Classification And Identification Of One Facultatively Alkaliphilic Species Isolated From A Daqu Sample Based On Polyphasic Taxonmy

China is renowned for its traditional liquor,which is special in the use of a kind of distiller's yeast called Daqu.There is a wide variety of microorganisms contained in Daqu that bring saccharification,fermentation and flavoring substances to the traditional liquor.It contributed to further analysis Daqu affected the yield,even the quality of liquor by studying microorganisms contained in Daqu.The aims of this study is to identify a new facultatively alkaliphilic strain DL503 belonging to Franconibacter which isolated from a Daqu sample in Mao-Tai Town by polyphasic taxonomy.Strain DL503 is a Gram-stain-negative,facultatively anaerobic,non-sporulating,motile and coccoid-rod-shaped bacterium,with 1.8².6?m body length and 0.6⁰.8?m body depth.Strain DL503 has yellow round colonies with ridgy center,neat edges,opaque and smooth surface.Comparative analysis of the 16S rRNA gene sequence shows that the isolate belongs to the genus Franconibacter,showing highest levels of similarity with respect to Franconibacter pulveris JCM 16471^T?98.94%?and Franconibacter helveticus DSM 18396^T?98.39%?.Strain DL503 is a facultatively alkaliphilic species,which optimal growth occurs at37°C,pH 7.0 and 1.5%NaCl.Strain DL503 could take advantage of 30 kinds of difference carbons for fermentation.And is sensitive to antibiotics,including Kanamycin,Chloramphenicol,Neomycin,Erythromycin,Cephalothin,Rifampicin,Penicillin,Gentamicin,Ampicillin,Streptomycin and Novobiocin.The predominant ubiquinone of the strain DL503is Q-8,and the major polar lipid profile consists of a mixture of phosphatidylethanolamine,phosphatidylglycerol and diphosphatidylglycerol.The primary fatty acids are C_16:0,C_17:0cyclo,C_16:1?7c/C_16:1?6c,C_17:1 iso I/C_17:1 anteiso B and C_18:1?7c/C_18:1?6c.The DNA G+C content is 53.3 mol%and the DNA-DNA relatedness values between strain DL503 and its close relatives including F.pulveris JCM 16471^T and F.helveticus DSM 18396^T are 51.5±0.5%and 49.9±0.6%.In summary,strain DL503 represents a novel species of the genus Franconibacter,for which the name Franconibacter daqus sp.nov.is proposed.