Structural and functional genomics of plasmid pSinA of Sinorhizobium sp. M14 encoding genes for the arsenite oxidation and arsenic resistance

Abstract

Plasmid pSinA of Sinorhizobium sp. M14 (Alphaproteobacteria) is the first described, natural, self-transferable plasmid harboring a complete set of genes for oxidation of arsenite. Removal of this plasmid from cells of the host strain caused the loss of resistance to arsenic and heavy metals (Cd, Co, Zn and Hg) and abolished the ability to grow on minimal salt medium supplemented with sodium arsenite as the sole energy source. Plasmid pSinA was introduced into other representatives of Alphaproteobacteria which resulted in acquisition of new abilities concerning arsenic resistance and oxidation, as well as heavy metals resistance. Microcosm experiments revealed that plasmid pSinA can also be transferred via conjugation into other indigenous bacteria from microbial community of As-contaminated soils, including representatives of Alpha-and Gammaproteobacteria. Analysis of "natural" transconjugants showed that pSinA is functional (expresses arsenite oxidase) and is stably maintained in their cells after approximately 60 generations of growth under nonselective conditions. This work clearly demonstrates that pSinA is a self-transferable, broad-host-range plasmid, which plays an important role in horizontal transfer of arsenic metabolism genes.

Insight into heavy metal resistome of soil psychrotolerant bacteria originating from King George Island (Antarctica)

“…LM20, and Sinorhizobium sp. M14 were used as the positive controls in PCRs, as these strains previously gave positive results for the presence of particular resistance genes (Drewniak et al 2013;Dziewit et al 2015;Romaniuk et al 2017).…”

Construction of the recombinant broad-host-range plasmids providing their bacterial hosts arsenic resistance and arsenite oxidation ability

“…1). The functionality of the arsenite oxidation (AIO) and arsenic resistance (ARS) modules was confirmed by genomic analysis of the entire plasmid pSinA in our previous study (Drewniak et al, 2013). As recipients for the constructed recombinant vectors we have used strains that represent different phylogenetic and physiological groups of bacteria, which are commonly found in many heavy metal contaminated environments (e.g.…”

“…Bacterial strains tested for arsenite oxidation abilities were cultivated at 22 • C in mineral salt minimal (MSM) medium containing 100 mg L −1 or 200 mg L −1 sodium arsenite (electron donor) and supplemented with yeast extract (0.04% w/v) as a source of additional organic compounds and vitamins (Drewniak et al, 2013). For the analysis of the ability to grow on environmental samples, sterile mine water from an ancient gold mine in Zloty Stok was used.…”

“…Not all arsenite-oxidizing bacteria use the energy potential of the reactions they carry out, and some treat the arsenite oxidation process only as a detoxification mechanism. Most of the bacteria which oxidize As(III) are chemolithoautotrophs able to grow under aerobic (Battaglia-Brunet et al, 2006;Drewniak et al, 2013;Muller et al, 2003) or anaerobic conditions (Oremland et al, 2002;Rhine et al, 2006;Sun et al, 2009). For some of them, technologies of bioremediation of arsenic-polluted areas were proposed.…”

“…As a source of functional phenotypic modules, encoding proteins involved in arsenite oxidation and arsenic resistance, plasmid pSinA of Sinorhizobium sp. M14 (Drewniak et al, 2013) was used. This plasmid harbours an "arsenic gene island" with all the genes necessary for arsenite oxidation and arsenic resistance (Fig.…”