English

R R Phelan,T G Downing

doi:10.5897/ajb2007.000-2388

Abstract

Microcystin is the most common of the cyanobacterial hepatotoxins with more than 65 known variants. Increased nutrient loading of fresh and coastal water bodies has lead to an increased occurrence of cyanobacterial blooms, many of which are microcystin producing. Due to a limited commercial supply of, and difficulties in obtaining, microcystin standards, there has been an increased interest in production of purified microcystin for the use as standards in analytical laboratories. Microcystin content is however highly variable and optimised culture conditions are essential to produce viable yields of microcystin for purification. We describe the optimization of culture conditions and evaluation of various purification methods to enhance the yield of microcystin from laboratory scale culture.

Highlights

Increased eutrophication of fresh and coastal water bodies has lead to an increased occurrence of toxic cyanobacterial blooms
Single letter abbreviations are used in the naming of the toxin in order to indicate the various amino acids that are present in the toxin, i.e. MCYST-LR contains leucine (L) and arginine (R)
The optimal procedure for the production and purification of MCYST was as follows: Axenic culture was first grown in modified BG11 (7.53 mM NH4+, 25.15 mM NO3-) to an OD740nm of 1.0 at 23oC (±0.5oC) with constant illumination (11.4 mol.m-2.s-1, Triton Dayglo©) and gentle aeration (< 100 ml/min) from filtered air

Summary

Introduction

Increased eutrophication of fresh and coastal water bodies has lead to an increased occurrence of toxic cyanobacterial blooms. These blooms are unpleasant and pose a serious health threat due to the presence of toxic metabolites (Oh et al, 2000). MCYSTs form the largest group with more than 65 variants (Long et al, 2000). Single letter abbreviations are used in the naming of the toxin in order to indicate the various amino acids that are present in the toxin, i.e. MCYST-LR contains leucine (L) and arginine (R)

Methods

Results

Discussion

Conclusion