GO TOP

Field

Ecological Developmental Adaptability Life Sciences :
Specially-appointed Professor

Research

Specially-appointed Professor MINAMISAWA Kiwamu
Campus Katahira campus
Laboratory Soil Microbiology
Tel +81-22-217-5684
E-mail kiwamu@ige.tohoku.ac.jp
Website http://www.ige.tohoku.ac.jp/chiken/index.html
Google scholar

https://scholar.google.com/citations?user=gBIKdJ0AAAAJ&hl=en

From recent research, we know that plants respond to environmental changes such as low nitrogen, and select symbiotic microorganisms. When microorganisms acquire symbiotic associations with plants, they acquire an enhanced risk of genome instability. Even more interestingly, plant root-associated microbes are deeply connected to N and C transformation in the rhizosphere, wherein greenhouse gases (N2O and CH4) are produced and extinguished. My aim is to discover diversity and functions of dynamic plant-associated microorganisms, and to develop multidisciplinary sciences for application to environmental microbiology for the purposes of sustainable agriculture and environmental conservation.

Career

1983 Assistant Professor, Faculty of Agriculture, Ibaraki University
1990 Associate Professor, Faculty of Agriculture, Ibaraki University
1996 Professor, Institute of Genetic Ecology, Tohoku University
2001 Professor, Graduate School of Life Science, Tohoku University

Selected Publications
  1. Minamisawa et al. 2016. Are symbiotic methanotrophs key microbes for N acquisition in paddy rice root? Microbes Environ. 31: 4-10.
  2. Akiyama et al. 2016. Mitigation of soil N2O emission by inoculation with a mixed culture of indigenous Bradyrhizobium diazoefficiens. Scientific Reports 6: 32869.
  3. Igai et al. 2016. Nitrogen fixation and nifH diversity in human gut microbiota. Scientific Reports 6: 31942.
  4. Hidaka et al. 2015. Visualization of NO3-/NO2- dynamics in living cells by fluorescence resonance energy transfer (FRET) imaging employing a rhizobial two-component regulatory system. J. Biol. Chem. 291: 2260-2269.
  5. Anda et al. 2015. Bacterial clade with the ribosomal RNA operon on a small plasmid rather than the chromosome. Proceedings of the National Academy of Sciences, 112: 14343-14347.
  6. Iida et al. 2015. Symbiosis island shuffling with abundant insertion sequences in the genomes of extra-slow-growing strains of soybean bradyrhizobia. Appl. Environ. Microbiol. 81:4143-4154.
  7. Okubo et al. 2015. Elevated atmospheric CO2 levels affect community structure of rice root-associated bacteria. Front. Microbiol. 6: 136.
  8. Shiina et al. 2014. Correlation between soil type and N2O reductase genotype (nosZ) of indigenous soybean bradyrhizobia: nosZ-minus populations are dominant in Andosols. Microbes Environ. 29: 420-426.
  9. Sanchez et al. 2014. The nitrate-sensing NasST system regulates nitrous oxide reductase and periplasmic nitrate reductase in Bradyrhizobium japonicum. Environ. Microbiol. 16: 3263-3274
  10. Bao et al. 2014. Metaproteomic identification of diazotrophic methanotrophs and their localization in root tissues of field-grown rice plants. Appl. Environ. Microbiol. 80: 5043-5052. (Research Highlight selected)
  11. Bao et al. 2014. A rice gene for microbial symbiosis, Oryza sativa CCaMK, reduces CH4 flux in a paddy field with low nitrogen input. Appl. Environ. Microbiol. 80: 1995-2003. (Research Highlight selected)
  12. Ikeda et al. 2014. Low nitrogen fertilization adapts rice root microbiome to low nutrient environment by changing biogeochemical functions. Microbes Environ. 29: 50-59.
  13. Itakura et al. 2013. Mitigation of nitrous oxide emissions from soils by Bradyrhizobium japonicum inoculation. Nature Climate Change 3: 208-212.
  14. Okubo et al. 2013. Genome anlaysis suggests that the soil oligotrophic bacterium Agromonas oligotrophica (Bradyrhizobium oligotrophicum) is a nitrogen-fixing symbiont of Aeschynomene indica. Appl. Environ. Microbiol. 79: 2542-2551.
  15. Ikeda, S., T. Ohkubo, T. Kaneko, S. Inaba, T. Maekawa, S. Eda, S. Sato, S. Tabata, H. Mitsui, and K. Minamisawa. 2010. Community shifts of soybean stem-associated bacteria responding to different nodulation phenotypes and N levels. ISME Journal 4: 315-26.
  16. Itakura et al. 2009. Genomic comparison of Bradyrhizobium japonicum strains with different symbiotic nitrogen-fixing capabilities and other Bradyrhizobiaceae members. ISME J. 3: 326-339.
Activities in Academic Societies

Japanese Society of Microbial Ecology, Japan Society of Plant Microbe Interactions, Japan Society of Soil Science and Plant Nutrition, Japanese Society of Soil Microbiology, Japan Society for Bioscience, Biotechnology and Agrochemistry, International Society of Microbial Ecology (ISME)

Recent Activities

Focusing on bacterial genomics, I am studying 1) symbiotic mechanisms between legume plants and their microsymbionts, rhizobial (root nodule) bacteria; 2) soil microbe-mediated biogeochemical functions relevant to N and C transformation in plant rhizospheres; and 3) co-evolution of rhizobia and leguminous plants. Recently, I have enthusiastically been conducting research to find out why soybean disease resistant genes are involved in the incompatibility between soybean plants and specific strains of the endosymbiont, Bradyrhizobium japonicum. I am also conducting global environmental research on the close relationship between rhizobial denitrification potential and the generation of the global warming gas N2O emitted from legume roots. In addition, our group found a new regulatory system for the nosZ gene encoding N2O reductase, and proposed a strategy to reduce soil N2O emission by enhancing nosZ expression. In the natural world, many microorganisms function through their interactions as communities, and I have discovered the general rules thereof using root nodule bacteria and endophytes.

Message to Students

Academia in the future will not just be meticulous analysis and investigation of a single phenomenon. It will become more and more important to integrate and open new multidisciplinary fields. For this reason, it is essential to ambitiously learn not only the basics but related fields as well. If you’re interested in symbiosis and soil microorganisms, I implore you to come visit our laboratory.