Whole Genome Sequencing Of Methylosinus Sp.PRM1 And Comparative Analysis Of Genomes Associated With Plant Interactions

Methanotrophs are a type of methylotrophic bacteria that use methane as the sole carbon source and energy for growth,and play an important role in reducing methane emissions from wetlands.Recent studies have shown that Methylosinus in root tissues of rice and Phragmites australis plays a dominant role in nitrogen fixation and were loacalized around the vascular cylinder in the root tissues.However,the relationship between methanotrophs and plants interactions is unclear.Microbes and plants interactions require possession of nitrogen-fixing,secretion system,flagella and chemotaxis-related genes.In this study,physiological and biochemical morphological characteristics,whole genome sequencing and comparative genomic analysis were performed on a Methylosinus sp.strain PRM1 isolated from P.australis root of Hasuhai wetlands in Inner Mongolia to investigate the potential of aerobic methanotrophs to interact with aquatic plants at the gene level..The results are as follows:(1)The strain Methylosinus sp.PRM1 utilizes two carbon sources,methaneand methanol,nitrate and 10 amino acid including L-alanine as nitrogen sources,optimum p H 7,optimum methane concentration 20%,salinity tolerance 0.5%(w/v)Na Cl.The strain had a polar flagellum and fimbriae.(2)The genomic feature of strain PRM1 contained one circular chromosome of4.13 Mb,4 plasmids,and a GC content of 64.98%.A total of 3845 protein coding genes(CDSs),two different 16 S r RNA gene copies and two p MMO enzymes were identified.The complete methane oxidation pathway and methane assimilation of serine cycle were also identified.In addition,complete genome of PRM1 also contained the nitrogen fixation completed gene cluster(nif HDK),Type IV secretion system(T4SS),flagella and chemotaxis related genes.(3)Comparative genomic analysis of 74 strains of methanotrophs showed that all aerobic methanotrophs except the Methylocella possess the particulate methane monooxygenase(p MMO),while the soluble methane monooxygenase(s MMO)predominantly found in Type ? methanotrophs(Methylosinus,Methylocystis and Methylocapsa)and individual Type I methanotrophs;Most(65/74)methanotrophs have a complete gene cluster(nif HKD)encoding denitrogenase;All strains possess Type IV secretion system(T4SS)as main secretion system.Among them,Type?methanotrophs possess conjugation genes trb gene and Type IVb fimbriae,and Type?methanotrophs possess Type IVa fimbriae and Inc F plasmid conjoining Tra genes;In terms of mobility,most strains of all genera except Methylocystis possess flagellar genes,but few methanotrophs with complete chemotactic genes.(4)The genus Methylosinus and Methylocapsa of Type II methanotrophs and thegenus Methylomonas,Methylomicrobium,Methylocaldum,and Methylobacter of Type I methanotrophs possess complete gene clusters to interact with plants and are more likely to establish enteraction with root systems of Phragmites australis or rice.