scholarly journals Anabaenopeptins from Cyanobacteria in Freshwater Bodies of Greece

Toxins ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 4
Author(s):  
Sevasti-Kiriaki Zervou ◽  
Triantafyllos Kaloudis ◽  
Spyros Gkelis ◽  
Anastasia Hiskia ◽  
Hanna Mazur-Marzec
Keyword(s):  
Mass Spectra ◽  
Cyanobacterial Blooms ◽  
Bioactive Metabolites ◽  
Cyanobacterial Strain ◽  
Structural Variety ◽  
Freshwater Bodies ◽  
Photosynthetic Microorganisms ◽  
Time Periods ◽  
Favorable Conditions ◽  
Of Greece

Cyanobacteria are photosynthetic microorganisms that are able to produce a large number of secondary metabolites. In freshwaters, under favorable conditions, they can rapidly multiply, forming blooms, and can release their toxic/bioactive metabolites in water. Among them, anabaenopeptins (APs) are a less studied class of cyclic bioactive cyanopeptides. The occurrence and structural variety of APs in cyanobacterial blooms and cultured strains from Greek freshwaters were investigated. Cyanobacterial extracts were analyzed with LC–qTRAP MS/MS using information-dependent acquisition in enhanced ion product mode in order to obtain the fragmentation mass spectra of APs. Thirteen APs were detected, and their possible structures were annotated based on the elucidation of fragmentation spectra, including three novel ones. APs were present in the majority of bloom samples (91%) collected from nine Greek lakes during different time periods. A large variety of APs was observed, with up to eight congeners co-occurring in the same sample. AP F (87%), Oscillamide Y (87%) and AP B (65%) were the most frequently detected congeners. Thirty cyanobacterial strain cultures were also analyzed. APs were only detected in one strain (Microcystis ichtyoblabe). The results contribute to a better understanding of APs produced by freshwater cyanobacteria and expand the range of structurally characterized APs.

Dynamics of the prokaryotic and eukaryotic microbial community during a cyanobacterial bloom

2021 ◽  
Author(s):  
Yilin Qian ◽  
Kunihiro Okano ◽  
Miwa Kodato ◽  
Michiko Arai ◽  
Takeru Yanagiya ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Negative Correlation ◽  
Aquatic Environment ◽  
Cyanobacterial Bloom ◽  
Cyanobacterial Blooms ◽  
Gene Copy ◽  
Degrading Bacteria ◽  
Freshwater Bodies ◽  
Predator Community

Abstract Toxic cyanobacterial blooms frequently develop in eutrophic freshwater bodies worldwide. Microcystis species produce microcystins (MCs) as a cyanotoxin. Certain bacteria that harbor the mlr gene cluster, especially mlrA, are capable of degrading MCs. However, MCs-degrading bacteria may possess or lack mlr genes (mlr+ and mlr− genotypes, respectively). In this study we investigated the genotype that predominantly contributes to biodegradation and cyanobacterial predator community structure with change in total MCs concentration in an aquatic environment. The two genotypes co-existed but mlr+ predominated, as indicated by the negative correlation between mlrA gene copy abundance and total MCs concentration. At the highest MCs concentrations, predation pressure by Phyllopoda, Copepoda, and Monogononta (rotifers) was reduced; thus, MCs may be toxic to cyanobacterial predators. The results suggest cooperation between MCs-degrading bacteria and predators may reduce Microcystis abundance and MCs concentration.

scholarly journals MMHub, a database for the mulberry metabolome

Database ◽  
2020 ◽  
Vol 2020 ◽  
Author(s):  
Dong Li ◽  
Bi Ma ◽  
Xiaofei Xu ◽  
Guo Chen ◽  
Tian Li ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Chemical Compounds ◽  
Bioactive Metabolites ◽  
Molecular Formula ◽  
Experimental Conditions ◽  
Chemical Structures ◽  
Pubchem Compound ◽  
Specific Distribution ◽  
Small Chemical ◽  
Metabolome Data

