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Changes in the intestinal microbiota are known to occur in constipated patients. Dietary fiber restriction presents obstacles to appropriate defecation and affects fecal properties, but the relationship between fecal microbiota and fecal morphological properties remains obscure. Therefore, we examined the influence of fiber diets on the fecal microbiome and properties in rats, and the effectiveness of the Japanese traditional medicine Junchoto (JCT) in rats with fiber deficit-induced constipation. Rats were fed three different fiber diets with varying cellulose contents (0 %, FFD; 5 %, ND; 15 %, HFD), respectively, as follows: study 1: 21 days of feeding; study 2: 14 days of feeding followed by 7 days of ND (fiber normalization in all groups); study 3: FFD for 21 days, followed by JCT administration from 14 days. Fecal properties and 16S rRNA amplicon sequencing results were examined. We observed that the fecal frequency, dry weight, and length were increased, and water ratio were decreased in a cellulose dose-dependent manner. The difference in several kinds of fecal microbiota, but not the α-diversity Chao1 index and the Firmicutes/Bacteroidetes ratio (F/B ratio), between groups were observed. The change in fecal property in both the HFD and FFD groups was ameliorated with fiber normalization, accompanied by alteration of the Chao1 index and/or F/B ratio. JCT administration reversed the fecal morphological changes in FFD group, accompanied by F/B ratio increasing. In conclusion, short-term dietary changes modulated microbial homeostasis, which is linked to fecal property. JCT may alter the F/B ratio and improve fecal properties to facilitate easier excretion., (Copyright © 2022. Published by Elsevier Masson SAS.)

A novel facultatively anaerobic, nitrate-reducing bacterium, designated MeG22 T , was isolated from a freshwater lake in Japan. Cells of the strain were straight rods (0.8×2.5-10 µm), motile, and Gram-stain-negative. For growth, the optimum NaCl concentration was 0 % and the optimum temperature was 30 °C. Under anoxic conditions, strain MeG22 T reduced nitrate to nitrite. Major cellular fatty acids were C 15 : 1  ω6 c (13.6 %), C 17 : 0 (11.9 %), anteiso-C 15 : 0 (10.6 %) and iso-C 15 : 0 (10.6 %). The major respiratory quinone was menaquinone-7. The genome sequence of strain MeG22 T consists of 5 712 279 bp with a G+C content of 40.3 mol%. Phylogenetic analysis based on the 16S rRNA gene revealed that the novel strain belonged to the family Prolixibacteraceae within the phylum Bacteroidetes . The closest relative of strain MeG22 T was Sunxiuqinia faeciviva strain JAM-BA0302 T with a 16S rRNA gene sequence similarity of 90.9 %. On the basis of phylogenetic and phenotypic characterization, Aquipluma nitroreducens , gen. nov., sp. nov., belonging to the family Prolixibacteraceae is proposed with the type strain MeG22 T (=NBRC 112896 T =DSM 106262 T ).

Ambient particle (PM 2.5 ) samples were collected in three East Asian cities (Beijing, China; Seoul, South Korea; Nagasaki, Japan) from December 2014 to November 2015 to quantitatively investigate airborne bacteria at the phylum level. Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Cyanobacteria represented the top five airborne bacterial phyla in all three cities. The most dominant airborne phylum, Proteobacteria, was more prevalent during the winter (at rates of 67.2%, 79.9%, and 87.0% for Beijing, Seoul, and Nagasaki, respectively). Correlations among airborne bacteria and environmental factors including PM 2.5 , its major chemical constituents, and meteorological factors were calculated. Temperature correlated negatively with Proteobacteria but positively with Firmicutes and Bacteroidetes. The abundance of Cyanobacteria correlated positively with particulate NO 3 - and SO 4 2- levels in Beijing (R = 0.46 and R = 0.35 for NO 3 - and SO 4 2- , respectively) but negatively in Seoul (R = -0.14 and R = -0.19 for NO 3 - and SO 4 2- , respectively) and Nagasaki (R = -0.05 and R = -0.03 for NO 3 - and SO 4 2- , respectively). Backward trajectory analysis was applied for 72 h and three clusters were classified in each city. Five dominant bacteria and other bacterial groups showed significant differences (p < 0.05) in local clustering, as compared to the long-range transport clusters from Beijing. The proportions of the five bacterial phyla in Seoul were significantly different in each cluster. A local cluster in Nagasaki had higher ratios of all major airborne bacterial phyla, except Proteobacteria., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A wide range of invertebrates harbor intracellular endosymbiotic bacteria. Within these endosymbionts, Wolbachia and Cardinium, have been attracting particular attention because these bacteria frequently affect the genetic structure and genetic diversity of their hosts. They cause various reproductive alterations such as cytoplasmic incompatibility, parthenogenesis induction, male-killing, and feminization. Through these alterations, they also affect the maternally inherited organelles of their hosts. Mitochondrial DNA (mtDNA) can be used for molecular phylogenetic analysis of invertebrates. However, in Wolbachia- or Cardinium-infected invertebrates, phylogenetic trees based on mtDNA are often inconsistent with those based on nuclear DNA. In the present study, we determined the Wolbachia/Cardinium infection status of 45 populations of the mite, Oligonychus castaneae Ehara & Gotoh (Acari: Tetranychidae), collected throughout Japan. Then, we compared phylogenetic trees of O. castaneae based on both the cytochrome c oxidase subunit I (COI) gene of mtDNA and the 28S rRNA gene of nuclear DNA to clarify the effects of Wolbachia and/or Cardinium infection. We found 106 Wolbachia-infected individuals and 250 Cardinium-infected individuals in a total of 450 individuals, indicating an infection rate of 79%. No double-infected individuals were observed. In the 28S tree, almost all populations formed a single group. In the COI tree, O. castaneae formed four separate groups that more closely followed Wolbachia/Cardinium infection than geographic distribution. These results strongly suggest that the endosymbionts affected mitochondrial variation of O. castaneae., (© The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Benzo[a]pyrene (BaP) is one of the polycyclic aromatic hydrocarbons, and has serious detrimental effects on human health and aquatic environments. In this study, we isolated nine bacterial strains capable of degrading BaP from the Tokyo Bay area and Tama River in Japan. The isolated bacteria belonged to the phyla Actinobacteria, Firmicutes, Proteobacteria and Bacteroidetes, indicating that the BaP-degrading bacteria were widely present in the hydrosphere. ITB11, which shared 100% 16S rRNA identity with Mesoflavibacter zeaxanthinifaciens in the phylum Bacteroidetes, showed the highest degradation of BaP (approximately 86%) among the nine isolated strains after 42 days. Moreover, it was found that three of the nine isolated strains collectively removed 50-55% of BaP during the first 7 days. Growth measurement of M. zeaxanthinifaciens revealed that the strain utilized BaP as a sole carbon and energy source and salicylate acted only as an inducer of BaP degradation., (© FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)