Abstract
One of the gases which scientists have so much concern related to global warming is methane. Although amounts of methane release to atmosphere from ocean and coastal areas are not so enormous compared with wetlands and rice paddies, methane stock in the sediments is considered to be big amount. It means probably that methane produced by microbial activity is oxidized and recycled also by the aerobic and anaerobic microbial activity in the sediments and waters. Unfortunately, however, quite few information is now available on the methanogenic activity related to population of methanogenic bacteria and other groups of microorganisms. In this paper, we mentioned about our study on methanogenic bacteria conducted in the Japanese coastal waters and also reviewed the studies of them which have been done in various regions.
