Deciphering the Genome Repertoire of Pseudomonas sp. M1 toward b-Myrcene Biotransformation

castro, pedro, soares ; santos, pedro, m.;

Pseudomonas sp. M1 is able to mineralize several unusual substrates of natural and xenobioticorigin, contributing to its competence to thrive indifferent ecological niches. In this work,the genome of M1 strain was resequenced by Illumina Mi Seqtore fine the quality of a published draft by resolving the majority of repeat-rich regions. In silico genome analysis led to the prediction of metabolic pathways involved in biotransformation of several unusual substrates (e.g., plant-derived volatiles), providing clues on the genomic complement required for such bio degrading/bio transformation functionalities. Pseudomonas sp. M1 exhibits aparticular sensory and bio transformation/bio catalysis potential toward b-myrcene, a terpene vastly used in industries worldwide. Therefore, the genomic responsiveness of M1 strain toward b-myrcene was investigated, using an RNA sequencing approach. M1 cells challenged with b-myrcene (compared with cells grown in lactate) under go anextensive alteration of the transcript omee x pression profile, including 1,873 genes evidencing at least 1.5-fold of altered expression (627 upregulated and 1,246 downregulated), toward b-myrcene imposed molecular adaptation and cellular specialization. A thorough data analysis identified a novel 28-kb genomic island, whose expression was strongly stimulated in b-myrcene-supplemented medium, that is essential for b-myrcene catabolism. This island includesb-myrcene-induced genes whose products a reputatively involved in 1)substratesensing, 2)gene expression regulation, and 3)b-myrcene oxidation and bioconversion of b-myrcene derivatives into central metabolism intermediates. Ingeneral, this locus does not show high homology with sequences available in data bases and seems to have evolved through the assembly of several functional blocks acquired from different bacteria, probably, at different evolutionary stages