Alkalibacillus halophilus sp. nov., a new halophilic species isolated from hypersaline soil in Xin-Jiang province, China

A halophilic, Gram-positive, spore-forming motile Bacillus-like strain YIM 012(T), was isolated from one of the hypersaline soil samples collected in Xin-jiang province, China. Its optimum growth occurred at 10-20% of NaCl concentration (w/v), pH 7.0-8.0. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 012(T) is a member of the genus of Alkalibacillus, which is well supported by its chemotaxonomic and molecular characteristics. Based on its phenotypic evidence and genotypic data, Alkalibacillus halophilus sp. nov. was proposed and strain YIM 012(T) (=DSM 17369(T)=KCTC 3990(T)) was assigned as the type strain of the novel species.     

PatternLab for proteomics: a tool for differential shotgun proteomics

Background  

A goal of proteomics is to distinguish between states of a biological system by identifying protein expression differences. Liu et al. demonstrated a method to perform semi-relative protein quantitation in shotgun proteomics data by correlating the number of tandem mass spectra obtained for each protein, or "spectral count", with its abundance in a mixture; however, two issues have remained open: how to normalize spectral counting data and how to efficiently pinpoint differences between profiles. Moreover, Chen et al. recently showed how to increase the number of identified proteins in shotgun proteomics by analyzing samples with different MS-compatible detergents while performing proteolytic digestion. The latter introduced new challenges as seen from the data analysis perspective, since replicate readings are not acquired.     

<Emphasis Type="Italic">Nocardioides islandiensis</Emphasis> sp. nov., isolated from soil in Bigeum Island Korea

A novel actinobacterium designated as MSL-26^T was isolated from soil in Bigeum Island Korea. A polyphasic study was undertaken to establish the taxonomic position of isolate MSL-26^T. Strain MSL-26^T was found to have chemical and morphological characteristics similar to Nocardioides. The strain grew optimally at pH 7·5 and 28°C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MSL-26^T forms a distinct line of descent within the radiation enclosed by the genus Nocardioides. The cell wall of strain MSL-26^T contained LL-2, 6-diaminopimelic acid. The principal menaquinone was MK-8 (H₄). The phospholipids detected were diphosphatidylglycerol, phosphatidylglycerol and some unidentified lipids. C_18:1 w7c (50.38%) was the major fatty acid. The DNA G + C content of strain MSL-26^T was 71.4 mol%. The 16S rRNA gene sequence of strain MSL-26^T shares the highest sequence similarity with Nocardioides kribbensis KCTC 19038^T (95.78%) and Nocardioides aquaticus DSM 11439^T (95.52%). Based on the morphological, physiological, biochemical and chemotaxonomical data presented in this study, strain MSL-26^T should be classified as a novel species, for which the name Nocardioides islandiensis sp. nov. is proposed. The type strain is MSL-26^T (=KCTC 19275^T =DSM 19321^T)     

Agromyces indicus sp. nov., isolated from mangroves sediment in Chorao Island, Goa, India

A Gram-positive, non-motile, rod-shaped bacterium strain NIO-1018(T) isolated from a mangrove sediment sample of the Chorao Island, Goa, India, was subjected to a detailed polyphasic taxonomic study. The strain designated as NIO-1018(T) matched with most of the phenotypic and chemotaxonomic properties of the genus Agromyces and represents a novel species. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NIO-1018(T) fell within the cluster comprising species of the genus Agromyces, clustering with Agromyces soli (98.1 %), Agromyces flavus (97.9 %), Agromyces aurantiacus (97.7 %) and Agromyces ulmi (97.3 %). The predominant menaquinone was MK-12, and the major cellular fatty acids were anteiso-C(15:0), iso-C(16:0), anteiso-C(17:0) and iso-C(15:0). The polar lipids consisted of diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G+C content of strain NIO-1018(T) was 71.8 mol%. The combination of phylogenetic analysis, DNA-DNA relatedness, phenotypic characteristics and chemotaxonomic data supported the view that strain NIO-1018(T) represents a novel species of the genus Agromyces, for which the name Agromyces indicus sp. nov. is proposed. The type strain is NIO-1018 (=JCM 17573(T) = CCTCC AB2011122(T)).     

