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Strain AS-1 was isolated from laboratory-scale activated sludge collected in Japan. This strain not only grows on rich medium, including R2A medium, but also forms colonies on medium lacking organic matter other than agar (water agar), indicating it could be used as a eurytrophic recombinant host in material production processes. Here, we present a draft genome sequence of Enterobacter sp. AS-1, which consists of a total of 24 contigs containing 5,207,146 bp, with a GC content of 55.64%, and comprising 4,921 predicted coding sequences. Based on 16S rRNA gene sequence analysis, strain AS-1 was designated as Enterobacter sp. AS-1.

An aerobic, oligotrophic, Gram-positive, non-sporulating, motile, rod-shaped, palladium-leaching bacterial strain, Deinococcus sp. KR-1, was previously isolated from pond water collected in Japan. This strain grew at 10 °C to 40 °C (optimum 30 °C), at pH 4.5 to 11.5 (optimum pH 8.0), and in the presence of 2.0% NaCl. Its major cellular fatty acids were C15: 1ω6 and C16 : 1ω7c. The quinone system was menaquinone 8. Multilocus sequence analysis based on partial sequences of four housekeeping genes (atpD, dnaA, gyrB and rpoB) showed that branching of Deinococcus sp. KR-1 was distant to those of Deinococcus type strains. The genome average nucleotide identity value between strain KR-1 and its closest related Deinococcus type strain was less than 95.69%. Based on its phenotypic, chemotaxonomic and phylogenetic data, strain KR-1 (= HUT-8138T = KCTC 33977T) can be considered a novel species within the genus Deinococcus with the proposed name Deinococcus kurensis sp. nov.

Methanogens capable of accepting electrons from Fe

In this study, the microbial community for denitrification in the down-flow hanging sponge (DHS) reactor was estimated by batch experiment and microbial community analysis. Sludge retained from the DHS reactor, which conducts single-stage nitrification-denitrification, was collected into a series of vials as seed sludge for the batch experiment. Nitrate, nitrite, and nitrous oxide were added as nitrogen sources for each vial series. Sodium acetate solution was added to each vial series as a carbon source. At the beginning of the batch experiment, nitrous oxide was accumulated from only the nitrite-fed series (NO2 series). Approximately 50% of reduced nitrate was accumulated as nitrite in the nitrate-fed series (NO3 series). After two weeks of cultivation, nitrous oxide began to accumulate in the NO3 series without nitrite accumulation. Nitrous oxide accumulation was not confirmed in the NO3 series after 15 days of cultivation. During the batch experiment, the predominant denitrifying bacteria changed from Alicycliphilus to Thauera in the NO3 series. By contrast, the nitrous oxide producer Propionibacterium and the nitrous oxide reducer Staphylococcus increased in the NO2 series only. Thus, nitrite accumulation was considered to be a key factor for nitrous oxide emission in the DHS reactor. In addition, it was suggested that both nitrifying and denitrifying bacteria contributed to prevention of nitrite accumulation in the DHS reactor.