E-Book Overview
Article. Published in Journal of Applied Bacteriology. - 1993. - № 75. - p.595-603.
Taxonomic studies were performed on some unknown Leuconostoc-like organisms from fermented Greek sausage. Comparative 16s rRNA sequence analysis showed the unidentified organisms represent a new line within the Leuconostoc pararnesenteroides group of species. On the basis of the results of this and earlier phylogenetic investigations, it is proposed that Leuconostoc paramesenteroides and related species be reclassified in a new genus Weissella. In addition a new species, Weissella hellenica, is proposed for the isolates from fermented sausage.<strong>Introduction. <strong>Materials and methods: Bacterial strains, Biochemical tests, DNA base composition, 16s rRNA gene sequence determination and analysis, Oligonucleotide probe hybridizations. <strong>Results and discussion: Description of Weisseiia gen. nov., Differentiation of the genus Weissella from the other lactic acid taxa, Differentlation of Welssella hellenlca from other Welssella species. <strong>Acknowledgements. <strong>References.
E-Book Content
Journal of Applied Bacteriology 1993,75,595-603
Taxonomic studies on some leuconostoc-like organisms from fermented sausages: description of a new genus Weissella for the Leuconostoc paramesenteroides group of species M.D. Collins, J. Samelisl, J. Metaxopoulos’ and S. Wallbanks AFRC Institute of Food Research, Department of Microbiology, Reading Laboratory, Reading, UK and ’Agricultural University of Athens, Department of Food Science and Technology, Athens, Greece 4509/03/93:accepted 3 July 1993 M.D. COLLINS, J. S A M E L I S , J. M E T A X O P O U L O S A N D s. W A L L B A N K S . 1993. Taxonomic studies were performed o n some unknown Leuconostoc-like organisms from fermented Greek sausage. Comparative 16s r R N A sequence analysis showed the unidentified organisms represent a new line within t h e Leuconostoc pararnesenteroides group of species. O n t h e basis of the results of this and earlier phylogenetic investigations, it is proposed that Leuconostoc paramesenteroides and related species be reclassified in a new genus Weissella. I n addition a new species, Weissella hellenica, is proposed for t h e isolates from fermented sausage.
INTRODUCTION
Leuconstocs are a diverse group of Gram-positive catalasenegative cocci which share many characteristics with the genus Lactobacillus and other ‘lactic acid bacteria’. Apart from their typically irregular coccoid morphology, leuconostocs are distinguished from gas-forming heterofermentative lactobacilli primarily by their inability to produce ammonia from arginine and the formation of only D( -)-lactate from glucose (Garvie 1986). Some atypical species of heterofermentative lactobacilli, however, e.g. Lactobacillus viridescens and Lact. fructosus do not deaminate arginine and form predominantly D( -)-lactate. The reliable differentiation of leuconostocs from such heterofermentative lactobacilli by phenotypic criteria is currently very difficult. Furthermore, recent molecular systematic investigations have revealed these taxa are phylogenetically intermixed, In particular, 16s rRNA sequencing studies show leuconostocs comprise three distinct genetic lines : the genus Leuconostoc sensu stricto, the Leuconostoc paramesenteroides group (which includes the atypical lactobacilli Lact. confusus, Lact. minor, Lact. kandleri, Lact. halotolerans and Lact. viridescens) and the species Leuc. oenos (Yang and Woese 1989; Martinez-Murcia and Collins 1990, 1991; Collins et al. 1991). In the course of a survey of the lactic acid flora of dry naturally-fermented Greek sausage, we isolated a group of Leuconostoc-like organisms. The sausage isolates resembled leuconostocs in producing D( -)-lactic Correspondence