Bacillus beringensis sp. nov., a psychrotolerant bacterium isolated from the Bering Sea

Robust demarcation of 17 distinct Bacillus species clades, proposed as novel Bacillaceae genera, by phylogenomics and comparative genomic analyses: description of Robertmurraya kyonggiensis sp. nov. and proposal for an emended genus Bacillus limiting it only to the members of the Subtilis and Cereus clades of species

To clarify the evolutionary relationships and classification of Bacillus species, comprehensive phylogenomic and comparative analyses were performed on >300 Bacillus/Bacillaceae genomes. Multiple genomic-scale phylogenetic trees were initially reconstructed to identify different monophyletic clades of Bacillus species. In parallel, detailed analyses were performed on protein sequences of genomes to identify conserved signature indels (CSIs) that are specific for each of the identified clades. We show that in different reconstructed trees, most of the Bacillus species, in addition to the Subtilis and Cereus clades, consistently formed 17 novel distinct clades. Additionally, some Bacillus species reliably grouped with the genera Alkalicoccus, Caldalkalibacillus, Caldibacillus, Salibacterium and Salisediminibacterium. The distinctness of identified Bacillus species clades is independently strongly supported by 128 identified CSIs which are unique characteristics of these clades, providing reliable means for their demarcation. Based on the strong phylogenetic and molecular evidence, we are proposing that these 17 Bacillus species clades should be recognized as novel genera, with the names Alteribacter gen. nov., Ectobacillus gen. nov., Evansella gen. nov., Ferdinandcohnia gen. nov., Gottfriedia gen. nov., Heyndrickxia gen. nov., Lederbergia gen. nov., Litchfieldia gen. nov., Margalitia gen. nov., Niallia gen. nov., Priestia gen. nov., Robertmurraya gen. nov., Rossellomorea gen. nov., Schinkia gen. nov., Siminovitchia gen. nov., Sutcliffiella gen. nov. and Weizmannia gen. nov. We also propose to transfer 'Bacillus kyonggiensis' to Robertmurraya kyonggiensis sp. nov. (type strain: NB22=JCM 17569^T=DSM 26768). Additionally, we report 31 CSIs that are unique characteristics of either the members of the Subtilis clade (containing the type species B. subtilis) or the Cereus clade (containing B. anthracis and B. cereus). As most Bacillus species which are not part of these two clades can now be assigned to other genera, we are proposing an emended description of the genus Bacillus to restrict it to only the members of the Subtilis and Cereus clades.

Large Blooms of Bacillales (Firmicutes) Underlie the Response to Wetting of Cyanobacterial Biocrusts at Various Stages of Maturity

Biological soil crusts (biocrusts) account for a substantial portion of primary production in dryland ecosystems. They successionally mature to deliver a suite of ecosystem services, such as carbon sequestration, water retention and nutrient cycling, and climate regulation. Biocrust assemblages are extremely well adapted to survive desiccation and to rapidly take advantage of the periodic precipitation events typical of arid ecosystems. Here we focus on the wetting response of incipient cyanobacterial crusts as they mature from "light" to "dark." We sampled a cyanobacterial biocrust chronosequence before (dry) and temporally following a controlled wetting event and used high-throughput 16S rRNA and rRNA gene sequencing to monitor the dynamics of microbial response. Overall, shorter-term changes in phylogenetic beta diversity attributable to periodic wetting were as large as those attributable to biocrust successional stage. Notably, more mature crusts showed significantly higher resistance to precipitation disturbance. A large bloom of a few taxa within the Firmicutes, primarily in the order Bacillales, emerged 18 h after wetting, while filamentous crust-forming cyanobacteria showed variable responses to wet-up across the successional gradient, with populations collapsing in less-developed light crusts but increasing in later-successional-stage dark crusts. Overall, the consistent Bacillales bloom accompanied by the variable collapse of pioneer cyanobacteria of the Oscillatoriales order across the successional gradient suggests that the strong response of few organisms to a hydration pulse with the mortality of the autotroph might have important implications for carbon (C) balance in semiarid ecosystems.IMPORTANCE Desert biological soil crusts are terrestrial topsoil microbial communities common to arid regions that comprise 40% of Earth's terrestrial surface. They successionally develop over years to decades to deliver a suite of ecosystem services of local and global significance. Ecosystem succession toward maturity has been associated with both resistance and resilience to disturbance. Recent work has shown that the impacts of both climate change and physical disturbance on biocrusts increase the potential for successional resetting. A larger proportion of biocrusts are expected to be at an early developmental stage, hence increasing susceptibility to changes in precipitation frequencies. Therefore, it is essential to characterize how biocrusts respond to wetting across early developmental stages. In this study, we document the wetting response of microbial communities from a biocrust chronosequence. Overall, our results suggest that the cumulative effects of altered precipitation frequencies on the stability of biocrusts will depend on biocrust maturity.

