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

Vibrio ulleungensis sp. nov., isolated from Mytilus coruscus

A Gram-stain-negative, rod-shaped, motile via polar flagellum, facultatively aerobic, light-yellow, bacterium (designated 188UL20-2^T) was isolated from a mussel sample of Mytilus coruscus collected on Ulleung Island, Ulleung-gun, Gyeongsangbuk-do, Republic of Korea. On the basis of 16S rRNA gene sequencing results, strain 188UL20-2^T clustered with species of the genus Vibrio and appeared closely related to Vibrio marisflavi DSM 23086^T (96.59%), Vibrio variabilis DSM 26147^T (96.57%), Vibrio penaeicida DSM 14398^T (96.37%) and Vibrio litoralis DSM 17657^T (95.97%). The average nucleotide identity and digital DNA-DNA hybridization values between strain 188UL20-2^T and its closest related strain were 71.3 and 16.4%, indicating that 188UL20-2^T represents a novel species of the genus Vibrio. Growth occurred at 18-37 °C on MA medium in the presence of 1-4% NaCl (w/v) and at pH 5.0-10.0. The DNA G+C content of the genomic DNA was 45.4 mol%, and ubiquinone-8 (Q-8) was the major respiratory quinone. The major cellular fatty acids (>5%) were C_16:1 ω6c and/or C_16:1 ω7c (summed feature 3), C_18:1 ω7c and/or C_18:1 ω6c (summed feature 8), C_16:0, C_16:0 iso, C_14:0, C_14:0 iso and C_12:0. The polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids, unidentified aminophospholipid, unidentified glycolipid and seven unidentified lipids. Physiological and biochemical characteristics indicated that strain 188UL20-2^T represents a novel species of the genus Vibrio, for which the name Vibrio ulleungensis sp. nov. is proposed. The type strain is 188UL20-2^T (=KACC 22258^T=LMG 32202^T).

Vibrio algicola sp. nov., isolated from the surface of coralline algae

A Gram-stain-negative, oxidase- and catalase-positive, facultative anaerobic and rod-shaped bacterium, designated strain SM1977^T, was isolated from the surface of coralline algae collected from the intertidal zone at Qingdao, PR China. The strain grew at 10-35 °C, pH 4.5-8.5 and with 1-8.5% (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed Tween 20 and DNA. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SM1977^T was affiliated with the genus Vibrio, having the highest sequence similarity (97.6 %) to the type strain of Vibrio casei, followed by those of another five species (95.6-97.6 %) in the Rumoiensis clade of the genus Vibrio. However, the in silico DNA-DNA hybridization (75.3-75.9 %) and average nucleotide identity (21.6-22.8 %) values of SM1977^T against these close relatives were all below the corresponding thresholds to discriminate bacterial species. The major fatty acids were summed feature 3 (C_16:1  ω7c and/or C_16:1  ω6c), C_16:0 and summed feature 8 (C_18:1  ω6c and /or C_18:1  ω7c). The predominant polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The sole respiratory quinone was Q-8. The genomic DNA G+C content of strain SM1977^T, determined from the obtained whole genomic sequence, was 42.3 mol%. On the basis of the polyphasic results obtained in this study, strain SM1977^T is considered to represent a novel species within the genus Vibrio, for which the name Vibrio algicola sp. nov. is proposed. The type strain is SM1977^T (=MCCC 1K04351^T=KCTC 72847^T).

