gene cluster, a predicted 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC) gene, was cloned and its activity was confirmed by heterologous expression. This work systematically illuminated the metabolic versatility of aromatic compounds in strain YC-RL1 via the combination of metabolites identification, genomics analysis and laboratory experiments. These results suggested that strain YC-RL1 might be a promising candidate for the bioremediation of aromatic compounds pollution sites.</p>