Genomic Insights Into A Novel, Alkalitolerant Nitrogen Fixing Bacteria, Azonexus sp. Strain ZS02

摘要

Alkaline environments represent a significant challenge to the growth of micro-organisms. Despitethis, there are a number of alkaline environments which contain active microbial communities. Herewe describe the genome of a diazotrophic, alkalitolerant strain of Azonexus, which was isolated froma microcosm seeded with hyperalkaline soils resulting from lime depositions. The isolate has agenome size 3.60 Mb with 3431 protein coding genes. The proteome indicated the presence ofgenes associated with the cycling of nitrogen, in particular the fixation of atmospheric nitrogen.Although closely related to Azonexus hydrophilus strain d8-1 by both 16S (97.9%) and in silico gDNA(84.1%) relatedness, the isolate demonstrates a pH tolerance above that reported for this strain.The proteome contained genes for the complete Na+/H+ antiporter (subunits A to G) forcytoplasmic pH regulation; this may account for the phenotypic characteristics of this strain whichexhibited optimal growth conditions of pH 9 and 30°C.