Genomic characterization of closely related species in the Rumoiensis clade infers ecogenomic signatures to non-marine environments

Members of the family Vibrionaceae are generally found in marine and brackish environments, playing important roles in nutrient cycling. The Rumoiensis clade is an unconventional group in the genus Vibrio, currently comprising six species from different origins including two species isolated from non-marine environments. In this study, we performed comparative genome analysis of all six species in the clade using their complete genome sequences. We found that two non-marine species, Vibrio casei and Vibrio gangliei, lacked the genes responsible for algal polysaccharide degradation, while a number of glycoside hydrolase genes were enriched in these two species. Expansion of insertion sequences was observed in V. casei and Vibrio rumoiensis, which suggests ongoing genomic changes associated with niche adaptations. The genes responsible for the metabolism of glucosylglycerate, a compound known to play a role as compatible solutes under nitrogen limitation, were conserved across the clade. These characteristics, along with genes encoding species-specific functions, may reflect the habit expansion which has led to the current distribution of Rumoiensis clade species. Genome analysis of all species in a single clade give us valuable insights into the genomic background of the Rumoiensis clade species and emphasize the genomic diversity and versatility of Vibrionaceae.

Vibrio fujianensis sp. nov., isolated from aquaculture water

A Gram-stain-negative, facultatively anaerobic strain, designated FJ201301^T, was isolated from aquaculture water collected from Fujian province, China. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain FJ201301^T belonged to the genus Vibrio, formed a distinct cluster with Vibriocincinnatiensis ATCC 35912^T and shared the highest similarity with Vibriosalilacus CGMCC 1.12427^T. A 15 bp insertion found in the 16S rRNA gene was a significant marker that distinguished strain FJ201301^T from several phylogenetic neighbours (e.g. V. cincinnatiensis). Multilocus sequence analysis of eight genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA; concatenated 4135 bp sequence) showed that, forming a long and independent phylogenetic branch, strain FJ201301^T clustered with V. cincinnatiensis ATCC 35912^T, Vibrioinjenensis KCTC 32233^T and Vibriometschnikovii CIP 69.14^T clearly separated from V. salilacus CGMCC 1.12427^T. Furthermore, the highest in silico DNA-DNA hybridization and average nucleotide identity values between strain FJ201301^T and the closest related species were 26.3 and 83.1 % with V. cincinnatiensis ATCC 35912^T, less than the proposed cutoff levels for species delineation, i.e. 70 and 95 %, respectively. Biochemical, sequence and genomic analysis suggested the designation of strain FJ201301^T representing a novel species of the genus Vibrio, for which the name Vibrio fujianensis sp. nov. is proposed. The type strain is FJ201301^T (=DSM 104687^T=CGMCC 1.16099^T).

Fungal networks shape dynamics of bacterial dispersal and community assembly in cheese rind microbiomes

Most studies of bacterial motility have examined small-scale (micrometer–centimeter) cell dispersal in monocultures. However, bacteria live in multispecies communities, where interactions with other microbes may inhibit or facilitate dispersal. Here, we demonstrate that motile bacteria in cheese rind microbiomes use physical networks created by filamentous fungi for dispersal, and that these interactions can shape microbial community structure. Serratia proteamaculans and other motile cheese rind bacteria disperse on fungal networks by swimming in the liquid layers formed on fungal hyphae. RNA-sequencing, transposon mutagenesis, and comparative genomics identify potential genetic mechanisms, including flagella-mediated motility, that control bacterial dispersal on hyphae. By manipulating fungal networks in experimental communities, we demonstrate that fungal-mediated bacterial dispersal can shift cheese rind microbiome composition by promoting the growth of motile over non-motile community members. Our single-cell to whole-community systems approach highlights the interactive dynamics of bacterial motility in multispecies microbiomes.

Interactions with other microbes may inhibit or facilitate the dispersal of bacteria. Here, Zhang et al. use cheese rind microbiomes as a model to show that physical networks created by filamentous fungi can affect the dispersal of motile bacteria and thus shape the diversity of microbial communities.