Role of fatty acids in Bacillus environmental adaptation

The large bacterial genus Bacillus is widely distributed in the environment and is able to colonize highly diverse niches. Some Bacillus species harbor pathogenic characteristics. The fatty acid (FA) composition is among the essential criteria used to define Bacillus species. Some elements of the FA pattern composition are common to Bacillus species, whereas others are specific and can be categorized in relation to the ecological niches of the species. Bacillus species are able to modify their FA patterns to adapt to a wide range of environmental changes, including changes in the growth medium, temperature, food processing conditions, and pH. Like many other Gram-positive bacteria, Bacillus strains display a well-defined FA synthesis II system that is equilibrated with a FA degradation pathway and regulated to efficiently respond to the needs of the cell. Like endogenous FAs, exogenous FAs may positively or negatively affect the survival of Bacillus vegetative cells and the spore germination ability in a given environment. Some of these exogenous FAs may provide a powerful strategy for preserving food against contamination by the Bacillus pathogenic strains responsible for foodborne illness.

Diversity and morphological structure of bacterial communities inhabiting the Diana-Hygieia Thermal Spring (Budapest, Hungary)

The Buda Thermal Karst System is an active hypogenic karst area that offers possibility for the analysis of biogenic cave formation. The aim of the present study was to gain information about morphological structure and genetic diversity of bacterial communities inhabiting the Diana-Hygieia Thermal Spring (DHTS). Using scanning electron microscopy, metal accumulating and unusual reticulated filaments were detected in large numbers in the DHTS biofilm samples. The phyla Actinobacteria, Firmicutes and Proteobacteria were represented by both bacterial strains and molecular clones but phyla Acidobacteria, Chlorobi, Chlorofexi, Gemmatimonadetes, Nitrospirae and Thermotogae only by molecular clones which showed the highest similarity to uncultured clone sequences originating from different environmental sources. The biofilm bacterial community proved to be somewhat more diverse than that of the water sample and the distribution of the dominant bacterial clones was different between biofilm and water samples. The majority of biofilm clones was affiliated with Deltaproteobacteria and Nitrospirae while the largest group of water clones was related to Betaproteobacteria. Considering the metabolic properties of known species related to the strains and molecular clones from DHTS, it can be assumed that these bacterial communities may participate in the local sulphur and iron cycles, and contribute to biogenic cave formation.

Phylogenetic diversity of bacterial communities inhabiting the sediment of Lake Hévíz - a comparison of cultivation and cloning

Lake Hévíz is the largest natural warm water lake of Europe. The curative mud of the lake comprises volcanic and marsh components although their species composition is hardly known yet. The aim of the present study was to gain information about the distribution and species diversity of bacterial communities inhabiting the sediment of Lake Hévíz using cultivation-based and molecular cloning methods. Samples from two depths and locations were taken in 2004 and 2007. Representatives of the altogether 255 bacterial isolates were affiliated with the phyla Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes. The most abundant groups belonged to the genus Bacillus (Firmicutes). Many of Lake Hévíz isolates showed the highest sequence similarity to bacteria known to be plant associated or members of normal human microbiota as well as participating in decomposition of highly resistant organic materials. In the three clone libraries, phylotypes belonging to altogether different phyla (Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Cyanobacteria, Chlorobi, Chloroflexi, Deferribacteres, Nitrospirae, Spirochaetes and Verrucomicrobia) were revealed from which members of Gammaproteobacteria and Cyanobacteria proved to be the most abundant. Regardless of the sampling times and methodology used, high spatial heterogeneities of bacterial community structures were characteristic of the sediment of Lake Hévíz.

List of new names and new combinations previously effectively, but not validly, published

The purpose of this announcement is to effect the valid publication of the following effectively published new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper, to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries. It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below, and these authors’ names will be included in the author index of the present issue. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in bacteriological nomenclature. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.