Comparative Genomics Of New Species And Antagonistic Strains Of Actinomycetes

Actinomycetes are one of the main sources of active natural products,but the traditional mining methods of active products are blind.In order to reduce the occurrence of this situation,genome-guided secondary metabolite mining strategy emerged.With the development of genomics technology,researchers use genomics and comparative genomics analysis to dig up novel secondary metabolites,new antibiotics and new drugs in microorganisms.(1)Comparative genomic analysis of new species of StreptomycesIn this study,30 new species of Streptomyces were used for genomic and comparative genomic analysis.The 5 strains isolated from the silt of the Tailan River had the characteristics of large genome and more CDS and biosynthetic gene clusters,which would provide strain resources for genome mining of new species of Streptomyces.There were 8 strains containing vancomycin resistance genes,among which TRM68295 contained the most vancomycin resistance genes(9),which will provide strong evidence for the study of drug resistance of new species of Streptomyces.The new species of Streptomyces have an open pan-genome,which indicates that the gene pool of new species of Streptomyces has a high diversity.(2)Comparative genomic analysis of new species of rare ActinomycetesIn this study,6 new species of rare actinomycetes were used for genomic and comparative genomic analysis.TRM 64739 had the largest genome size,number of CDS and number of biosynthetic gene clusters.TRM 65233 and TRM 64739,two isolates isolated from desert plants,both contained more than50 biosynthetic gene clusters,which would provide genomic guidance for mining the metabolites of new species of rare actinomycetes.The vancomycin-resistant strains TRM 64739 and TRM 65318 contain 5 and3 vancomycin-resistant genes,respectively,which will provide a theoretical basis for antibiotic tolerance studies of new species of rare actinomyces.(3)Comparative genomic analysis of antagonistic strains of ActinomycetesIn this study,31 existing antagonistic strains of actinomycetes were used for activity verification and genomic and comparative genomic analysis.There were 9 strains with more than 40 gene clusters in the genome of antagonistic strains,among which 4 strains were isolated from the silt of Xinjiang desert environment,and the other 5 strains were isolated from Xinjiang desert plants.These results will provide theoretical basis for understanding the secondary metabolic potential of antagonistic strains and mining new antibiotics.6 strains of Streptomyces albidoflavus and 12 strains of Streptomyces rochei showed differences in antimicrobial activity.Through genomic analysis,it was found that there were differences in genome size,number of CDS,number of r RNA,number of t RNA and biosynthetic gene cluster.The genome of the strains was compared and analyzed,it was found that apart from homologous gene clusters,some strains had unique gene clusters in their genomes.Further studies are needed to verify whether genomic differences and specific gene clusters are related to differences in antimicrobial activity.(4)Polyphasic classification and identification of two new species of ActinomycetesThe optimal growth conditions of strain TRM 68416 were 28?,p H 8.0 and salt concentration 0%.Physiological and biochemical characteristics are no oxidase activity,catalase activity,urease activity,amylase activity,lipase activity,can make nitrate reduction,can make milk peptone,can decompose cellulose,can produce hydrogen sulfide,can not make gelatin liquefied,do not form melanin.The main hydrolytic sugar types of strain TRM 68416 were ribose and glucose;The main amino acid type was LL-DAP;The main types of phospholipids were PG,DPG,PE,PC,PI and PIM;The main fatty acid types are CIS-C_16:1,ISO-C_16:0and C_16:0;The main methyl naphthoquinone types are Mk-9(H₁₀),Mk-9(H₈)and Mk-9(H₆);Genomic(G+C)mol%was 71.43mol%;The DNA-DNA hybridization value with the most similar strains was 23.30%.TRM 68416 was identified as a new species of Streptomyces tailanheensis based on the above characteristics.The optimal growth conditions of strain TRM 65237 were 28?,p H 9.0 and salt concentration 0%.Physiological and biochemical characteristics are no oxidase activity,no urease activity,no amylase activity,no lipase activity,catalase activity,can not liquefy gelatin,do not produce hydrogen sulfide,do not form melanin,can not coagulate milk or peptone,can not decompose cellulose and can make nitrate reduction.The main hydrolytic sugar types of strain TRM 65237 were arabinose and glucose;The main amino acid types were LL-DAP and DD-DAP;The main types of phospholipids are PG,DPG,PE,PC,PME,PI and PIM;The main fatty acid types are methyl-C_18:0,C_16:0,and C_16:1;The main methyl naphthoquinone types are Mk-10(H₄),Mk-7(H₆)and Mk-9(H₁₀);Genomic(G+C)mol%was 67.37mol%;The DNA-DNA hybridization value with the most similar strains was 39.80%.TRM 65237 was identified as a new species of Nocardia peganumharmalg based on the above characteristics.This study existing 36 strains actinomycetes new species in the laboratory and existing antagonistic 31strains of genomics and comparative genomics analysis,looking for new species of actinomycetes novel biosynthesis gene cluster,the activity of strains,the inhibitory action to reveal differences and guide new microbial sources of natural products found that provide important theoretical guidance.