Vibrio aphrogenes sp. nov., in the Rumoiensis clade isolated from a seaweed

A novel strain Vibrio aphrogenes sp. nov. strain CA-1004^T isolated from the surface of seaweed collected on the coast of Mie Prefecture in 1994 [1] was characterized using polyphasic taxonomy including multilocus sequence analysis (MLSA) and a genome based comparison. Both phylogenetic analyses on the basis of 16S rRNA gene sequences and MLSA based on eight protein-coding genes (gapA, gyrB, ftsZ, mreB, pyrH, recA, rpoA, and topA) showed the strain could be placed in the Rumoiensis clade in the genus Vibrio. Sequence similarities of the 16S rRNA gene and the multilocus genes against the Rumoiensis clade members, V. rumoiensis, V. algivorus, V. casei, and V. litoralis, were low enough to propose V. aphrogenes sp. nov. strain CA-1004^T as a separate species. The experimental DNA-DNA hybridization data also revealed that the strain CA-1004^T was separate from four known Rumoiensis clade species. The G+C content of the V. aphrogenes strain was determined as 42.1% based on the genome sequence. Major traits of the strain were non-motile, halophilic, fermentative, alginolytic, and gas production. A total of 27 traits (motility, growth temperature range, amylase, alginase and lipase productions, and assimilation of 19 carbon compounds) distinguished the strain from the other species in the Rumoiensis clade. The name V. aphrogenes sp. nov. is proposed for this species in the Rumoiensis clade, with CA-1004^T as the type strain (JCM 31643^T = DSM 103759^T).

Vibrio algivorus sp. nov., an alginate- and agarose-assimilating bacterium isolated from the gut flora of a turban shell marine snail

An agarose- and alginate-assimilating, Gram-reaction-negative, non-motile, rod-shaped bacterium, designated strain SA2T, was isolated from the gut of a turban shell sea snail (Turbo cornutus) collected near Noto Peninsula, Ishikawa Prefecture, Japan. The 16S rRNA gene sequence of strain SA2T was 99.59 % identical to that of Vibrio rumoiensis DSM 19141T and 98.19 % identical to that of Vibrio litoralis DSM 17657T. This suggested that strain SA2T could be a subspecies of V. rumoiensis or V. litoralis. However, DNA-DNA hybridization results showed only 37.5 % relatedness to DSM 19141T and 44.7 % relatedness to DSM 17657T, which was far lower than the 70 % widely accepted to define common species. Strain SA2T could assimilate agarose as a sole carbon source, whereas strains DSM 19141T and DSM 17657T could not assimilate it at all. Furthermore, results using API 20NE and API ZYM kits indicated that their enzymic and physiological phenotypes were also different. These results suggested that strain SA2T represented a novel species within the genus Vibrio. The major isoprenoid quinone in SA2T was Q-8, and its major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The major fatty acids were summed feature 3, (comprising C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0, and summed feature 8 (comprising C18 : 1ω6c and/or C18 : 1ω7c). The DNA G+C content of SA2T was 40.7 mol%. The name proposed for this novel species of the genus Vibrio is Vibrio algivorus sp. nov., with the type strain designated SA2T (=DSM 29824T=NBRC 111146T).

A standard bacterial isolate set for research on contemporary dairy spoilage

Food spoilage is an ongoing issue that could be dealt with more efficiently if some standardization and unification was introduced in this field of research. For example, research and development efforts to understand and reduce food spoilage can greatly be enhanced through availability and use of standardized isolate sets. To address this critical issue, we have assembled a standard isolate set of dairy spoilers and other selected nonpathogenic organisms frequently associated with dairy products. This publicly available bacterial set consists of (1) 35 gram-positive isolates including 9 Bacillus and 15 Paenibacillus isolates and (2) 16 gram-negative isolates including 4 Pseudomonas and 8 coliform isolates. The set includes isolates obtained from samples of pasteurized milk (n=43), pasteurized chocolate milk (n=1), raw milk (n=1), cheese (n=2), as well as isolates obtained from samples obtained from dairy-powder production (n=4). Analysis of growth characteristics in skim milk broth identified 16 gram-positive and 13 gram-negative isolates as psychrotolerant. Additional phenotypic characterization of isolates included testing for activity of β-galactosidase and lipolytic and proteolytic enzymes. All groups of isolates included in the isolate set exhibited diversity in growth and enzyme activity. Source data for all isolates in this isolate set are publicly available in the FoodMicrobeTracker database (http://www.foodmicrobetracker.com), which allows for continuous updating of information and advancement of knowledge on dairy-spoilage representatives included in this isolate set. This isolate set along with publicly available isolate data provide a unique resource that will help advance knowledge of dairy-spoilage organisms as well as aid industry in development and validation of new control strategies.

