Details zur Publikation
|DOI / URL||Link|
|Titel (primär)||Functional characterization of a 28-kilobase catabolic island from Pseudomonas sp. M1 involved in biotransformation of β-myrcene and related plant-derived volatiles|
|Autor||Soares-Castro, P.; Montenegro-Silva, P.; Heipieper, H.J.; Santos, P.M.|
|Journal / Serie||Applied and Environmental Microbiology|
Pseudomonas sp. M1 is able to mineralize highly hydrophobic and recalcitrant compounds such as benzene, phenol and their methylated/halogenated derivatives, as well as the backbone of several monoterpenes. The ability to use such spectrum of compounds as sole carbon source is, most probably, associated with a genetic background evolved under different environmental constraints. The outstanding performance of M1 strain regarding β-myrcene catabolism was elucidated in this work, with focus on the biocatalytical potential of β-myrcene-associated core-code, comprised in a 28-kb genomic island (GI), predicted to be organized in 8 transcriptional units.
Functional characterization of this locus with promoter-probes and analytical approaches validated the genetic organization predicted in silico and associated the β-myrcene-induced promoter activity to the production of β-myrcene derivatives. Notably, by using a whole-genome mutagenesis strategy, different genotypes of the 28-kb GI were generated, resulting in the identification of a novel putative β-myrcene hydroxylase, responsible for the initial oxidation of β-myrcene into myrcen-8-ol, and a sensor-like regulatory protein, whose inactivation abolished the myr+ trait of M1 cells.
Moreover, it was demonstrated that the range of monoterpene substrates of M1 enzymatic repertoire, besides β-myrcene, also includes other acyclic (e.g. β-linalool) and cyclic molecules (e.g. R-(+)-limonene and (-)-β-pinene). Our findings are the cornerstone for following metabolic engineering approaches and hint a major role of the 28-kb GI in the biotransformation of a broad monoterpene-backbone spectrum for its future biotechnological applications.
Importance Information regarding microbial systems able to biotransformation monoterpenes, especially β-myrcene, is limited and focused mainly in non-systematic metabolite identification. Full and detailed knowledge at the genetic, protein, metabolite and regulatory level is essential in order to set a model organism or a catabolic system as biotech tool. Moreover, molecular characterization about reported systems is scarce, almost inexistent, limiting advances in the development of optimized cell-factories recurring to new generation of metabolic engineering platforms. This study provide new insights on the intricate molecular functionalities associated with β-myrcene catabolism in Pseudomonas, envisaging the production of molecular knowledge-base about the underlying catalytic and regulatory mechanisms of plant-derived volatile catabolic pathways
|Soares-Castro, P., Montenegro-Silva, P., Heipieper, H.J., Santos, P.M. (2017):
Functional characterization of a 28-kilobase catabolic island from Pseudomonas sp. M1 involved in biotransformation of β-myrcene and related plant-derived volatiles
Appl. Environ. Microb. 83 (9), e03112-16