Carbon dioxide content and metabolic activity of microorganisms in some acid lakes in Japan

Abstract

The CO 2 content of the water of certain volcanic acid lakes was much higher than theoretically calculated values based on solubility in acid water. A portion of the CO 2 was derived from volcanic gas and from in situ microbial decomposition of organic matter. Considerable photosynthesis by Chlamydomonas acidophila was observed in Lake Katanuma, having a pH of 1.8 to 2.0. Growth‐pH relations of microalgae, a mold, and a yeast isolated from Lake Katanuma distinguished both extremely acid tolerant and acidophilic types.