Variation in peptide net production and growth among strains of the toxic cyanobacterium<b><i>Planktothrix</i></b>spp.

Kosol, Simone; Schmidt, Johanna; Kurmayer, Rainer

doi:10.1080/09670260802158659

Cited by 42 publications

(41 citation statements)

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“…In order to elucidate the influence of the genetic diversity among A domains on AP structure variation, we compared the A domains of the apn gene cluster among seven Planktothrix sp. strains that differ in AP production in that they contain AP metabolites with Arg only or with either Arg or Tyr in exocylic position 1 (22). In contrast to the findings for the apt gene cluster from Anabaena strain 90 (39), we found no evidence for duplication of a bimodular protein carrying two alternative initiation modules that could explain the co-occurrence of AP metabolites bearing Arg or Tyr in exocylic position 1.…”

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confidence: 56%

Genetic Variation of Adenylation Domains of the Anabaenopeptin Synthesis Operon and Evolution of Substrate Promiscuity

et al. 2011

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confidence: 56%

Genetic Variation of Adenylation Domains of the Anabaenopeptin Synthesis Operon and Evolution of Substrate Promiscuity

et al. 2011

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“…The 'average' density-based P. rubescens cell quota determined in this study were in the range of other values reported in literature (Naselli-Flores et al, 2007;Briand et al, 2008;Kosol et al, 2009;Manganelli et al, 2010Manganelli et al, , 2016. Interestingly, the cell quota determined for M. botrys were constantly about 10 times higher than P. rubescens and in the range of Microcystis cell quota in the field estimated by Yu et al (2014) (0.001 and 1.326 pg cell -1 on the whole population and 0.012 and 1.876 pg cell -1 on the toxic cells).…”

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confidence: 70%

Cyanobacterial dynamics and toxins concentrations in Lake Alto Flumendosa, Sardinia, Italy

et al. 2017

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Seasonal blooms of cyanobacteria (CB) are a typical feature of Lake Alto Flumendosa (Sardinia, Italy). The waters of this lake are used for drinking water supply, for agricultural and industrial uses, and fish farming activities. Since cyanotoxins are not monitored in edible organisms, diet could be a relevant route of human exposure. CB also represent a threat for the health of wild and domestic animals that use lake water for beverage. Therefore, to characterize the CB community and assess the risk for human and animal population, CB dynamic, mcyB+ fraction, and microcystins (MCs) concentration have been followed monthly for 18 months, in three stations. Results confirmed the presence of several toxigenic species. Planktothrix rubescens dominated between August 2011 and April 2012 (3.5×106 cells L-1), alternating with Woronichinia naegeliana (8×106 cells L-1) and Microcystis botrys (9×105 cells L-1). Dolichospermum planctonicum was always present at low densities (104 cells L-1). MCs were detected, at values well below the 1 µg L-1 threshold of WHO for drinking water. The molecular analysis of mcyB gene for P. rubescens indicated the presence of a persistent toxic population (average 0.45 mcyB/16S rDNA). Highly significant linear regressions were found between P. rubescens and the sum of the demethylated MC variants, and between M. botrys and the sum of MC-LR and MC-LA, also when co-occurring, suggesting that these two species were responsible for different MC patterns production. The regression lines indicated a quite stable MC cell quota. However, in some spotted samples very different values were obtained for both MC concentrations and cell quota (from 10-fold lower to 30-40-fold higher than the ‘average’) showing an unexpected significant variability in the rate of toxin production. The relatively low cell densities during the monitoring period is consistent with the low-to absent MC contamination level found in trout muscle; however, the analytical method was affected by low recovery, probably due to MC-protein binding. Our results show that, during the study period, no risk of exposure for the human and animal population occurred. However, the persistence of a complex CB community characterised by a significant toxic fraction suggests the need for periodic monitoring activity. Particularly, the hidden deep summer P. rubescens blooms, located where water is taken for drinking water supply, and M. botrys, able to produce the most toxic MC variants with high cell quota, should be kept under control. The documentation and interpretation of sudden changes in toxins concentrations deserve special attention. This is particularly relevant in proximity of fish farming plants and water catchment sites.