Temporal and spatial differences in microbial composition during the manufacture of a continental-type cheese

We sought to determine if the time, within a production day, that a cheese is manufactured has an influence on the microbial community present within that cheese. To facilitate this, 16S rRNA amplicon sequencing was used to elucidate the microbial community dynamics of brine-salted continental-type cheese in cheeses produced early and late in the production day. Differences in the microbial composition of the core and rind of the cheese were also investigated. Throughout ripening, it was apparent that cheeses produced late in the day had a more diverse microbial population than their early equivalents. Spatial variation between the cheese core and rind was also noted in that cheese rinds were initially found to have a more diverse microbial population but thereafter the opposite was the case. Interestingly, the genera Thermus, Pseudoalteromonas, and Bifidobacterium, not routinely associated with a continental-type cheese produced from pasteurized milk, were detected. The significance, if any, of the presence of these genera will require further attention. Ultimately, the use of high-throughput sequencing has facilitated a novel and detailed analysis of the temporal and spatial distribution of microbes in this complex cheese system and established that the period during a production cycle at which a cheese is manufactured can influence its microbial composition.

Construction of a dairy microbial genome catalog opens new perspectives for the metagenomic analysis of dairy fermented products

Background

Microbial communities of traditional cheeses are complex and insufficiently characterized. The origin, safety and functional role in cheese making of these microbial communities are still not well understood. Metagenomic analysis of these communities by high throughput shotgun sequencing is a promising approach to characterize their genomic and functional profiles. Such analyses, however, critically depend on the availability of appropriate reference genome databases against which the sequencing reads can be aligned.

Results

We built a reference genome catalog suitable for short read metagenomic analysis using a low-cost sequencing strategy. We selected 142 bacteria isolated from dairy products belonging to 137 different species and 67 genera, and succeeded to reconstruct the draft genome of 117 of them at a standard or high quality level, including isolates from the genera Kluyvera, Luteococcus and Marinilactibacillus, still missing from public database. To demonstrate the potential of this catalog, we analysed the microbial composition of the surface of two smear cheeses and one blue-veined cheese, and showed that a significant part of the microbiota of these traditional cheeses was composed of microorganisms newly sequenced in our study.

Conclusions

Our study provides data, which combined with publicly available genome references, represents the most expansive catalog to date of cheese-associated bacteria. Using this extended dairy catalog, we revealed the presence in traditional cheese of dominant microorganisms not deliberately inoculated, mainly Gram-negative genera such as Pseudoalteromonas haloplanktis or Psychrobacter immobilis, that may contribute to the characteristics of cheese produced through traditional methods.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1101) contains supplementary material, which is available to authorized users.

Impact of next generation sequencing techniques in food microbiology

Understanding the Maxam-Gilbert and Sanger sequencing as the first generation, in recent years there has been an explosion of newly-developed sequencing strategies, which are usually referred to as next generation sequencing (NGS) techniques. NGS techniques have high-throughputs and produce thousands or even millions of sequences at the same time. These sequences allow for the accurate identification of microbial taxa, including uncultivable organisms and those present in small numbers. In specific applications, NGS provides a complete inventory of all microbial operons and genes present or being expressed under different study conditions. NGS techniques are revolutionizing the field of microbial ecology and have recently been used to examine several food ecosystems. After a short introduction to the most common NGS systems and platforms, this review addresses how NGS techniques have been employed in the study of food microbiota and food fermentations, and discusses their limits and perspectives. The most important findings are reviewed, including those made in the study of the microbiota of milk, fermented dairy products, and plant-, meat- and fish-derived fermented foods. The knowledge that can be gained on microbial diversity, population structure and population dynamics via the use of these technologies could be vital in improving the monitoring and manipulation of foods and fermented food products. They should also improve their safety.