Characterization and potential evolutionary impact of transposable elements in the genome of Cochliobolus heterostrophus

Background

Cochliobolus heterostrophus is a dothideomycete that causes Southern Corn Leaf Blight disease. There are two races, race O and race T that differ by the absence (race O) and presence (race T) of ~ 1.2-Mb of DNA encoding genes responsible for the production of T-toxin, which makes race T much more virulent than race O. The presence of repetitive elements in fungal genomes is considered to be an important source of genetic variability between different species.

Results

A detailed analysis of class I and II TEs identified in the near complete genome sequence of race O was performed. In total in race O, 12 new families of transposons were identified. In silico evidence of recent activity was found for many of the transposons and analyses of expressed sequence tags (ESTs) demonstrated that these elements were actively transcribed. Various potentially active TEs were found near coding regions and may modify the expression and structure of these genes by acting as ectopic recombination sites. Transposons were found on scaffolds carrying polyketide synthase encoding genes, responsible for production of T-toxin in race T. Strong evidence of ectopic recombination was found, demonstrating that TEs can play an important role in the modulation of genome architecture of this species. The Repeat Induced Point mutation (RIP) silencing mechanism was shown to have high specificity in C. heterostrophus, acting only on transposons near coding regions.

Conclusions

New families of transposons were identified. In C. heterostrophus, the RIP silencing mechanism is efficient and selective. The co-localization of effector genes and TEs, therefore, exposes those genes to high rates of point mutations. This may accelerate the rate of evolution of these genes, providing a potential advantage for the host. Additionally, it was shown that ectopic recombination promoted by TEs appears to be the major event in the genome reorganization of this species and that a large number of elements are still potentially active. So, this study provides information about the potential impact of TEs on the evolution of C. heterostrophus.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-536) contains supplementary material, which is available to authorized users.     

Nocardioides tritolerans sp. nov., Isolated from soil in Bigeum Island, Korea

A Gram-positive strain designated as MSL-14T isolated from a soil sample collected from Bigeum Island, Korea, was subjected to polyphasic taxonomy. The isolate was strictly aerobic. Cells were short rods and motile. Optimum growth temperature and pH was 28 degrees and 7.0, respectively. It was characterized chemotaxonomically as having a cell-wall peptidoglycan type based on LL-2,6-diaminopimelic acid and MK-8(H4) as the predominant menaquinone. The major fatty acids were iso-C16:0, C17:1 omega8c, and C18:1 omega9c. The G+C content was 67.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain MSL-14T is affiliated to the genus Nocardioides and formed a distinct lineage within the genus. MSL-14T showed highest sequence similarity to Nocardioides aestuarii JCM 12125T, having a similarity of 96.5%. Based on the 16S rRNA gene sequence divergence and phenotypic characteristics, it is proposed that strain MSL-14T should be classified as representing a novel member of the genus Nocardioides, for which we propose the name Nocardioides tritolerans sp. nov. The type strain is strain MSL-14T (=KCTC 19289T= DSM 19320T).     

Isolation and Characterization of High-Strength Phenol-Degrading Novel Bacterium of the Pantoea Genus

A new indigenous soil bacterium Pantoea strain NII-153 utilizing phenol as a sole carbon source was isolated and characterized. Phylogenetic analysis suggested its classification to the Enterobacteriaceae family, with 95.0% gene sequence similarity to Pantoea ananatis ATCC 33244. Biodegradation rates of phenol by NII-153 were found to be more effective at 64 h with initial concentration of 600 mg L^{? 1} of phenol and this is the first report of such activity in Pantoea species. Strain NII-153 has showed high tolerance to phenol concentration (900 mg L^{? 1}). Therefore, strain NII-153 could be used for biotreatment of high-strength phenol-containing industrial effluents and for bioremediation of phenol-contaminated soils.     

Diversity of free-living ‘naked’ amoeboid organisms

Amoeboid organisms are phylogenetically diverse, some being more closely related to plants or metazoans than to each other. Amoeboid organisms are ecologically successful, having been isolated on all continents, including Antarctica, as well as being the main predators controlling bacterial populations in soil. The classification of these organisms has historically relied upon morphological characteristics. The application of electron microscopy, comparison of enzymic profiles after electrophoretic separation, and analysis of nucleic acid fractions have provided reliable bases for classifying amoeboid organisms. The extent of diversity of these organisms has been recognized, as methods to detect, culture, characterize and identify them has increased. It is reasonable to anticipate that the current 40 000 species of protists will increase substantially as amoeboid organisms are cultivated from poorly accessible niches and from extreme environs.