Vibrio casei sp. nov., isolated from the surfaces of two French red smear soft cheeses

Abstract

Three Gram-negative, rod-shaped, catalase-and oxidase-positive, facultatively anaerobic and motile bacteria, strains WS 4538, WS 4539 T and WS 4540, were isolated from the surfaces of two fully ripened French red smear soft cheeses. Based on 16S rRNA gene sequence similarity, all three strains were shown to belong to the genus Vibrio. They are most closely related to Vibrio rumoiensis S-1 T (96.3 % similarity) and Vibrio litoralis MANO22D T (95.9 %). DNA-DNA hybridization confirmed that all three isolates belong to the same species and clearly separated strain WS 4539 T from V. rumoiensis DSM 19141 T (38-42 % relatedness) and V. litoralis DSM 17657 T (28-37 %). In contrast to their nearest relatives, the strains exhibited b-galactosidase and aesculin hydrolase activities. A 14 bp insertion in the 16S rRNA gene sequence forms an elongated structure at helix 10 in the rRNA molecule and provides a tool for PCR-based identification of the novel species. Partial sequences of the housekeeping genes atpA, recA, rpoA and pyrH supported the conclusion that the three isolates constitute a separate species within the genus Vibrio. The name Vibrio casei sp. nov. is proposed for the novel taxon. Strain WS 4539 T (5DSM 22364 T 5LMG 25240 T ; DNA G+C content 41.8 mol%) is the type strain and WS 4540 (5DSM 22378 5LMG 25241) is a reference strain.The family Vibrionaceae (Baumann & Schubert, 1984) belongs to the class Gammaproteobacteria and includes, amongst others, the genera Photobacterium , Salinivibrio (Mellado et al., 1996) and Vibrio. At the time of writing, the genus Vibrio consists of 72 recognized species that form nine phylogenetically distinct clades (Association of Vibrio Biologists; http:// www.vibriobiology.net/). The clearly separated rumoiensis clade consists of Vibrio rumoiensis (Yumoto et al., 1999) and Vibrio litoralis (Nam et al., 2007) and forms a distant lineage within the genus. Micro-organisms belonging to the genus Vibrio are known to live either freely or associated as symbionts with aquatic animals in marine or estuarine waters (Browne-Silva & Nishiguchi, 2008) or as parasites of fish, crustaceans and molluscs (Thompson et al., 2004). Vibrio species have been reported less frequently as members of microbial consortia on cheese surfaces (Feurer et al., 2004), but some studies have suggested that they play a role in the ripening process (ElBaradei et al., 2007).The composition of the surface microbial consortia of two French smear-ripened cheeses, Petit Munster Ermitage and Reflets de France Petit Livarot, was analysed using Fouriertransform infrared (FT-IR) spectroscopy (Kümmerle et al., 1998;Naumann et al., 1991). After 5 days of aerobic incubation at 10-30 u C, isolates were picked randomly from fully grown plate count agar plates, supplemented with 3 % NaCl (PC3+). The cell densities of the surface consortia were 6610 9 c.f.u. ml 21 (Munster) and 4610 10 c.f.u. ml 21 (Livarot). Strains WS 4538 and WS 4539 T were isolated from the Munster cheese at the Fromagerie de l'Ermitage, Bulgnéville, France ...

Facility-Specific “House” Microbiome Drives Microbial Landscapes of Artisan Cheesemaking Plants

“…Using a culture-based approach, Mounier et al (14) detected a similar "house" microbiota in a washed-rind cheesemaking plant, dominated by Debaryomyces hansenii, Corynebacterium spp., and Staphylococcus saprophyticus, suggesting that this same functional community may generalize across facilities producing similar styles of cheese. Several of the halotolerant Gammaproteobacteria detected on aging surfaces and cheeses in this study have been isolated previously from European washed-rind cheeses, including Pseudoalteromonas (50), Halomonas (50)(51)(52)(53), and Vibrio (49,52), so likewise appear to be part of the style-specific microbiome enriched by washed-rind processing techniques and likely play a role in the maturation phenomena of these cheeses. The coryneform Actinobacteria detected on aging-room and cheese surfaces, particularly in facility A, have likewise been isolated from washed-rind cheeses previously, including Brevibacterium (50)(51)(52)54), Corynebacterium (50)(51)(52)54), and Brachybacterium (50,54,55).…”

“…In facility B, Pseuodoalteromonas, Vibrio, and Vibrionaceae were similarly abundant on aging-room and cheese surfaces, illustrating a close relationship between environmental and cheese surface microbiota. Vibrio casei, the closest match for the Vibrionaceae sequences, was originally isolated from a French washed-rind cheese surface (49), and its appearance here suggests a wider association with cheeses of this type. These and other halotolerant Gammaproteobacteria (especially Pseudoalteromonas) dominated the washed-rind maturation room surfaces in facility B in lieu of Brevibacterium and Staphylococcus, both of which dominated these surfaces and cheese surfaces in facility A.…”

“…The Vibrio and Vibrionaceae sequences were most closely related to Vibrio casei, as determined by a manual NCBI BLAST search (data not shown). V. casei is a recently described species originally isolated from French washed-rind cheeses (49).…”

A standard bacterial isolate set for research on contemporary dairy spoilage

“…The isolate set also includes an isolate of Vibrio casei. This recently identified species was shown to be commonly identified in raw-milk cheese samples (Bleicher et al, 2010;Wolfe et al, 2014).…”

Temporal and Spatial Differences in Microbial Composition during the Manufacture of a Continental-Type Cheese

“…Vibrio and Pseudoalteromonas are marine-associated, halophilic genera and therefore may have gained access to the cheese via the brining process. While the significance of the presence of these populations is not yet clear, particularly at the levels present in the cheese, they may play a role in ripening (38,49,54). Psychrotrophic bacteria, including Psychrobacter and Pseudomonas, have previously been isolated from a variety of cheeses as well as raw milk and are particularly adapted to lowtemperature milk storage conditions (49,55,56).…”