Polyphasic Taxonomy And Genome Analyses Of The Multiple Heavy Metal Resistant Strain Pseudaminobacter Manganicus JH-7~T

In this study,a Gram-staining-negative,aerobic,non-motile,capsule-forming and rod-shaped bacterium,designated JH-7~T,was isolated from sludge of a manganese mine sludge.Interestingly,strain JH-7~T shows multiple heavy metals multiple and antibiotics resistances,and it could also grow in 6% NaCl.Thus,strain JH-7~T shows a great potential in bioremediation of heavy metal contaminated and salt environment.The 16 S rRNA gene sequence of strain JH-7~T showed highest similarities to Pseudaminobacter salicylatoxidans BN12T(97.4%),Mesorhizobium thiogangeticum SJTT(97.0%)and Pseudaminobacter defluvii THI 051T(96.5%).Phylogenetic trees clustered strain JH-7~T together with P.salicylatoxidans BN12 T and P.defluvii THI 051 T.The DNA-DNA hybridization values between strain JH-7~T and P.salicylatoxidans DSM 6986 T and between strain JH-7~T and M.thiogangeticum DSM 17097 T were 34.8% and 20.1%,respectively.The major fatty acids of strain JH-7~T(> 10%)were C18:1 ω7c,C19:0 cyclo ω8c and C16:0.The genomic DNA G+C content was 61.6 mol%.The polyamines of strain JH-7~T were sym-homospermidine(83%)and putrescine(17%),and the respiratory quinone was ubiquinone-10.The major polar lipids were phosphatidylmonomethylethanolamine,diphosphatidylglycerol,phosphatidylglycerol,phosphatidylcholine,two unidentified aminolipids and two unidentified lipids.Compared to the Pseudaminobacter and Mesorhizobium members,strain JH-7~T showed some unique physiological and biochemical characters,such as negative in H2 S production,hydrolysis of Tween 40 and Tween 60,esterase lipase(C8)activity and assimilation of D-ribose,and positive in acid production from D-galactose and assimilation of D-fructose.On the basis of the polyphasic taxonomic analysis,strain JH-7~T was considered to represent a novel species of the genus Pseudaminobacter,for which the name Pseudaminobacter manganicus sp.nov.is proposed.In order to further identify the taxonomic status of strain JH-7~T from the genome level,and to explore its basic of genomic in multi-heavy metal,salt tolerance and antibiotic resistance,we reported the draft genomic sequence ofstrain JH-7~T.Strain JH-7~T has a 4,842,937 bp genome size with a G+C content of 61.2%,containing 4504 protein-coding genes and 71 RNA genes.The comparative genomics analysis shows that there were much similarity in genome size,the content of G+C and protein CDSs number between strain JH-7~T and strain Pseudaminobacter salicylatoxidans KCT001.And the ANI number(75.9%)show that strain JH-7~T is a new species and separate from strain KCT001.There are a lot of genes related to resistance of strain JH-7~T in its genome,Most of these genes encode transporters and efflux proteins,which could maintain the balance of intracellular substances,allowing strains to couple complex and harmful environments.For example,MntH is a divalent metal cation transporter of broad substrate specificity which selectively uptake of Mn2+ and other divalent metals,and reducing intracellular accumulation.The classification of glycosyl hydrolases shows that the strains possess multiple peptidoglycan hydrolases which provides potential application.In conclusion,this study extended the understanding of the microbial population structure of manganese mine area,and supplemented the diversity of the genus Pseudaminobacter.In addition,it provides bacterial and genomic resources for the application in the remediation of heavy metal pollution.