Abstract Mulberry is an important economic crop plant and traditional medicine. It contains a huge array of bioactive metabolites such as flavonoids, amino acids, alkaloids and vitamins. Consequently, mulberry has received increasing attention in recent years. MMHub (version 1.0) is the first open public repository of mass spectra of small chemical compounds (<1000 Da) in mulberry leaves. The database contains 936 electrospray ionization tandem mass spectrometry (ESI-MS2) data and lists the specific distribution of compounds in 91 mulberry resources with two biological duplicates. ESI-MS2 data were obtained under non-standardized and independent experimental conditions. In total, 124 metabolites were identified or tentatively annotated and details of 90 metabolites with associated chemical structures have been deposited in the database. Supporting information such as PubChem compound information, molecular formula and metabolite classification are also provided in the MS2 spectral tag library. The MMHub provides important and comprehensive metabolome data for scientists working with mulberry. This information will be useful for the screening of quality resources and specific metabolites of mulberry. Database URL: https://biodb.swu.edu.cn/mmdb/

New bioactive metabolites from Penicillium purpurogenum MM

2016 ◽  
Vol 71 (4) ◽  
pp. 287-295 ◽  
Author(s):  
Mohamed Shaaban ◽  
Mohammad Magdy El-Metwally ◽  
Hartmut Laatsch
Keyword(s):  
Mass Spectra ◽  
Dimethyl Acetal ◽  
Bioactive Metabolites ◽  
Cytotoxic Activities ◽  
Penicillium Purpurogenum ◽  
Chemical Structures ◽  
Ergosterol Peroxide ◽  
New Compounds ◽  
Taxonomic Characterization

AbstractThree new bioactive compounds, namely (S)-tenellic acid B dimethyl acetal (1a), (3R,3′R/S)-isotalarone (2), and (3R,5R)-cis-5-methyl-3-(2-oxobutyl)-dihydrofuran-2-one (3), were isolated from the terrestrial fungus Penicillium purpurogenum MM, together with 15 known metabolites: talaroflavone, pestalasin A, altenuene, penicillide, 3′-O-methyl-dehydroisopenicillide, rubralactone, tenellic acid B, diaporthin, butyrolactone 1, butyrolactone-V, 4-hydroxy-2-methoxyacetanilide, ergosterol, ergosterol peroxide, linoleic acid, and glycerol monolinoleate. The chemical structures of the three new compounds were confirmed by extensive one- and two-dimensional NMR and electron spray ionization high-resolution mass spectra measurements and by comparison with literature data. The absolute configurations of the new compounds, and of talaroflavone (4a) and tenellic acid B (2b), were determined by ab initio calculations of ECD, ORD, and NMR data. The antimicrobial and cytotoxic activities of the crude extract and of the isolated compounds were studied using a set of microorganisms and brine shrimp assay, respectively. The isolation and taxonomic characterization of P. purpurogenum MM is reported.

scholarly journals The influence of nitrogen and growth phase on the toxicity of the cyanobacterial strain Microcystis PCC 7806

2019 ◽  
pp. 89-100
Author(s):  
Petar Davidovic ◽  
Dajana Blagojevic ◽  
Olivera Babic ◽  
Jelica Simeunovic
Keyword(s):  
Growth Phase ◽  
Larval Mortality ◽  
Artemia Salina ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
High Dose ◽  
Toxic Metabolite ◽  
Cyanobacterial Strain ◽  
Test Organisms ◽  
Nitrogen Concentrations

