Biodegradation of Microcystin-LR by Natural Bacterial Populations

Abstract

Microcystin-LR is a potent mammalian toxin which is known to have been responsible for the deaths of domesticated animals, and consequently there is concern as to its environmental fate. An experiment was designed to ascertain the degree of biodegradation of microcystin-LR, by enrichment of natural microbial populations from Loch Rescobie, Forfar Loch and river Carron, Scotland under aerobic conditions. It has been shown that the microcystin-LR degraded at different half-life (D1/2) in Lochs Rescobie (6.5 d), Forfar Loch (12.5 d) and river Carron (>14 d). Out of 30 bacterial isolates, 12 strains from Forfar Loch, 9 strains from Loch Rescobie, and 9 strains river Carron were isolated. Three strains from Forfar Loch, 4 strains from Loch Rescobie and 2 strains from river Carron showed strong MC-LR degradability when they were screened by Biolog MT plate using three different concentrations of MCLR (10 μgml–1, 1.0 μgml–1 and 0.1 μgml–1) as sole carbon source.