Exiguobacterium alkaliphilum 12/1 Genome sequencing and assembly

The emergence of alkaliphilic bacteria in human-created ecosystems can be of great evolutionary importance and commercial application. Bacteria belonging to phylum Firmicutes exhibit a plethora of adverse condition survival adaptability. Here we report the genome sequence of an alkaliphile, Exiguobacterium sp. 12/1, which was isolated from wastewater drained sludge of a beverage industry in India. It grows in a broad range of pH from 6.5 to 12 and has the capability to neutralize the external medium. To investigate the underlying principles of survival at varying pH, we carried out RNA-seq analysis of the bacteria grown at pH7 and pH10 by de novo assembly of transcripts. NGS assisted Comparative genomics and transcriptomics approach lead to the identification of a set of protein coding genes that may have evolved as a consequence of adaptation to alkaline environment. These acquired proteins primarily belong to transporters including Mrp and cadmium resistance class of proteins. Variation in the transcript levels for these genes was also observed at different pH. This integrative approach of genome sequencing, comparative genomics and transcriptome profiling provides insights into the mechanisms, which may have led to the evolution of a novel species as a by-product of industrialization. Genomic features that are unique to survival in alkaline conditions could also be useful in developing systems for treatment of industrial wastewater.