Microbiota characterization of a Belgian protected designation of origin cheese, Herve cheese, using metagenomic analysis

Herve cheese is a Belgian soft cheese with a washed rind, and is made from raw or pasteurized milk. The specific microbiota of this cheese has never previously been fully explored and the use of raw or pasteurized milk in addition to starters is assumed to affect the microbiota of the rind and the heart. The aim of the study was to analyze the bacterial microbiota of Herve cheese using classical microbiology and a metagenomic approach based on 16S ribosomal DNA pyrosequencing. Using classical microbiology, the total counts of bacteria were comparable for the 11 samples of tested raw and pasteurized milk cheeses, reaching almost 8 log cfu/g. Using the metagenomic approach, 207 different phylotypes were identified. The rind of both the raw and pasteurized milk cheeses was found to be highly diversified. However, 96.3 and 97.9% of the total microbiota of the raw milk and pasteurized cheese rind, respectively, were composed of species present in both types of cheese, such as Corynebacterium casei, Psychrobacter spp., Lactococcus lactis ssp. cremoris, Staphylococcus equorum, Vagococcus salmoninarum, and other species present at levels below 5%. Brevibacterium linens were present at low levels (0.5 and 1.6%, respectively) on the rind of both the raw and the pasteurized milk cheeses, even though this bacterium had been inoculated during the manufacturing process. Interestingly, Psychroflexus casei, also described as giving a red smear to Raclette-type cheese, was identified in small proportions in the composition of the rind of both the raw and pasteurized milk cheeses (0.17 and 0.5%, respectively). In the heart of the cheeses, the common species of bacteria reached more than 99%. The main species identified were Lactococcus lactis ssp. cremoris, Psychrobacter spp., and Staphylococcus equorum ssp. equorum. Interestingly, 93 phylotypes were present only in the raw milk cheeses and 29 only in the pasteurized milk cheeses, showing the high diversity of the microbiota. Corynebacterium casei and Enterococcus faecalis were more prevalent in the raw milk cheeses, whereas Psychrobacter celer was present in the pasteurized milk cheeses. However, this specific microbiota represented a low proportion of the cheese microbiota. This study demonstrated that Herve cheese microbiota is rich and that pasteurized milk cheeses are microbiologically very close to raw milk cheeses, probably due to the similar manufacturing process. The characterization of the microbiota of this particular protected designation of origin cheese was useful in enabling us to gain a better knowledge of the bacteria responsible for the character of this cheese.

Updating the Vibrio clades defined by multilocus sequence phylogeny: proposal of eight new clades, and the description of Vibrio tritonius sp. nov

To date 142 species have been described in the Vibrionaceae family of bacteria, classified into seven genera; Aliivibrio, Echinimonas, Enterovibrio, Grimontia, Photobacterium, Salinivibrio and Vibrio. As vibrios are widespread in marine environments and show versatile metabolisms and ecologies, these bacteria are recognized as one of the most diverse and important marine heterotrophic bacterial groups for elucidating the correlation between genome evolution and ecological adaptation. However, on the basis of 16S rRNA gene phylogeny, we could not find any robust monophyletic lineages in any of the known genera. We needed further attempts to reconstruct their evolutionary history based on multilocus sequence analysis (MLSA) and/or genome wide taxonomy of all the recognized species groups. In our previous report in 2007, we conducted the first broad multilocus sequence analysis (MLSA) to infer the evolutionary history of vibrios using nine housekeeping genes (the 16S rRNA gene, gapA, gyrB, ftsZ, mreB, pyrH, recA, rpoA, and topA), and we proposed 14 distinct clades in 58 species of Vibrionaceae. Due to the difficulty of designing universal primers that can amplify the genes for MLSA in every Vibrionaceae species, some clades had yet to be defined. In this study, we present a better picture of an updated molecular phylogeny for 86 described vibrio species and 10 genome sequenced Vibrionaceae strains, using 8 housekeeping gene sequences. This new study places special emphasis on (1) eight newly identified clades (Damselae, Mediterranei, Pectenicida, Phosphoreum, Profundum, Porteresiae, Rosenbergii, and Rumoiensis); (2) clades amended since the 2007 proposal with recently described new species; (3) orphan clades of genomospecies F6 and F10; (4) phylogenetic positions defined in 3 genome-sequenced strains (N418, EX25, and EJY3); and (5) description of V. tritonius sp. nov., which is a member of the “Porteresiae” clade.

