Distinct Characteristics of Bacterial Community in the Soil of Nanshazhou Island, South China Sea.

Characterizing soil bacterial community is important to understand microbial distribution affected by environmental factors. Here, we investigated the bacterial communities distributed from different location on Nanshazhou island, South China Sea. We collected and compared soil bacterial communities from central island, intertidal island, and inshore island. Results showed no difference in the bacterial richness and diversity for the soils from the three different locations. However, weighted and unweighted UniFrac distances analysis revealed that the three soil samples were clearly separated from each other. Five bacterial phyla, including Proteobacteria, Bacteroidetes, Verrucomicrobia, Spirochaetes and Tenericutes were more abundant in the inshore island sample; while Deinococcus-Thermus was more abundant in the intertidal island sample; and the central island sample had more abundant Gemmatimonadetes and Planctomycetes. Bacterial structure showed significantly positive relationships with organic matter content, but it was significantly negatively correlated with sodium content. Furthermore, a network analysis based on Spearman correlation coefficients showed that there were similar numbers of positive and negative correlations within the bacterial community of Nanshazhou island. Our results revealed that the soil bacterial communities in the three sampling sites were easily affected by environmental fluctuations.

Bacillus vanillea sp. nov., Isolated from the Cured Vanilla Bean.

A Gram-positive bacterium, designated strain XY18(T), was isolated from a cured vanilla bean in Hainan province, China. Cells were rod-shaped, endospore producing, and peritrichous flagella. Strain XY18(T) grew at salinities of 0-8 % (w/v) NaCl (optimally 1-4 %), pH 4.0-8.0 (optimally 5.0-7.0 %) and temperature range 20-45 °C (optimally 28-35 °C). The predominant menaquinone was MK-7. The major cellular fatty acids were anteiso-C15:0, iso-C15:0, anteiso-C17:0, and iso-C17:0. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain XY18(T) was a member of the genus Bacillus, and closely related to B. amyloliquefaciens NBRC 15535(T) and B. siamensis PD-A10(T), with 99.1 and 99.2 % sequence similarity, respectively. However, the DNA-DNA hybridization value between strain XY18(T) and B. amyloliquefaciens NBRC 15535(T) was 35.7 %. The genomic DNA G+C content of strain XY18(T) was 46.4 mol%, significantly differed from B. siamensis PD-A10(T) (41.4 %), which was higher than the range of 4 % indicative of species. On the basis of polyphasic taxonomic study, including phenotypic features, chemotaxonomy, and phylogenetic analyses, strain XY18(T) represents a novel species within the genus Bacillus, for which the name Bacillus vanillea sp. nov. is proposed. The type strain is XY18(T) (=CGMCC 8629 = NCCB 100507).

[Study on the Geochemical Anomalies Identification of REE Based on HJ-1A-HSI].

The characteristic spectral bands of REE do not vary with the occurrence state, cannot be used to identify mineral species, but can prove the existence of its own. Here we report the spectrum characteristics of REE and their compounds by remote sensing wave band from visible light-near infrared, with the quantitative relationship between the contents of REE and absorption index of characteristic spectral bands. The experimental study was carried out in Bayan Obo area, Inner Mongolia. Spectrums and Nd contents of typical rock and ore samples were gathered and analyzed. There is positive correlation between the Nd content, the absorption depth and absorption index of different spectrum characteristics (correlation coefficient > 0.778). Moreover, the correlation between absorption index of 726-772 nm band and Nd content is the best, at 0. 937. As mentioned above, the quantitative model and the inversion information remote sensing geochemical anomaly of Nd were built by the band of HJ-1A-HIS hyperspectral remote sensing data. Our results consistent with 1:200,000 stream sediment geochemical anomalies of Nd. The model provides a new means for rapid extract regional geochemical anomalies of REE.

A new Neotyphodium species from Festuca parvigluma Steud. grown in China.

Neotyphodium species evolved from Epichloë species and are asexual, seedborne endophytes in many cool-season grasses. Here we propose a new species inhabiting Festuca parvigluma native to China. Morphology, host specificity and molecular phylogenetic evidence supported recognition of this new species. Sequences of beta-tubulin gene (tubB) introns and translation elongation factor 1-alpha gene (tefA) introns were present as two copies in all five isolates examined. In phylogenetic analyses copy 1 was closely related to E. yangzii in the EBY clade and copy 2 with E. typhina in the ETC clade, indicating this new species might have originated as a result of hybridization between members of these two clades. Referring to the distribution area of host plants, Neotyphodium sinofestucae is proposed for this new species.

A study of genotoxicity and oxidative stress induced by mercuric chloride in the marine polychaete Perinereis aibuhitensis.

The marine polychaete worm Perinereis aibuhitensis was used to study the genotoxic effects of mercuric chloride by means of the comet assay and micronucleus (MN) test. P. aibuhitensis was subjected in vivo to two different concentrations of mercuric chloride (0.05mgL-1 and 0.5mgL-1) for 96h. The comet assay of coelomocytes demonstrated that TailDNA% values increased with extended exposure to or increased concentrations of HgCl2 (p<0.01). The frequency of MNs was the highest in the treatment with 96h of exposure at all concentrations (p<0.01). The genotoxic effect of HgCl2 was both dose- and time-dependent in exposed P. aibuhitensis. The activities of the antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidases (GPx) were also estimated. Significant variations in antioxidant enzyme activities depended on the sampling time and the concentrations of mercuric chloride. Compared with the control, the activities of the antioxidant enzymes (SOD and GPx) were elevated at the lower concentration of mercuric chloride (0.05mg L-1) (p<0.05) for shorter exposure periods (24h and 72h). At the higher concentration of mercury (0.5mgL-1), the activities of GPx and SOD were inhibited; no variation was observed. These results proved that the use of the comet assay and MN test in coelomocytes of P. aibuhitensis is appropriate for determining the levels of DNA damage and that P. aibuhitensis is a species that is sensitive to mercury pollutants. This species may be considered a suitable candidate for monitoring marine heavy metal pollution.