Research Outline

2008/8/11

Microbial energy conversion processes
Diverse microbes thrive in the environment, and we just know of less than 1% of them. Since these microbes have a variety of as-yet-unknown metabolic capacities, they are considered as attractive resources to open up new biotechnology. Researches have also been performed to utilize these microbes for the clean-up of polluted environments, waste treatments, and energy recovery from biomass. We are interested in utilizing microbes to generate electricity from sustainable resources (e.g., biomass and sun light), and have been studying their energy-conversion mechanisms. We also perform researches to develop efficient microbial fuel cells.
Molecular biology of microbial energy-conversion processes
Shewanella, an iron-reducing bacterium			Microbial fuel cell in which Shewanella generate electricity from lactate
The diversity in genetic organization of electron-transferring cytochromes
Organisms thrive on energies conserved by respiration and/or photosynthesis. Some microbes convert organics to electricity for make their livings. In order to understand their energy-conversion mechanisms, we analyze some model organisms by using molecular and genomic techniques.		Synechocystis, a phototroph	Gene-expression analyses using a microarray
Microbial solar cell containing phytotrophs
Power generation from waste biomass		Paddy-field power generation
The structure of a microbial fuel cell Microbes release electrons from organics.	Cassette-electrode microbial fuel cell
Massive amounts of waste biomass are generated as a result of human activities. We are developing microbial fuel cells (MFCs) that are applicable to generating electricity from waste biomass. We utilize complex microbial communities as anode catalysts that can stably generate electricity from biomass comprised of fluctuating and complex organics. A distinct feature of this MFC is that it enables to generate the use-friendly energy (i.e., electricity) from wastes in one step.
		In nature, there exist massive amounts of energy (e.g., organics in soil) that are difficult to be recovered by the current technology. We have constructed a system that are able to conserve energy in rice-root exudates as electricity. Rice plants produce organics by photosynthesis and exhaust some of them from roots. Soil microbes convert these organics to electricity. This is an ecological solar-cell system that can be set in a variety of environments.

By Dr. Kazuya Watanabe

Copyright (C) 2008 Kazuhito Hashimoto. All Rights Reserved.