TY  - JOUR
A1  - Meissner, Sven
A1  - Fastner, Jutta
A1  - Dittmann-Thünemann, Elke
T1  - Microcystin production revisited conjugate formation makes a major contribution
JF  - Environmental microbiology
N2  - The impact of environmental stimuli on the production of the widespread cyanobacterial hepatotoxin microcystin (MC) is under debate. Whereas transcriptional studies of the biosynthetic genes suggest a clear influence of light conditions on toxin production the data for the metabolite itself are inconsistent and highly strain-specific. Here, we have reassessed the MC content by using two immunological detection techniques that allow a parallel quantification of MC in the methanolic extracts and the residual pellet fraction that contains high molecular weight proteins. Our results show a significant proportion of MC in the protein bound fraction in strains of Microcystis and Planktothrix and of the related toxin nodularin (NOD) in Nodularia. Moreover, we could show a very strong increase of MC after high light illumination in the protein fraction contributing to a significant overall increase in MC production under these conditions that is not seen in extracts analysed by LC-MS and ELISA. The fact that a considerable portion of MC is neglected with current analysis techniques was also confirmed for selected field samples. Immunofluorescence studies suggest strain-specific differences in the amount of MC conjugate formation.
Y1  - 2013
U6  - https://doi.org/10.1111/1462-2920.12072
SN  - 1462-2912
VL  - 15
IS  - 6
SP  - 1810
EP  - 1820
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -