Predicting blooms of toxic cyanobacteria in eutrophic lakes with diverse cyanobacterial communities

Abstract

We investigated possibility of predicting whether blooms, if they occur, would be formed of microcystin-producing cyanobacteria. DGGE analysis of 16S-ITS and mcyA genes revealed that only Planktothrix and Microcystis possessed mcy-genes and Planktothrix was the main microcystin producer. qPCR analysis revealed that the proportion of cells with mcy-genes in Planktothrix populations was almost 100%. Microcystin concentration correlated with the number of potentially toxic and total Planktothrix cells and the proportion of Planktothrix within all cyanobacteria, but not with the proportion of cells with mcy-genes in total Planktothrix. The share of Microcystis cells with mcy-genes was low and variable in time. Neither the number of mcy-possessing cells, nor the proportion of these cells in total Microcystis, correlated with the concentration of microcystins. This suggests that it is possible to predict whether the bloom in the Masurian Lakes will be toxic based on Planktothrix occurrence. Two species of toxin producing Planktothrix, P. agardhii and P. rubescens, were identified by phylogenetic analysis of 16S-ITS. Based on morphological and ecological features, the toxic Planktothrix was identified as P. agardhii. However, the very high proportion of cells with mcy-genes suggests P. rubescens. Our study reveals the need of universal primers for mcyA genes from environment.

Limited Microcystin, Anatoxin and Cylindrospermopsin Production by Cyanobacteria from Microbial Mats in Cold Deserts

“…The HEP primers [40] only ideally fit mcyE sequences from Microcystis, while mcyE primers [41] additionally ideally fit the Fischerella sequences. The uncertainty about primers' universality to detect toxin-encoding genes in planktonic taxa is discussed in Bukowska et al [24].…”

TRI Genotyping and Chemotyping: A Balance of Power

“…As such, on the basis of the proportion of potentially 'toxic' genotypes, it should be possible to predict whether there is a risk of toxin production and subsequent exposure [40]. A number of studies have utilized genotyping as a proxy to determining chemotype [41][42][43][44][45][46][47][48][49]. Table 3 outlines the various research efforts in applying TRI genotyping to Fusarium species over the last 20 years.…”

Molecular and Immunological Methods to Confirm Toxiginicity (Microcystin Production) of Westiellopsis Prolifica Isolated from Tigris River – Iraq

“…However, the expression increased significantly (P≤0.01) at the 3 rd week of growth (190 thousands folds increase) in comparison to the earlier times of the growth. There researchers investigated relationships between the proportion of mcy-genotypes in the population of cyanobacteria and the concentrations of microcystins in waters (21). W. prolific belongs to Nostocales, an order that includes species commonly found in tropical, subtropical and thermophilic habitats (22).…”