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“…3A), a biovolume of 10 mm 3 liter Ϫ1 of microcystin genotypes corresponds to a microcystin concentration of 62.3 Ϯ 1 g (confidence interval, 45.8 to 84.8 g) microcystin-LR equivalents. Since microcystin-producing strains of Microcystis and Planktothrix do not differ principally in their microcystin contents (20), such a regression curve may also be applicable to water samples that are dominated by Microcystis. While for both taxa, comparable ranges of cellular microcystin contents have been reported (e.g., see data in reference 49 versus data in reference 46), we hereby emphasize, however, that the applicability of the regression curve (Fig.…”

Section: Discussionmentioning

confidence: 99%

Application of Real-Time PCR To Estimate Toxin Production by the Cyanobacterium Planktothrix sp

Ostermaier

Kurmayer

2010

Appl Environ Microbiol

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Quantitative real-time PCR methods are increasingly being applied for the enumeration of toxic cyanobacteria in the environment. However, to justify the use of real-time PCR quantification as a monitoring tool, significant correlations between genotype abundance and actual toxin concentrations are required. In the present study, we aimed to explain the concentrations of three structural variants of the hepatotoxin microcystin ( During the last decade, genetic methods have significantly increased our understanding of the distribution of genes that are involved in the production of toxins within cyanobacteria that occur in fresh and brackish water (45). Although genetic methods can indicate only the potential risk of toxin synthesis and do not provide information about the actual toxin concentrations, quantitative real-time PCR has been increasingly applied for monitoring the toxin-producing genotypes of cyanobacteria in water (26,33,44). The development of real-time PCR methods was driven primarily by its potential (i) as an early-warning tool as well as to monitor toxin-producing cyanobacteria and (ii) to identify those factors that lead to a dominance/repression of toxin-producing genotypes versus nontoxic genotypes. For the first aim, it is essential that the abundance of toxin-producing cyanobacteria can be related to the concentration of the respective toxic substance in water. A few studies showed that the concentration of certain toxic genotypes was linearly related to the respective toxin concentrations, e.g., for the most common group of hepatotoxins, the microcystins (MCs) (7,12,14), and for the related nodularin (19). Both microcystins and nodularins are known to be potent inhibitors of eukaryotic protein phosphatases 1 and 2A, resulting in a health hazard to humans and the environment (9). In contrast, no correlation was found (37, 50), or even the opposite was reported, by other studies, i.e., that the measurement of microcystin-producing genotypes is not a satisfactory method for use in monitoring programs in order to predict the toxic risk associated with cyanobacterial proliferation (3). For microcystins, these contrasting results may be due to several reasons: (i) several genera producing microcystins frequently coexist in water bodies, and therefore, not all microcystin producers may have been identified; (ii) the semilogarithmic calibration curves limit the accuracy in estimations of genotype numbers and proportions (for example, the only laboratory comparison carried out so far revealed that among the three laboratories tested, the proportions of toxic genotypes were overestimated or underestimated by 0 to 72% and 0 to 50%, respectively [42]); and (iii) inactive mutants that contain the respective genes, however, which have been inactivated in toxin production through the insertion of transposable elements, may co-occur and decrease toxin production in a given population (6). Nevertheless, the real-time PCR technique is the only quantitative technique available for estimating the proportion of...

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Variation in peptide net production and growth among strains of the toxic cyanobacteriumPlanktothrixspp.

Cited by 42 publications

References 40 publications

Genetic Variation of Adenylation Domains of the Anabaenopeptin Synthesis Operon and Evolution of Substrate Promiscuity

Genetic Variation of Adenylation Domains of the Anabaenopeptin Synthesis Operon and Evolution of Substrate Promiscuity

Cyanobacterial dynamics and toxins concentrations in Lake Alto Flumendosa, Sardinia, Italy

Application of Real-Time PCR To Estimate Toxin Production by the Cyanobacterium Planktothrix sp

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