Marinilactibacillus psychrotolerans gen. nov., sp. nov., a halophilic and alkaliphilic marine lactic acid bacterium isolated from marine organisms in temperate and subtropical areas of Japan A novel marine lactic acid rod bacterium has been described for eight strains isolated from living and decomposing marine organisms collected from temperate and subtropical areas of Japan. The isolates were Gram-positive, catalase-negative, non-sporulating and motile with peritrichous flagella. They were slightly halophilic, highly halotolerant and alkaliphilic; the optimum NaCl concentration for growth was 2?0-3?75 % (w/v) with a range from 0 to 17?0-20?5 % (depending on the strain); the optimum pH was between 8?0 and 9?5 with a range from 6?0 to 10?0. They were psychrotolerant, growing well at 21?8˚C with a maximum at 40-45˚C and the optimum at 37-40˚C. Lactate yields were 87-100 % per consumed glucose; the residual products were formate, acetate and ethanol with a molar ratio of approximately 2 : 1 : 1. The product composition was markedly affected by the pH of fermentation medium; at higher pH, the yield of lactate decreased (60-65 % at pH 9?0) and that of other products increased conversely. The cell-wall peptidoglycan type was type A4b, Orn-D-Glu, whereas that of the genus Alkalibacterium, the phylogenetically closest lactic acid bacterium, was type A4b, Orn-D-Asp. The major cellular fatty acids were C16 : 0, C16 : 1D9, C18 : 0 and C18 : 1D9 (oleic acid). The G+C content of the DNA was 34?6-36?2 mol%. The eight isolates were phenotypically homogeneous and formed a single genomic species. The 16S rRNA gene sequence analysis indicated that the isolates constituted an independent phylogenetic lineage within the radiation of lactic acid bacteria with 96?2 % similarity to the genus Alkalibacterium. The secondary structure and the nucleotide sequence of the V6 region of the 16S rRNA were characteristic of the organism among other related lactic acid genera. On the bases of phenotypic and phylogenetic distinctness, the organism was proposed to belong to a new genus and species, Marinilactibacillus psychrotolerans gen. nov., sp. nov. The type strain, M13-2 T (G+C=36?2 mol%), has been deposited in the IAM, NBRC, NCIMB and NRIC culture collections as IAM 14980

Eleven novel strains of marine-inhabiting lactic acid bacteria that were isolated from living and decaying marine organisms collected from a temperate area of Japan are described. The isolates were motile with peritrichous flagella and non-sporulating. They lacked catalase, quinones and cytochromes. Fermentation products from glucose were lactate, formate, acetate and ethanol. Lactate yield as percentage conversion from glucose was affected by the pH of the fermentation medium: ∼55 % at the optimal growth pH of 8·0, greater than ∼70 % at pH 7·0 and less than ∼30 % at pH 9·0. The molar ratio of the other three products was the same at each cultivation pH, approximately 2 : 1 : 1. Carbohydrates and related compounds were aerobically metabolized to acetate and pyruvate as well as lactate. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. The optimum NaCl concentration for growth was 2·0–3·0 % (w/v), with a range of 0–25·5 %. The optimum pH for growth was 8·0–9·5, with a range of 6·0–10·0. The G+C content of the DNA was 38·5–40·7 mol%. The isolates constituted two genomic species (DNA–DNA relatedness of less than 41 %) each characterized by sugar fermentation profiles. The cell-wall peptidoglycan of both phenotypes contained meso-diaminopimelic acid. The major cellular fatty acids were C16 : 0 and a-C13 : 0. Comparative sequence analysis of the 16S rRNA genes revealed that these isolates represent novel species constituting a phylogenetic unit outside the radiation of typical lactic acid bacteria and an independent line of descent within the group composed of the halophilic/halotolerant/alkaliphilic and/or alkalitolerant species in Bacillus rRNA group 1, with 94·8–95·1 % similarity to the genus Paraliobacillus, 93·7–94·1 % to the genus Gracilibacillus and 93·8–94·2 % to Virgibacillus marismortui. On the basis of possession of physiological and biochemical characteristics common to typical lactic acid bacteria within Bacillus rRNA group 1, chemotaxonomic characteristics and phylogenetic independence, a new genus and two species, Halolactibacillus halophilus gen. nov., sp. nov. and Halolatibacillus miurensis sp. nov., are proposed. The type strains are Halolactibacillus halophilus M2-2T (=DSM 17073T=IAM 15242T=NBRC 100868T=NRIC 0628T) (G+C content 40·2 mol%) and Halolactibacillus miurensis M23-1T (=DSM 17074T=IAM 15247T=NBRC 100873T=NRIC 0633T) (G+C content 38·5 mol%).

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Two novel strains of marine lactic acid bacteria, isolated from decaying marine algae collected from a subtropical area of Japan, are described. The isolates, designated O24-2 T and O25-2,were Gram-positive, non-sporulating and non-motile. They lacked catalase and quinones. Under anaerobic cultivation conditions, lactate was produced from glucose with the production of formate, acetate and ethanol in a molar ratio of approximately 2 : 1 : 1. Under aerobic cultivation conditions, acetate and lactate were produced from carbohydrates and related compounds. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. They were able to grow in 0-17.0 % (w/v) NaCl, with optimum growth of strains O24-2 T and O25-2 at 1.0-3.0 and 1.0-2.0 % (w/v) NaCl, respectively. Growth of strain O24-2 T was observed at pH 7.5-9.5, with optimum growth at pH 8.0-8.5. Comparative 16S rRNA gene sequence analysis revealed that the isolates occupied a phylogenetic position within the genus Alkalibacterium, showing highest similarity (99.6 %) to Alkalibacterium putridalgicola T129-2-1 T . Although sequence similarity was high, the DNA-DNA relatedness value between strain O24-2 T and A. putridalgicola T129-2-1 T was 27 %, indicating that they are members of distinct species. The DNA G+C contents of O24-2 T and O25-2 were 43.7 and 44.4 mol%, respectively, and DNA-DNA relatedness between the isolates was 89 %. The cell-wall peptidoglycan was type A4b, Orn-D-Asp. The major cellular fatty acid components were C 14 : 0 , C 16 : 0 and C 16 : 1 v9c. Based on phenotypic characteristics and genetic distinctiveness, the isolates were classified as representatives of a novel species within the genus Alkalibacterium, for which the name Alkalibacterium subtropicum sp. nov. is proposed; the type strain is O24-2 T (5DSM 23664 T 5NBRC 107172 T ).