Facility-specific "house" microbiome drives microbial landscapes of artisan cheesemaking plants

Cheese fermentations involve the growth of complex microbial consortia, which often originate in the processing environment and drive the development of regional product qualities. However, the microbial milieus of cheesemaking facilities are largely unexplored and the true nature of the fermentation-facility relationship remains nebulous. Thus, a high-throughput sequencing approach was employed to investigate the microbial ecosystems of two artisanal cheesemaking plants, with the goal of elucidating how the processing environment influences microbial community assemblages. Results demonstrate that fermentation-associated microbes dominated most surfaces, primarily Debaryomyces and Lactococcus, indicating that establishment of these organisms on processing surfaces may play an important role in microbial transfer, beneficially directing the course of sequential fermentations. Environmental organisms detected in processing environments dominated the surface microbiota of washed-rind cheeses maturing in both facilities, demonstrating the importance of the processing environment for populating cheese microbial communities, even in inoculated cheeses. Spatial diversification within both facilities reflects the functional adaptations of microbial communities inhabiting different surfaces and the existence of facility-specific "house" microbiota, which may play a role in shaping site-specific product characteristics.

Characterization of the bacterial diversity in Indo-West Pacific loliginid and sepiolid squid light organs

Loliginid and sepiolid squid light organs are known to host a variety of bacterial species from the family Vibrionaceae, yet little is known about the species diversity and characteristics among different host squids. Here we present a broad-ranging molecular and physiological analysis of the bacteria colonizing light organs in loliginid and sepiolid squids from various field locations of the Indo-West Pacific (Australia and Thailand). Our PCR-RFLP analysis, physiological characterization, carbon utilization profiling, and electron microscopy data indicate that loliginid squid in the Indo-West Pacific carry a consortium of bacterial species from the families Vibrionaceae and Photobacteriaceae. This research also confirms our previous report of the presence of Vibrio harveyi as a member of the bacterial population colonizing light organs in loliginid squid. pyrH sequence data were used to confirm isolate identity, and indicates that Vibrio and Photobacterium comprise most of the light organ colonizers of squids from Australia, confirming previous reports for Australian loliginid and sepiolid squids. In addition, combined phylogenetic analysis of PCR-RFLP and 16S rDNA data from Australian and Thai isolates associated both Photobacterium and Vibrio clades with both loliginid and sepiolid strains, providing support that geographical origin does not correlate with their relatedness. These results indicate that both loliginid and sepiolid squids demonstrate symbiont specificity (Vibrionaceae), but their distribution is more likely due to environmental factors that are present during the infection process. This study adds significantly to the growing evidence for complex and dynamic associations in nature and highlights the importance of exploring symbiotic relationships in which non-virulent strains of pathogenic Vibrio species could establish associations with marine invertebrates.