The worldwide occurrence of toxic cyanobacterial blooms and their numerous harmful effects have instigated extensive research into the environmental conditions promoting such events. Among the environmental factors which have been suggested to influence the increase in cyanobacterial proliferation, nutrient levels have been identified as one of the most prominent, affecting the growth and toxic metabolite production of cyano?bacteria in freshwater ecosystems. In the present study, toxicity of the cyanobacterial strain Microcystis PCC 7806 was evaluated after growth in media with three different nitrogen concentrations. The toxicity of intracellular extracts was analyzed during different growth phases (after 7, 21, and 35 days of cultivation) by observing mortality rates in the Artemia salina bioassay after 24h and 48h of exposure. The results have not shown significantly higher mortality levels between the test organisms exposed to extracts obtained from the cultures grown in the presence of higher nitrogen content (1.5 g/l and 0.8 g/l) and those grown in a nitrogen-free medium. A dose dependent effect, however, can be observed in most cases, with the most substantial changes observed in the high-dose groups. Also, the toxic effects and larval mortality increased during the exposure, suggesting the time-dependent toxicity. Extracts obtained after longer periods of cultivation (21 and 35 days) had stronger effects on the test organisms, which indicates that the toxicity of the tested cyanobacterial strain depends on the specific growth phase.

scholarly journals A chemophenetic study of the genus Maytenus s.l. (Celastraceae): contribution to the rational search of its bioactive metabolites

Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Lorena Diniz Guimarães ◽  
Fernanda Moreira do Amaral ◽  
Natalia Barros dos Santos ◽  
Ana Joffily ◽  
Maria Carolina Anholeti ◽  
...  
Keyword(s):  
Biological Activities ◽  
New Drugs ◽  
Quinone Methide ◽  
Bioactive Metabolites ◽  
Quinone Methides ◽  
Multiple Functions ◽  
Structural Variety ◽  
Plant Groups ◽  
Antitumor Potential ◽  
Chemosystematic Markers

Abstract Maytenus s.l. is a genus of the Celastraceae family and many of its species are used in traditional medicine. Most of the substances responsible for the biological activities of plants come from their secondary metabolism, such as terpenoids and flavonoids, which have multiple functions in the plant and can occur in a similar way in plant groups. Chemophenetics analyzes the occurrence of these substances in a taxon and can infer evolutionary trends and contribute to the rational search for new drugs. Chemosystematic parameters were used to analyze the data obtained through a bibliographic survey. The species of Maytenus s.l. were separated into three groups: species with accepted names, synonymous species with the genus Monteverdia and synonymous species with the genus Gymnosporia. Due to their great occurrence and structural variety in Maytenus s.l., triterpenes were chosen as chemosystematic markers, with friedelanes and quinone methide triterpenes being the most expressive types. Studies have already demonstrated the analgesic potential of quinone methides and the antitumor potential of phenolic triterpenes and dimers of these units. Together, the three classes assist in the circumscription of Maytenus s.s. and Monteverdia, while lupanes can be used in the separation of these genera. Oleanans are representative of Gymnosporia.

scholarly journals Symphyonema bifilamentata sp. nov., the Right Fischerella ambigua 108b: Half a Decade of Research on Taxonomy and Bioactive Compounds in New Light

2021 ◽  
Vol 9 (4) ◽  
pp. 745
Author(s):  
Patrick Jung ◽  
Paul M. D’Agostino ◽  
Burkhard Büdel ◽  
Michael Lakatos
Keyword(s):  
Small Molecules ◽  
Bioactive Compounds ◽  
Bioactive Metabolites ◽  
Phylogenetic Position ◽  
Cyanobacterial Strain ◽  
Protein Coding ◽  
The Family ◽  
True Branching Cyanobacteria ◽  
The Right ◽  
True Branching

