Emended Descriptions of Lactobacillus sake (Katagiri, Kitahara, and Fukami) and Lactobacillus curvatus (Abo-Elnaga and Kandler): Numerical Classification Revealed by Protein Figerprinting and Identification Based on Biochemical Patterns and DNA-DNA Hybridizations

Abstract

A former subgenus of the genus Lactobacillus, "Streptobacterium," comprises a wide range of species, including the so-called "atypical streptobacteria," which includes the Lactobacillus sake-Lactobacillus curvatus group. Various identification systems and differentiation criteria for L. sake and L. curvatus have been described previously and are well established. The phenotypic diversity within these two species was the reason for comparing phenotypic variations with DNA homology data. Previously described biotypes of L. sake (Katagiri, Kitahara, and Fukami) and L. curvatus (Abo-Elnaga and Kandler) were the basis for selecting strains. Strains of all known biotypes of these species were examined to determine their biochemical reactions, their physiological growth characteristics, their total soluble protein contents as determined by a pattern analysis in which native polyacrylamide gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with colloidal Coomassie blue and silver diamine staining were used, and their levels of DNA homology as determined by DNA-DNA hybridization experiments. All of the phenotypic analyses revealed a diversity within the taxa, whereas the DNA-DNA hybridization analysis revealed that the level of genomic homogeneity within each species was relatively high. The phenotypic diversity and genomic homogeneity which we observed allowed us to describe subgroups of L. sake and L. curvatus. The descriptions of L. sake and L. curvatus are emended accordingly. These subgroups which we describe may be the basis for defining subspecies within these two species.The facultatively heterofermentative lactobacilli comprise a wide range of species, including species and subspecies of technological and clinical interest, such as Lactobacillus casei, Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus paracasei subspecies. The so-called "atypical streptobacteria" (13, 18, 19, 34,44), which are significant spoilage bacteria, are of special interest and occur in naturally or artificially fermented meat. The habitats of Lactobacillus sake and Lactobacillus cuwatus are very diverse. These organisms are important in the production of fermented plant material (silage, sauerkraut, mixed pickles, etc.) and in the spoilage of plant material as well. They also occur in beverages (e.g., beer) and even in manure (14, 22). L. sake was first isolated from sake (rice wine) starter (22). Our strain collection also includes L. sake strains of human origin, a habitat not described previously for this species (Table 1). These bacteria have been called atypical streptobacteria compared with the "streptobacteria," a term used in classical and descriptive taxonomy (31) which is no longer used in genomically based taxonomy (46). The ability to grow at 2°C and pH 3.9 was recognized as a main criterion for differentiation. Table 2 shows other distinguishing characteristics that are based on morphological and physiological data (31, 36, 37 two species are well established, the phenotypic d...

Lactobacillus curvatus subsp. melibiosus is a later synonym of Lactobacillus sakei subsp. carnosus

“…The G+C content of all strains varied around the value 42?5± 0?3 mol%, but strain YMRS3a gave a value of 40?5 mol%. These values are in agreement with the previously described values, generally ranging from 42 to 44 mol% (Hammes & Vogel, 1995 Klein et al (1996). However, the reassociation values obtained for L. curvatus subsp.…”

“…Whereas the former allowed a clear separation between the L. sakei subspecies sakei and carnosus (Fig. 1), confirming data reported by Klein et al (1996), the latter did not (see supplementary material in IJSEM Online).…”

“…carnosus. This similarity in whole-cell protein profiles was not reported by Klein et al (1996), although the five L. sakei subsp. carnosus reference strains and the L. curvatus subsp.…”

“…melibiosus type strain were included in both studies. Klein et al (1996), however, decided to publish the crude, native whole-cell protein profiles in a one dendrogram, whereas more sophisticated dendrograms derived from silver diamine and Coomassie brilliant blue-stained polyacrylamide gels were both separated into two figures, one comprising the presumed L. curvatus subspecies and the other the L. sakei subspecies. Therefore, the high degree of similarity of the patterns of L. curvatus subsp.…”

Characterisation of lactic acid bacteria from spoiled, vacuum-packaged, cold-smoked rainbow trout using ribotyping

“…curvatus species. However, the studies performed by Klein et al (1996) and Torriani et al (1996) showed different reassociation values and warrant this. More studies must be performed by means of DNA-DNA reassociation with a larger number of strains from this cluster in order to clarify the status of our strains.…”