著者
Yoko Masuda Hideomi Itoh Yutaka Shiratori Kazuo Isobe Shigeto Otsuka Keishi Senoo
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME16179, (Released:2017-04-22)
被引用文献数
63

Waterlogged paddy soils possess anoxic zones in which microbes actively induce reductive nitrogen transformation (RNT). In the present study, a shotgun RNA sequencing analysis (metatranscriptomics) of paddy soil samples revealed that most RNT gene transcripts in paddy soils were derived from Deltaproteobacteria, particularly the genera Anaeromyxobacter and Geobacter. Despite the frequent detection of the rRNA of these microbes in paddy soils, their RNT-associated genes have rarely been identified in previous PCR-based studies. This metatranscriptomic analysis provides novel insights into the diversity of RNT microbes present in paddy soils and the ecological function of Deltaproteobacteria predominating in these soils.
著者
Jeonghwan Jang Naoaki Ashida Ayaaki Kai Kazuo Isobe Tomoyasu Nishizawa Shigeto Otsuka Akira Yokota Keishi Senoo Satoshi Ishii
出版者
Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME18039, (Released:2018-08-29)
被引用文献数
38

Nitrite reductase is a key enzyme for denitrification. There are two types of nitrite reductases: copper-containing NirK and cytochrome cd1-containing NirS. Most denitrifiers possess either nirK or nirS, although a few strains been reported to possess both genes. We herein report the presence of nirK and nirS in the soil-denitrifying bacterium Bradyrhizobium sp. strain TSA1T. Both nirK and nirS were identified and actively transcribed under denitrification conditions. Based on physiological, chemotaxonomic, and genomic properties, strain TSA1T (=JCM 18858T=KCTC 62391T) represents a novel species within the genus Bradyrhizobium, for which we propose the name Bradyrhizobium nitroreducens sp. nov.
著者
Kazuo Isobe Nobuhito Ohte
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.29, no.1, pp.4-16, 2014 (Released:2014-04-02)
参考文献数
143
被引用文献数
17 105

Nitrogen (N) cycles have been directly linked to the functional stability of ecosystems because N is an essential element for life. Furthermore, the supply of N to organisms regulates primary productivity in many natural ecosystems. Microbial communities have been shown to significantly contribute to N cycles because many N-cycling processes are microbially mediated. Only particular groups of microbes were implicated in N-cycling processes, such as nitrogen fixation, nitrification, and denitrification, until a few decades ago. However, recent advances in high-throughput sequencing technologies and sophisticated isolation techniques have enabled microbiologists to discover that N-cycling microbes are unexpectedly diverse in their functions and phylogenies. Therefore, elucidating the link between biogeochemical N-cycling processes and microbial community dynamics can provide a more mechanistic understanding of N cycles than the direct observation of N dynamics. In this review, we summarized recent findings that characterized the microbes governing novel N-cycling processes. We also discussed the ecological role of N-cycling microbial community dynamics, which is essential for advancing our understanding of the functional stability of ecosystems.