Since 1965 a cyanobacterial strain termed ‘Fischerella ambigua 108b’ was the object of several studies investigating its potential as a resource for new bioactive compounds in several European institutes. Over decades these investigations uncovered several unique small molecules and their respective biosynthetic pathways, including the polychlorinated triphenyls of the ambigol family and the tjipanazoles. However, the true taxonomic character of the producing strain remained concealed until now. Applying a polyphasic approach considering the phylogenetic position based on the 16S rRNA and the protein coding gene rbcLX, secondary structures and morphological features, we present the strain ‘Fischerella ambigua 108b’ as Symphyonema bifilamentata sp. nov. 97.28. Although there is the type species (holotype) S. sinense C.-C. Jao 1944 there is no authentic living strain or material for genetic analyses for the genus Symphyonema available. Thus we suggest and provide an epitypification of S. bifilamentata sp. nov. 97.28 as a valid reference for the genus Symphyonema. Its affiliation to the family Symphyonemataceae sheds not only new light on this rare taxon but also on the classes of bioactive metabolites of these heterocytous and true-branching cyanobacteria which we report here. We show conclusively that the literature on the isolation of bioactive products from this organism provides further support for a clear distinction between the secondary metabolism of Symphyonema bifilamentata sp. nov. 97.28 compared to related and other taxa, pointing to the assignment of this organism into a separate genus.

scholarly journals Potentially Toxic Planktic and Benthic Cyanobacteria in Slovenian Freshwater Bodies: Detection by Quantitative PCR

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 133
Author(s):  
Maša Zupančič ◽  
Polona Kogovšek ◽  
Tadeja Šter ◽  
Špela Remec Rekar ◽  
Leonardo Cerasino ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Water Bodies ◽  
Cyanobacterial Blooms ◽  
Threat Detection ◽  
Gene Copies ◽  
Toxic Cyanobacteria ◽  
Freshwater Bodies ◽  
Mcye Gene ◽  
One Year ◽  
Reliable Methods

Due to increased frequency of cyanobacterial blooms and emerging evidence of cyanotoxicity in biofilm, reliable methods for early cyanotoxin threat detection are of major importance for protection of human, animal and environmental health. To complement the current methods of risk assessment, this study aimed to evaluate selected qPCR assays for detection of potentially toxic cyanobacteria in environmental samples. In the course of one year, 25 plankton and 23 biofilm samples were collected from 15 water bodies in Slovenia. Three different analyses were performed and compared to each other; qPCR targeting mcyE, cyrJ and sxtA genes involved in cyanotoxin production, LC-MS/MS quantifying microcystin, cylindrospermopsin and saxitoxin concentration, and microscopic analyses identifying potentially toxic cyanobacterial taxa. qPCR analyses detected potentially toxic Microcystis in 10 lake plankton samples, and potentially toxic Planktothrix cells in 12 lake plankton and one lake biofilm sample. A positive correlation was observed between numbers of mcyE gene copies and microcystin concentrations. Potential cylindrospermopsin- and saxitoxin-producers were detected in three and seven lake biofilm samples, respectively. The study demonstrated a potential for cyanotoxin production that was left undetected by traditional methods in both plankton and biofilm samples. Thus, the qPCR method could be useful in regular monitoring of water bodies to improve risk assessment and enable timely measures.

scholarly journals Effects of Cyanobacterial Toxins on the Human Gastrointestinal Tract and the Mucosal Innate Immune System

2019 ◽  
Author(s):  
Barbara Kubíčková ◽  
Pavel Babica ◽  
Klára Hilscherova ◽  
Lenka Šindlerová
Keyword(s):  
Drinking Water ◽  
Immune System ◽  
Gastrointestinal Tract ◽  
Clinical Symptoms ◽  
Cyanobacterial Bloom ◽  
Gastrointestinal Symptoms ◽  
Epidemiological Studies ◽  
Cyanobacterial Blooms ◽  
Bioactive Metabolites ◽  
Carcinogenic Potential

