Physiology of geosim production by Anabaena circinalis isolated from the Murrumbidgee River, Australia

Murray-Darling Freshwater Research Centre

MDFRC item.

Chemical analysis and sensory assessment of river waters from the Murrumnidgee and Murray River showed geosim 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 parralleled by similar changes in geosim/dry weight such that geosim concentrations was correlated with chlorophyll a over an extreme range of light conditions. A. circinalis was a prolific producer of geosim, but a substantial proportion of the totla geosim was often retained intra-cellularly and released on sonication or treatment with copper. Therefore water treatment processes should avoid cell lysis.