Draft genome sequence of Bacteroides faecis MAJ27T, a strain isolated from human feces

Despite the ecological importance of the dominant gut bacteria Bacteroides, few genomes have been defined. The Gram-negative, strictly anaerobic intestinal bacterium Bacteroides faecis MAJ27(T) was isolated from the feces of a healthy adult. Here, the draft genome sequence of the type strain B. faecis MAJ27 (6.11 Mbp) is reported.     

Effects of blood flow to the prefrontal cortex on high-intensity exercise combined with high-decibel music

We studied the effects of high-intensity exercise (70-75% of VO₂ max) combined with high-decibel music (100 dB) on cognitive function (measured by the Stroop test) and related blood flow changes to the prefrontal cortex (measured by Oxy-hemoglobin (Hb), Deoxy-Hb, tissue oxygen index (TOI), and normalized tissue hemoglobin index (nTHI)). The subjects of the study were 28 healthy female university students in their early 20s. Subjects were categorized into control group (CG), music group (MG), exercise group (Ex), and music and exercise group (MnEx). A crossover design was implemented so that all subjects participated in all test groups. We found no significant difference in reaction time between CG and MG for the neutral and incongruent tasks of Stroop test. However, there were significant improvements in the neutral and incongruent tasks for both the Ex (p < 0.01) and MnEx (p < 0.01) groups. Oxy-Hb measurements in the prefrontal cortex of the brain supported the Stroop test data. We found no difference between Ex and MnEx in the TOI; however, there was a significant decrease (p < 0.05) in MnEx compared to Ex. In addition, Ex resulted in a significant increase (p < 0.05) in nTHI as compared to CG. These results indicate that high decibel music could negatively affect prefrontal cortex activation of the brain during exercise.     

Genome sequence of strain TW15, a novel member of the genus Ruegeria, belonging to the marine Roseobacter clade

Ruegeria sp. TW15, which belongs to the family Rhodobacteraceae, was isolated from an ark clam in the South Sea of Korea. Here is presented the draft genome sequence of Ruegeria sp. TW15 (4,490,771 bp with a G+C content of 55.7%), a member of the marine Roseobacter clade, which comprises up to 20% of the bacterioplankton in the coastal and oceanic mixed layer.     

Insect Gut Bacterial Diversity Determined by Environmental Habitat,Diet, Developmental Stage,and Phylogeny of Host

Insects are the most abundant animals on Earth, and the microbiota within their guts play important roles by engaging in beneficial and pathological interactions with these hosts. In this study, we comprehensively characterized insect-associated gut bacteria of 305 individuals belonging to 218 species in 21 taxonomic orders, using 454 pyrosequencing of 16S rRNA genes. In total, 174,374 sequence reads were obtained, identifying 9,301 bacterial operational taxonomic units (OTUs) at the 3% distance level from all samples, with an average of 84.3 (±97.7) OTUs per sample. The insect gut microbiota were dominated by Proteobacteria (62.1% of the total reads, including 14.1% Wolbachia sequences) and Firmicutes (20.7%). Significant differences were found in the relative abundances of anaerobes in insects and were classified according to the criteria of host environmental habitat, diet, developmental stage, and phylogeny. Gut bacterial diversity was significantly higher in omnivorous insects than in stenophagous (carnivorous and herbivorous) insects. This insect-order-spanning investigation of the gut microbiota provides insights into the relationships between insects and their gut bacterial communities.     

Development of enrichment semi-nested PCR for Clostridium botulinum types A, B, E, and F and its application to Korean environmental samples

An enrichment semi-nested PCR procedure was developed for detection of Clostridium botulinum types A, B, E, and F. It was applied to sediment samples to examine the prevalence of C. botulinum in the Korean environment. The first pair of primers for the semi-nested PCR was designed using a region shared by the types A, B, E, and F neurotoxin gene sequences, and the second round employed four nested primers complementary to the BoNT/A, /B, /E, and /F encoding genes for simultaneous detection of the four serotypes. Positive results were obtained from the PCR analysis of five of 44 sediments (11%) collected from Yeong-am Lake in Korea; all were identified as deriving from type B neurotoxin (bontb) genes. Two of the C. botulinum type B organisms were isolated, and their bontb genes sequenced. The deduced amino acid sequences of BoNT/B showed 99.5 and 99.8% identity with the amino acid sequence of accession no. AB084152. Our data suggest that semi-nested PCR is a useful tool for detecting C. botulinum in sediments, and renders it practicable to conduct environmental surveys.     

Nitric oxide synthesis contributes to inhibition of graft-versus-tumor-effects against intraperitoneal Meth A tumor

The role of nitric oxide (NO) in graft-versus-tumor-effect (GVT) was evaluated in the present study. GVT was induced by intravenous injection of C57BL/6J (H-2b) mouse splenocytes to {C57BL/6J (H-2b) x BALB/c (H-2d)} F1 mice bearing Meth A (H-2d) ascites tumors. Induction of GVT increased nitrite production and expression of inducible NO synthase by ascites cells. The increased nitrite production was inhibited by NG-monomethyl-L-arginine (MLA). Experiments employing immunomagnetic depletion of Mac-1+ cells from ascites indicated that macrophages were a major cellular source of the nitrite production. Interferon-gamma levels were increased in both serum and ascites fluid during GVT. Induction of GVT prolonged survival of ascites-bearing mice, and increased urinary nitrate excretion. MLA administration inhibited GVT-induced increase in urinary nitrate excretion, and further prolonged GVT-induced increase in survival. These results indicate that NO synthesis is induced in tumors during GVT, and the NO acts as an inhibitor of GVT.