Cyanobacterial blooms occur with increasing frequency in freshwater ecosystems, posing a hazard to human and environmental health. Exposure of human to cyanobacterial metabolites occurs mostly via accidental ingestion through contaminated drinking water or during recreational activities and, most frequently, results in gastrointestinal symptoms. Despite the clinical manifestation, cyanobacterial metabolites are rather investigated for their toxicity towards specific organs or tissues, especially hepato-, nephro- and neurotoxicity, then for effects on the gastrointestinal tract and the associated lymphoid tissue. The aim of this review was to systematically summarize available literature on the effects on the gastrointestinal tract and the mucosal innate immune system and compile the data from both, in vitro and in vivo studies, focusing on human-health relevant models. Our systematic literature review revealed significant data gaps in the understanding on metabolites breaching the gastrointestinal barrier and the role of the immune system in the establishment of clinical symptoms. Microcystins and cylindrospermopsin were linked to gastrointestinal symptoms, immune system effects or both. Furthermore, implications for cyanobacterial bloom lipopolysaccharides in gastrointestinal inflammation were reported in several cases, while other metabolites received only minor attention. The collected data indicate the need for a reassessment of potential enterotoxicity of microcystins and cylindrospermopsin. Additionally, the carcinogenic potential of cyanotoxins, especially microcystins, has to be clarified, as an increasing amount of epidemiological studies show correlations between cyanobacterial blooms and gastrointestinal cancer incidence. Furthermore, other, often highly abundant bioactive metabolites like aeruginosins, have to be toxicologically evaluated at levels also accounting for (sub-)chronic exposure to low concentrations and in combination with naturally co-occurring metabolites, as can be expected in drinking water supplies. studies, focusing on human-health relevant models. Our systematic literature review revealed significant data gaps in the understanding on metabolites breaching the gastrointestinal barrier and the role of the immune system in the establishment of clinical symptoms. Microcystins and cylindrospermopsin were linked to gastrointestinal symptoms, immune system effects or both. Furthermore, implications for cyanobacterial bloom lipopolysaccharides in gastrointestinal inflammation were reported in several cases, while other metabolites received only minor attention. The collected data indicate the need for a reassessment of potential enterotoxicity of microcystins and cylindrospermopsin. Additionally, the carcinogenic potential of cyanotoxins, especially microcystins, has to be clarified, as an increasing amount of epidemiological studies show correlations between cyanobacterial blooms and gastrointestinal cancer incidence. Furthermore, other, often highly abundant bioactive metabolites like aeruginosins, have to be toxicologically evaluated at levels also accounting for (sub-)chronic exposure to low concentrations and in combination with naturally co-occurring metabolites, as can be expected in drinking water supplies.

scholarly journals Suppressing Cyanobacteria with Hydrogen Peroxide Is More Effective at High Light Intensities

Toxins ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 18 ◽  
Author(s):  
Tim Piel ◽  
Giovanni Sandrini ◽  
Emily White ◽  
Tianshuo Xu ◽  
J. Merijn Schuurmans ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drinking Water ◽  
Photosystem Ii ◽  
Cell Size ◽  
Environmental Parameters ◽  
High Light ◽  
Cyanobacterial Blooms ◽  
Cyanobacterial Strain ◽  
Low Light ◽  
Light Intensities

Hydrogen peroxide (H2O2) can be used as an emergency method to selectively suppress cyanobacterial blooms in lakes and drinking water reservoirs. However, it is largely unknown how environmental parameters alter the effectiveness of H2O2 treatments. In this study, the toxic cyanobacterial strain Microcystis aeruginosa PCC 7806 was treated with a range of H2O2 concentrations (0 to 10 mg/L), while being exposed to different light intensities and light colors. H2O2 treatments caused a stronger decline of the photosynthetic yield in high light than in low light or in the dark, and also a stronger decline in orange than in blue light. Our results are consistent with the hypothesis that H2O2 causes major damage at photosystem II (PSII) and interferes with PSII repair, which makes cells more sensitive to photoinhibition. Furthermore, H2O2 treatments caused a decrease in cell size and an increase in extracellular microcystin concentrations, indicative of leakage from disrupted cells. Our findings imply that even low H2O2 concentrations of 1–2 mg/L can be highly effective, if cyanobacteria are exposed to high light intensities. We therefore recommend performing lake treatments during sunny days, when a low H2O2 dosage is sufficient to suppress cyanobacteria, and may help to minimize impacts on non-target organisms.

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