Omics Analysis Of The Unique Environmental Adaptation Mechanism Of Haloalkaliphiles

Haloalkaliphiles are extremophilic microorganisms capable growth in extreme environment characterized by both high salinity and extreme alkalinity.Haloalkaliphiles requires growth conditions with an Na~+concentration of at least 0.5 mol/L and an alkaline pH of 9 for optimum conditions.Their unique features enable them to make significant application value in many fields.In this paper,the draft whole genome of the anaerobic,extremely halophilic,obligately alkaliphilic,and thermotolerant bacterium Natranaerobius trueperi DSM 18760~T and the mesophilic haloalkaliphile Natronolimnobius baerhuesisis CGMCC 1.3597~T was performed using an Illumina HiSeq 4000.The genome sequence of extremely halophilic alkalithermophilic archaeon Natronolimnobius aegyptiacus JW/NM-HA 15~T was performed using the Pacific Biosciences sequencing platform.Genome sequence analysis revealed the presence of a large group of genes associated with the unique mechanism of extremely conditions.The proteomic analysis of Natranaerobius thermophilus JW/NM-WN-LF~T was carried out using isobaric tags for relative and absolute quantitation.A total of 2213 proteins were detected by analyzing the total proteins of the strain Natranaerobius thermophilus JW/NM-WN-LF~T under 3M Na~+,pH8.8 and 42°C with 4M Na~+,pH9.8 and 52°C conditions.Comparing the total proteins of different conditions,there were 203 up-regulated proteins and147 down-regulated proteins.Proteins related to glycine betaine synthesis and transport were detected,indicating that the bacteria can adapt to the extreme environments by using compatible solute.In addition,some proteins associated with Na~+and K~+transport were detected.These proteins help maintain intracellular pH homeostasis and cytoplasmic acidification in a high-alkaline environment.RNA-seq sequencing was used to analyze the Natranaerobius thermophilus JW/NM-WN-LF~T transcriptome,and new transcripts and transcriptional start sites were predicted.The agreement rate of differential genes in the transcriptome and proteome was analyzed.There were 92 up-regulated genes and 108 down-regulated genes.These genes may play an important role in revealing the adaptation mechanisms of extremophiles to the environment,laying the foundation for further research.