PRODUCTION OF EXOMETABOLITES IN THE MICROBIAL OXIDATION OF METHANE INMARINE ECOSYSTEMS

The fraction of methane carbon incorporated into organic exometabolite s (OE) during aerobic and anaerobic microbial oxidation of methane in marine waters and sediments in different climatic zones was determined . The major part of methane in bottom sediments was found to be oxidiz ed to carbon dioxide. In methane oxidation proceeding in seawater, the fraction of methane carbon revealed in OE was 35-85% on average. Typi cally, an increase in the total rate of methane oxidation occurred con currently with a fall in the production of OE. It is shown that the ca lculations of microbial oxidation of methane in marine ecosystems base d solely on the amount of carbon dioxide produced may well underestima te (by a factor of 1.5-2) the actual scale of biological oxidation of this gas.