Reduced growth of Listeria monocytogenes in two model cheese microcosms is not associated with individual microbial strains

Two model antilisterial microbial communities consisting of two yeasts, two Gram positive and two Gram negative bacteria, and originating from Livarot cheese smear were previously designed. They were used in the present study to analyse the impact of microbial population dynamics on growth of Listeria monocytogenes in cheese microcosm. Specific culture media and PCR primers were developed for simultaneous culture-dependent and real-time PCR quantification of strains belonging to Marinomonas sp., Paenibacillus sp., Staphylococcus equorum, Arthrobacter arilaitensis, Pseudomonas putida, Serratia liquefaciens, Candida natalensis, and Geotrichum candidum, in cheese microcosms. All strains were enumerated after 3, 5, 8 and 14 days at 15 °C. They established well at high counts in all cheese microcosms. Growth dynamics for all strains in presence of L. monocytogenes WSLC 1685 were compared to those of microbial communities obtained by omitting in turn one of the six members of the initial community. The growth of the microbial strains was neither markedly disturbed by Listeria presence nor by the removal of each strain in turn. Furthermore, these communities had a significant reducing effect on growth of L. monocytogenes independently of pH, as confirmed by mathematical modelling. A barrier effect was observed, that could be explained by specific competition for nutrients.

Bacillus kochii sp. nov., isolated from foods and a pharmaceuticals manufacturing site

Three Gram-staining-positive, strictly aerobic, motile, catalase-positive, endospore-forming rods, designated WCC 4582T, WCC 4581 and WCC 4583, were isolated from two different food sources and a pharmaceuticals production site. The three isolates were highly similar in their 16S rRNA gene sequences (100 % similarity) and groEL sequences (99.2–100 % similarity), Fourier-transform infrared spectroscopic fingerprints and other features tested. The isolates were most closely related to Bacillus horneckiae ; the isolates and the type strain of B. horneckiae shared 97.6 % and 89.6 % 16S rRNA gene and groEL sequence similarities, respectively. The organisms grew optimally at 30 °C, at pH 7 and in the presence of 0.5 % (w/v) NaCl. The cell-wall peptidoglycan of WCC 4582T contained meso-diaminopimelic acid (A1γ) and the genomic DNA G+C content was 36.4 mol%. DNA–DNA relatedness between strain WCC 4582T and B. horneckiae NRRL B-59162T was 17 %. The three isolates are considered to represent a novel species of the genus Bacillus , for which the name Bacillus kochii sp. nov. is proposed. The type strain is WCC 4582T ( = DSM 23667T = CCUG 59877T = LMG 25855T).

Vibrio xiamenensis sp. nov., a cellulase-producing bacterium isolated from mangrove soil

A taxonomic study was carried out on a cellulase-producing bacterium, strain G21(T), isolated from mangrove soil in Xiamen, Fujian province, China. Cells were Gram-negative, slightly curved rods, motile with a single polar flagellum. The strain grew at 15-40 °C and in 0.5-10% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain G21(T) belonged to the genus Vibrio and formed a clade with Vibrio furnissii ATCC 350116(T) (97.4% sequence similarity), V. fluvialis LMG 7894(T) (97.1%) and V. ponticus CECT 5869(T) (96.1%). However, multilocus sequence analysis (using rpoA, recA, mreB, gapA, gyrB and pyrH sequences) and DNA-DNA hybridization experiments indicated that the strain was distinct from the closest related Vibrio species. Additionally, strain G21(T) could be differentiated from them phenotypically by the ability to grow in 10% NaCl but not on TCBS plates, its enzyme activity spectrum, citrate utilization, oxidization of various carbon sources, hydrolysis of several substrates and its cellular fatty acid profile. The G+C content of the genomic DNA was 46.0 mol%. The major cellular fatty acids were summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH), C(16:0) and C(18:1)ω7c. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol, with trace amounts of diphosphatidylglycerol. The predominant quinones were Q-8 and Q-7. Based on phylogenetic, phenotypic and chemotaxonomic characteristics and DNA-DNA hybridization analysis, it is concluded that strain G21(T) represents a novel species of the genus Vibrio, for which the name Vibrio xiamenensis sp. nov. is proposed. The type strain is G21(T) ( = DSM 22851(T)  = CGMCC 1.10228(T)).