scholarly journals 5 Potential effects of climate change on cyanobacterial toxin production

2020 ◽  
pp. 167-194
Keyword(s):  
Climate Change ◽  
Toxin Production ◽  
Cyanobacterial Toxin

scholarly journals Cyanobacterial Toxin Degrading Bacteria: Who Are They?

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Konstantinos Ar. Kormas ◽  
Despoina S. Lymperopoulou
Keyword(s):  
Meta Analysis ◽  
Toxin Production ◽  
Cyanobacterial Blooms ◽  
Ecological Knowledge ◽  
Cyanobacterial Toxin ◽  
Molecular Approaches ◽  
Degrading Bacteria ◽  
Ecological Problems ◽  
Ecosystem Level ◽  
Toxin Degradation

Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA andmlrA(microcystinase) genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of theMethylobacillusandPaucibactergenera. Other strains belonged to the generaArthrobacter, Bacillus, andLactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.

scholarly journals Impact of interacting climate change factors on growth and ochratoxin A production by Aspergillus section Circumdati and Nigri species on coffee

2016 ◽  
Vol 9 (5) ◽  
pp. 863-874 ◽  
Author(s):  
A. Akbar ◽  
A. Medina ◽  
N. Magan
Keyword(s):  
Climate Change ◽  
Ochratoxin A ◽  
Toxin Production ◽  
Aspergillus Ochraceus ◽  
Change Factors ◽  
Significant Stimulation ◽  
Coffee Beans ◽  
Higher Temperature ◽  
Stimulation Of ◽  
Lag Phases

The objectives of this study were to evaluate the effect of interacting climate change (CC) factors (water stress [water activity, aw; 0.99-0.90]); temperature [30, 35 °C]; and elevated CO2 [400 and 1000 ppm] on (1) lag phases prior to growth, (2) growth and (3) ochratoxin A (OTA) production by species of Aspergillus sections Circumdati and Nigri on coffee-based media and stored coffee beans. The lag phases, prior to growth, of all strains/species were slightly increased as aw, temperature and CO2 were modified. The interacting CC factors showed that most strains/species examined grew well at 30 °C and slightly less so at 35 °C except for Aspergillus niger (A 1911) which could tolerate the higher temperature. In addition, the interaction of elevated CO2 (1000 ppm) + temperature (35 °C) increased OTA production when compared with 30 °C but only for strains of Aspergillus westerdijkiae (B2), Aspergillus ochraceus (ITAL 14) and Aspergillus steynii (CBS 112814). Most of the strains had optimum growth at 0.95 aw at 35 °C, while at 30 °C the optimum was at 0.98 aw. On stored coffee beans there was only a significant stimulation of OTA production by A. westerdijkiae strains in elevated CO2 (1000) at 0.90 aw. These results suggest differential effects of CC factors on OTA production by species in the Sections Circumdati and Nigri in stored coffee and that for most species there is a reduction in toxin production.

Use of functional genomics to assess the climate change impact on Aspergillus flavus and aflatoxin production

2016 ◽  
Vol 9 (5) ◽  
pp. 665-672 ◽  
Author(s):  
M.K. Gilbert ◽  
B.M. Mack ◽  
G.A. Payne ◽  
D. Bhatnagar
Keyword(s):  
Climate Change ◽  
Functional Genomics ◽  
Aspergillus Flavus ◽  
Pathogenic Fungus ◽  
Regulatory Gene ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Transcriptomic Response ◽  
Climate Conditions ◽  
Change Impact

Aspergillus flavus is an opportunistic and pathogenic fungus that infects several crops of agricultural importance and under certain conditions may produce carcinogenic mycotoxins. Rising global temperatures, disrupted precipitation patterns and increased CO2 levels that are associated with future climate conditions are expected to impact the growth and toxigenic potential of A. flavus. Both laboratory and real world observations have demonstrated this potential, especially when examining the effects of water availability and temperature. Recent experiments have also established that CO2 may also be affecting toxin production. The application of current technologies in the field of functional genomics, including genomic sequencing, RNA-seq, microarray technologies and proteomics have revealed climate change-related, abiotic regulation of the aflatoxin cluster and influence on the plant-fungus interaction. Furthermore, elevated CO2 levels have been shown to impact expression of the aflatoxin biosynthetic regulatory gene aflR. The use of functional genomics will allow researchers to better understand the underlying transcriptomic response within the fungus to climate change, with a view towards predicting changes in fungal infection and toxin production associated with climate change.

scholarly journals Managing cyanobacterial toxin risks to recreational users: a case study of inland lakes in South East Queensland

2017 ◽  
Vol 18 (5) ◽  
pp. 1719-1726
Author(s):  
Cameron James Veal ◽  
Catherine Neelamraju ◽  
T. Wolff ◽  
A. Watkinson ◽  
D. Shillito ◽  
...  
Keyword(s):  
Management Practice ◽  
Water Quality Management ◽  
Toxin Production ◽  
Cylindrospermopsis Raciborskii ◽  
Management Approach ◽  
Inland Waterways ◽  
Cyanobacterial Toxin ◽  
Inland Lakes ◽  
Cell Counts ◽  
Guideline Values

