| Termites are old social insects,which can degrade lingocellulose efficiently.They distribute widely in tropical and subtropical regions.The ability of lingocellulose degradation is closely related to their intestinal symbiotic microorganisms.The relationship between termites and their intestinal microbiota has been always a hotspot in the research about termites.The diversity and quantity of intestinal microbes of different termites are very different depending on the type of species,food habits,and other characteristics of termites.In this paper,we report two bacterial strains isolated from a lower wood-fooding termite,Reticulitermes aculabialis and a higher wood-fooding termite,Nasutitermes hainanensis which are named Ra1 and YH11,respectively.We characterize these two strains by polyphasic taxonomy approach.It is significant not only for the enrichment of new bacterial resources in nature,but also for the understanding of symbiotic mechanisms between intestinal microorganisms and their termite hosts.The main research results are as following:1.Characterization of strain Ra1 with polyphasic taxonomy approachCells of Ra1 were Gram-negative,aerobic,non-spore-forming,non-motile rods(approximately 0.5 ?m in diameter,0.8-1.8 ?m in length).Colonies were circular,transparent,smooth,and non-yellow-pigmented on TSB agar.Phylogenetic analysis of 16S rRNA gene sequences showed that strain Ra1 was closely related to Chryseobacterium rigui JCM 18078T with sequence similarity of 96.7%.The optimum growth temperature was 30?,and the optimum growth pH was 8.0.Strain Ra1 was not tolerant to NaCl.Oxidase and catalase were positive.Starch,casein,Tween 80 was not hydrolyzed.Hydrogen sulfide and indole were produced.Nitrate could not be reduced to nitrite.Glucose,mannose and some other carbonhydrates could be assimilated.Acid was produced from D-xylose,D-glucose,D-fructose.In addition,esterase lipase(C8),trypsin,a-chymotrypsin and some other enzymes are positive.The major components of cellular fatty acids were iso-C15:0,iso-C17:0 3-OH.In addition to phosphatidylethanolamine,the polar lipid profile contains three unknown aminolipids,one unknown phospholipid and one unknown lipid.The major polyamine was sym-homospermidine.The respiratory quinone was MK-6.The genomic DNA G+C content of the type strain was 39.9 mol%.Based on these results,it is concluded that strain Ra1T represents a novel species of the genus Chryseobacterium,for which the name Chryseobacterium reticulitermitis sp.nov.is proposed,the type strain is Ra1T(= CCTCC AB 2015431T = KCTC 52230T).2.Characterization of strain YH11 with polyphasic taxonomy approachCells of YH11 were Gram-negative,facultatively anaerobic,non-spore-forming,non-motile rods(approximately 1.0-1.4 ?m × 0.4-0.6 ?m).Colonies were yellow,circular,and smooth with entire edge on TSB agar.Phylogenetic analysis of 16S rRNA gene sequences showed that strain YH11 was closely related to Propioniciclava tarda JCM 15804T with sequence similarity of 92.1%.The optimum growth temperature was 30?,the optimum growth pH was 8.0,and the optimum growth concentration of NaCl was 1%.Oxidase was negative,while catalase was positive.Hydrogen sulfide was produced,indole was not produced.Nitrate was reduced to nitrite.Casein,Tween 80 was not hydrolyzed,while starch could be hydrolyzed.Glucose,mannitol could be assimilated.Acid was produced from D-xylose,D-galactose,D-glucose,D-fructose and some other substrates.p-galactosidase,?-glucosidase,?-glucosidase were positive.The respiratory quinone was MK-9;and the polar lipid profile contains GL(glycolipid),PL(phospholipid),DPG(diphosphatidyl glycerol).The major components of cellular fatty acid was iso-C15:0 anteiso,and some other components,like C17:0,iso-C14:0.The genomic DNA G+C content of the type strain was 59.5 mol%.Based on these results,it is concluded that strain YH11T represents a novel species of the genus Propioniciclava,for which Propioniciclava nasutitermitis sp.nov.is proposed,the type strain is YH11T(= CGMCC 1.16316T =KCTC 15649T). |
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