Genome Analysis of Naphthalene-Degrading Pseudomonas sp. AS1 Harboring the Megaplasmid pAS1

• Published in: Journal of microbiology and biotechnology Vol. 28; no. 2; pp. 330 - 337
• Main Authors: Kim, Jisun, Park, Woojun
• Format: Journal Article
• Language: English
• Published: Korea (South) 한국미생물·생명공학회 01.02.2018
• Subjects: 생물학; polycyclic aromatic hydrocarbons(PAHs); plasmid; Pseudomonas frederiksbergensis; horizontal gene transfer; naphthalene degradation
• ISSN: 1017-7825; 1738-8872
• DOI: 10.4014/jmb.1709.09002

Polycyclic aromatic hydrocarbons (PAHs), including naphthalene, are widely distributed in nature. Naphthalene has been regarded as a model PAH compound for investigating the mechanisms of bacterial PAH biodegradation. sp. AS1 isolated from an arsenic-contaminated site is capable of growing on various aromatic compounds such as naphthalene, salicylate, and catechol, but not on gentisate. The genome of strain AS1 consists of a 6,126,864 bp circular chromosome and the 81,841 bp circular plasmid pAS1. sp. AS1 has multiple dioxygenases and related enzymes involved in the degradation of aromatic compounds, which might contribute to the metabolic versatility of sp. AS1. The pAS1 exhibits extremely high similarity in size and sequences to the well-known naphthalene-degrading plasmid pDTG1 in strain NCIB 9816-4. Two gene clusters involved in the naphthalene degradation pathway were identified on the pAS1. The expression of several genes on the plasmid was upregulated by more than two-fold when naphthalene was used as a sole carbon source. Strains have been isolated at different times and places with different characteristics, but similar genes involved in the degradation of aromatic compounds have been identified on their plasmids, which suggests that the transmissibility of the plasmids might play important roles in the adaptation of the microorganisms to mineralize the compounds.