Isolation And Diversity Of Culturable Actinobacteria From The Western Pacific

Actinomycetes are one of the most attractive sources of antibiotics.Marineenvironments,especially sediments,are rich sources of antinomycetes that providemany bioactive compounds,primarily antibiotics.The goal of this study was toinvestigate the diversity of cultivable actinomycetes and their potential to produceantibiotics from sediments and water collected from the western Pacific.Strains of pure actinomycetes were isolated by six modified actinomycetesisolation agar at the sampling site and a small part of isolation of actinomycetes strainwas obtained by eight separation medium with three preparation method.And thefirst and third step of DDC treatment liquid separation performed good,glycerolarginine and raffinose-histidine both were the excellent medias.The actinomyceteswere identified on the basis of morphological characteristics and molecular biologicalmethods.A total of80strains of actinomycetes wewe isolated,belongs toCellulosimicrobium(4),Isoptericola(4),Cellulomonas(3),Ornithinimicrobium(3),Janibacter(1),Curtobacterium(1),Leucobacter(1),Yonghaparkia(1),Agrococcus(1),Microbacterium(5),Brachybacterium(4),Micrococcus(3),Nesterenkonia(4),Brevibacterium(4),Streptomyces(17),Nocardiopsis(4),Nocardioides(2),Dietzia(8),Rhodococcus(9)and Gordonia(1). Based on16S rRNA gene sequence data and phylogenetic analysis,indicated thatfive strains are are likely to represent new taxa.Using a sequence identity value of≥97%,the80isolates grouped into32operational taxonomic units,the representative strains screening of biological activityand functional gene amplification.Gene function test results showed PKSI,PKSII threefunctions and NRPS gene in the marine actinomycetes widespread,which PKSI type offunctional genes amplified positive rate of39.4%,mainly inBrevibacterium,Streptomyces,and Rhodococcus genus,PKSII type function the positiveamplification of the gene was27.3%,mainly distributed inBrevibacterium,Nocardiopsis,NRPS gene function type positive amplification rate of57.6%,mainly in Rhodococcus,Streptomyces,Nocardiopsis and Brachybacteriumgenus,what’s more,two actinomycetes containing three functional genes,belonging togenus Brevibacterium and Nocardiopsis. TLC chromatography results showed thatthere are18bacteria fermentation extract contains many components,with11strains ofdifferent genera iodine staining reaction was active,eight different genera8bacteria staining reaction in sulfuric acid was active,there are five in the Dragendorff reactionactive,wherein the two Dietzia genus bacteria are layered in this reaction more,inaddition,two strains of bacteria were very active in the three kinds of stainingreaction,they belong Cellulomonas,Streptomyces spp. Antibacterial test results showthat two-thirds of the experimental strains produced inhibition zone,where there are11species Bacillus subtilis producesantagonism,Brachybacterium,Nesterenkonia,Nocardiopsis and was particularly activein the genus Rhodococcus,there are eight genus Staphylococcus aureus produceinhibitory effects,which Dietzia and Streptomyces strains produce more inhibitoryeffect is,in addition,there are five different genera of five strains of Vibrio alginolyticusantagonism,in general,be able to Bacillus subtilis strains produce antagonism more,lessinhibition Alginolyticus strains.In summary,the western Pacific marine actinomycetes were isolated and screenedto obtained a high diversity of strains of actinomycetes,which enriched the WesternPacific actinomycetes strains repository,some with good antibacterial activity and lessactinomycetes high abundance of functional genes will provide the basis for thesubsequent separation of active compounds for marine actinomycetes resources to laythe foundation for further development and utilization.