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WeissellaRANK: GenusTAXONOMY: Bacteria -> Terrabacteria group -> Firmicutes -> Bacilli -> Lactobacillales -> Leuconostocaceae -> Weissella OVERVIEW: 'Weissella' is a genus of Gram-positive bacteria, placed within the family Leuconostocaceae, and formerly considered species of the Leuconostoc paramesenteroides group. The morphology of Weissella species varies from spherical or lenticular cells to irregular rods. The description for the genus is as published by Collins et al. (1993). The cells are either short rods with rounded tapered ends (see Figure 120 for Weissella cibaria) or ovoid and occur in pairs or in short chains. A tendency toward pleomorphism may be found for strains in species such as Weissella minor (see Figure 121). Gram-stain-positive, nonmotile, and asporogenous. Chemo-organotrophic, facultatively anaerobic, catalase-negative, and devoid of cytochromes. Obligately fermentative chemo-organotrophs; ferment glucose heterofermentatively and have complex nutritional requirements. The genus Weissella belongs to lactic acid bacteria (LAB) because of their metabolism and phylogenetic position. Carbohydrate fermentation via the hexose-monophosphate and the phosphoketolase pathways. End products of glucose fermentation are CO2, ethanol, and/or acetate. The configuration of lactic acid is either dl- or d(−), depending on the species. Amino acids, peptides, fermentable carbohydrates, fatty acids, nucleic acids, and vitamins are generally required for growth. Biotin, nicotine, thiamine, and pantothenic acid or its derivatives are required by all strains. Arginine is not hydrolyzed by all species. Growth occurs at 15 °C, with some species growing at 42–45 °C. Cell-wall peptidoglycan is based on lysine as diamino acid, and, with the exception of Weissella kandleri, all contain alanine or alanine and serine in the interpeptide bridge. In addition, the interpeptide bridge of Weissella kandleri (Lys–l-Ala–Gly–l-Ala2) contains glycine (Holzapfel and van Wyk, 1 9 8 2). The phenotypic characteristics of Weissella spp. are listed in Table 128. DNA G+C content (mol%): 37–47 (Tm and Bd). Type species: Weissella viridescens This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072]
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