Abstract The management of inland waterways to protect recreational users from cyanotoxin exposure is complicated by the common management practice of using proxy indicators of cyanotoxin production (cell counts and biovolumes of potentially toxin species), rather than the cyanotoxin itself. This widely accepted practice is further complicated by a lack of advisory guidelines for non-microcystin-producing cyanotoxins. This study has investigated the effectiveness of this management approach over five and a half years, monitoring 65 different sites in South East Queensland using phycological and toxin-analysis. This study concluded that cell counts of Cylindrospermopsis raciborskii, the most common potentially toxin producing species of cyanobacteria in South East Queensland's inland lakes, was a poor proxy indicator for cylindrospermopsin toxin production. Seqwater, the local water authority responsible for the management of recreational access to drinking water storage lakes, initiated an alternative management approach for recreational cyanobacterial water quality management in December 2016. This new approach is based on cyanobacterial toxin guideline values for five different cyanotoxins, with closures and warning notices issued based on the actual cyanotoxin concentration, not the proxy indicator. We encourage other recreational water management authorities consider this approach to manage recreational access in the future.

Cyanobacterial Toxins in Water

1989 ◽  
Vol 21 (3) ◽  
pp. 1-13 ◽  
Author(s):  
Geoffrey A. Codd ◽  
Steven G. Bell ◽  
William P. Brooks
Keyword(s):  
Drinking Water ◽  
Natural Waters ◽  
Biological Significance ◽  
Industrial Effluents ◽  
Toxin Production ◽  
Immunological Methods ◽  
Mouse Bioassay ◽  
Cyanobacterial Toxins ◽  
Blue Green Algae ◽  
Cyanobacterial Toxin

Cyanobacteria (blue-green algae) commonly occur in fresh- and brackish waters and may produce massive annual growths as a consequence of nutrient enrichment from natural waters, agricultural fertilizer run-off, or from domestic/industrial effluents. The cyanobacterial species which dominate these growths typically belong to the genera which produce toxins. Cyanobacterial toxins cause fatal poisonings of agricultural livestock, wild animals, birds and fish on a world-wide basis. The involvement of the toxins in human health problems has also been inferred in several countries and their presence in drinking water sources is of interest to the drinking water industry. The occurrence and properties of cyanobacterial toxins are discussed here. New methods are being developed for the purification of the toxins and for their recovery and quantification from waters. These include the use of chemical, cytotoxicity and immunological methods to complement the mouse bioassay which has hitherto been used in cyanobacterial toxin studies with laboratory cultures and water samples. Information on the regulation of cyanobacterial toxin production and on the possible biological significance of the toxins in aquatic environments is also presented. A greater awareness of cyanobacterial toxins in waters destined for human use is required.

scholarly journals Microbial diversity and toxin risk in tropical freshwater reservoirs of Cape Verde

2018 ◽  
Author(s):  
Ana P. Semedo-Aguiar ◽  
José B. Pereira-Leal ◽  
Ricardo B. Leite
Keyword(s):  
Microbial Diversity ◽  
Global Climate ◽  
Amplicon Sequencing ◽  
Toxin Production ◽  
Cape Verde ◽  
Cyanobacterial Blooms ◽  
Rrna Gene ◽  
Water Reservoirs ◽  
Cyanobacterial Toxin ◽  
Close Relationship

AbstractThe Cape Verde islands are part of the African Sahelian arid belt that possesses an irregular rainy season between August and October. This erratic rain pattern has prompted the need for water reservoirs, now critical for the country’s sustainability. Worldwide, freshwater cyanobacterial blooms are increasing in frequency due to global climate change and eutrophication of water bodies, particularly in reservoirs. To date there have been no risk assessments of cyanobacterial toxin production in these man-made structures. We evaluated this potential risk using 16S rRNA gene amplicon sequencing and full metagenome sequencing in freshwater reservoirs of Cape Verde.Our analysis revealed the presence of several potentially toxic cyanobacterial genera in all sampled reservoirs (Poilão, Saquinho and Faveta). In Faveta Microcystis sp., a genus well known for toxin production and bloom-formation, dominated our samples, while a green algae of the genus Cryptomonas and Gammaproteobacteria dominated Saquinho and Poilão.Taking advantage of the dominance of Microcystis in the Faveta reservoir, we were able to reconstruct and assemble its genome, extracted from a metagenome of bulk DNA from Faveta water. We named it Microcystis cf. aeruginosa CV01, for which a phylogenetic analysis revealed to have a close relationship with other genomes from those taxa, as well as other continental African strains, suggesting geographical coherency. In addition, it revealed several clusters of known toxin-producing genes. This assessment of Cape Verdean freshwater microbial diversity and potential for toxin production reinforces the need to better understand the microbial ecology as a whole of water reservoirs on the rise.

Averting robo-bees: why free-flying robotic bees are a bad idea

2019 ◽  
Vol 3 (6) ◽  
pp. 723-729
Author(s):  
Roslyn Gleadow ◽  
Jim Hanan ◽  
Alan Dorin
Keyword(s):  
Climate Change ◽  
Computer Simulation ◽  
Food Security ◽  
European Countries ◽  
Plant Interactions ◽  
Plant Insect Interactions ◽  
Native Habitat ◽  
Insect Pollinators ◽  
Insect Interactions

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.

Sign in / Sign up

Export Citation Format

Share Document