Using Microcystin Gene Copies to Determine Potentially-Toxic Blooms, Example from a Shallow Eutrophic Lake Peipsi

Abstract

Global warming, paired with eutrophication processes, is shifting phytoplankton communities towards the dominance of bloom-forming and potentially toxic cyanobacteria. The ecosystems of shallow lakes are especially vulnerable to these changes. Traditional monitoring via microscopy is not able to quantify the dynamics of toxin-producing cyanobacteria on a proper spatio-temporal scale. Molecular tools are highly sensitive and can be useful as an early warning tool for lake managers. We quantified the potential microcystin (MC) producers in Lake Peipsi using microscopy and quantitative polymerase chain reaction (qPCR) and analysed the relationship between the abundance of the mcyE genes, MC concentration, MC variants and toxin quota per mcyE gene. We also linked environmental factors to the cyanobacteria community composition. In Lake Peipsi, we found rather moderate MC concentrations, but microcystins and microcystin-producing cyanobacteria were widespread across the lake. Nitrate (NO3−) was a main driver behind the cyanobacterial community at the beginning of the growing season, while in late summer it was primarily associated with the soluble reactive phosphorus (SRP) concentration. A positive relationship was found between the MC quota per mcyE gene and water temperature. The most abundant variant—MC-RR—was associated with MC quota per mcyE gene, while other MC variants did not show any significant impact.

Microbial water quality in pangasius and tilapia aquaculture systems in five regions of Bangladesh

“…A positive correlation between mcyE copy numbers and concentrations of microcystin in plankton cells was observed by Falcone-Dias et al (2020) in Brazilian fish farms, as well as in a shallow temperate lake by Panksep et al (2020) (observed for microcystin RR only) and in lakes in Iowa, USA, by Lee et al (2020) (only the mcyA gene was studied). Thus, although microcystin only was measured in selected ponds in this study, the wide occurrence of the mcyE gene suggests that microcystin was present in phytoplankton cells and might be released to the water.…”

Understanding and predicting harmful algal blooms in a changing climate: A trait‐based framework

“…In addition to traditional ways of measuring traits (laboratory experiments), we need to develop new approaches, such as inferring traits that can be used in predictive models from the 'omic (genomic, transcriptomic, proteomic, and metabolomic) data (Hennon and Dyhrman 2020; Strzepek et al 2022) or the environmental distribution data using machine learning or similar techniques (Newman and Furbank 2021). Using genomic information to predict the toxic potential of the blooms is widespread (Janse et al 2004; Brunson et al 2018; Panksep et al 2020), but inferring other traits such as growth rates or nutrient uptake is much more complicated. The 'omic approaches are being increasingly used to characterize the responses of different HAB species and strains to environmental conditions, which may aid HAB predictions (Hennon and Dyhrman 2020).…”

Gill Junction Injury and Microbial Disorders Induced by Microcystin-Leucine Arginine in Lithobates catesbeianus Tadpoles

“…Among them, microcystin-leucine arginine (MC-LR) is the most widely distributed in freshwater, accounting for 46% to 99.8% of total microcystins [ 18 , 19 ]. A survey of 134 lakes in New Zealand found that the highest concentration of microcystins was 6.4 μg/L [ 20 ]. In 29 pond/ditch drinking water samples collected in Nanning District, Guangxi, China, the average MC-LR concentration was 0.5 μg/L [ 21 ].…”