PHYSIOLOGY OF GEOSMIN PRODUCTION BY ANABAENA-CIRCINALIS ISOLATED FROM THE MURRUMBIDGEE RIVER, AUSTRALIA

Chemical analysis and sensory assessment of river waters from the Murrumbidgee and Murray Rivers showed geosmin is an important odor compound. Experiments in culture using Anabaena circinalis isolated from the Murrumbidgee River, New South Wales, Australia showed that changes in chlorophyll per unit dry weight resulting from alterations in light intensity were paralleled by similar changes in geosmin/dry weight such that geosmin concentration was correlated with chlorophyll a over an extreme range of light conditions. A. circinalis was a prolific producer of geosmin, but a substantial proportion of the total geosmin was often retained intra-cellularly and released on sonication or treatment with copper. Therefore water treatment processes should avoid cell lysis.