scholarly journals Metagenomics Analysis to Investigate the Microbial Communities and Their Functional Profile During Cyanobacterial Blooms in Lake Varese

2021 ◽  
Author(s):  
Isabella Sanseverino ◽  
Patrizia Pretto ◽  
Diana Conduto António ◽  
Armin Lahm ◽  
Chiara Facca ◽  
...  
Keyword(s):  
Secchi Depth ◽  
Aquatic Organisms ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
Natural Phenomenon ◽  
Sequencing Analysis ◽  
Functional Profile ◽  
Microbial Composition ◽  
Taxonomic Profile ◽  
Prokaryotic Microorganisms

AbstractToxic cyanobacterial blooms represent a natural phenomenon caused by a mass proliferation of photosynthetic prokaryotic microorganisms in water environments. Bloom events have been increasingly reported worldwide and their occurrence can pose serious threats to aquatic organisms and human health. In this study, we assessed the microbial composition, with a focus on Cyanobacteria, in Lake Varese, a eutrophic lake located in northern Italy. Water samples were collected and used for obtaining a 16S-based taxonomic profile and performing a shotgun sequencing analysis. The phyla found to exhibit the greatest relative abundance in the lake included Proteobacteria, Cyanobacteria, Actinobacteriota and Bacteroidota. In the epilimnion and at 2.5 × Secchi depth, Cyanobacteria were found to be more abundant compared to the low levels detected at greater depths. The blooms appear to be dominated mainly by the species Lyngbya robusta, and a specific functional profile was identified, suggesting that distinct metabolic processes characterized the bacterial population along the water column. Finally, analysis of the shotgun data also indicated the presence of a large and diverse phage population.

scholarly journals A Brief Review of the Structure, Cytotoxicity, Synthesis, and Biodegradation of Microcystins

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2147
Author(s):  
Anjali Krishnan ◽  
Xiaozhen Mou
Keyword(s):  
Health Hazard ◽  
Aquatic Organisms ◽  
Water Soluble ◽  
Cyanobacterial Blooms ◽  
Aquatic Environments ◽  
Natural Environments ◽  
Exposure Pathway ◽  
Environmental Transformation ◽  
Cyclic Heptapeptide ◽  
Harmful Cyanobacterial Blooms

Harmful cyanobacterial blooms pose an environmental health hazard due to the release of water-soluble cyanotoxins. One of the most prevalent cyanotoxins in nature is microcystins (MCs), a class of cyclic heptapeptide hepatotoxins, and they are produced by several common cyanobacteria in aquatic environments. Once released from cyanobacterial cells, MCs are subjected to physical chemical and biological transformations in natural environments. MCs can also be taken up and accumulated in aquatic organisms and their grazers/predators and induce toxic effects in several organisms, including humans. This brief review aimed to summarize our current understanding on the chemical structure, exposure pathway, cytotoxicity, biosynthesis, and environmental transformation of microcystins.

RESEARCH OF THE MICROBIOM OF THE GASTROINTESTINAL TRACT OF THE ABERDIN-ANGUS BREED CATTLE

2021 ◽  
Author(s):  
А.Т. ДАУГАЛИЕВА ◽  
С.Т. ДАУГАЛИЕВА ◽  
Б.С. АРЫНГАЗИЕВ ◽  
Т.А. ЛАВРЕНТЬЕВА
Keyword(s):  
Genetic Identification ◽  
Intestinal Microbiome ◽  
Taxonomic Structure ◽  
Sequencing Technology ◽  
Microbial Composition ◽  
Angus Cattle ◽  
Taxonomic Profile ◽  
New Generation Sequencing ◽  
New Generation ◽  
Generation Sequencing

Целью исследования было определение таксономической структуры микробиома кишечника крупного рогатого скота породы Абердин-Ангус с помощью технологии секвенирования нового поколения. 16S метагеномный анализ, позволил определить микробный состав содержимого кишечника, минуя стадию культивирования на питательных средах. Проведена генетическая идентификация и получен таксономический профиль всех присутствующих бактерий, в том числе и некультивируемых форм. The aim of the study was to determine the taxonomic structure of the intestinal microbiome of Aberdeen Angus cattle using a new generation sequencing technology. 16S metagenomic analysis made it possible to determine the microbial composition of the intestinal contents bypassing the stage of cultivation on nutrient media. Genetic identification was carried out and a taxonomic profile of all bacteria present, including non-cultivated forms, was obtained. Key words: microbiome, cattle, Aberdeen Angus, next generation sequencing.

scholarly journals Earth observation for monitoring and mapping of cyanobacteria blooms. Case studies on five Italian lakes

2016 ◽  
Vol 76 (s1) ◽  
Author(s):  
Mariano Bresciani ◽  
Claudia Giardino ◽  
Rosaria Lauceri ◽  
Erica Matta ◽  
Ilaria Cazzaniga ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Algal Blooms ◽  
Remote Sensing Data ◽  
Late Summer ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
Landsat 8 ◽  
Negative Effects ◽  
Eutrophic Lakes ◽  
Chl A

Cyanobacterial blooms occur in many parts of the world as a result of entirely natural causes or human activity. Due to their negative effects on water resources, efforts are made to monitor cyanobacteria dynamics. This study discusses the contribution of remote sensing methods for mapping cyanobacterial blooms in lakes in northern Italy. Semi-empirical approaches were used to flag scum and cyanobacteria and spectral inversion of bio-optical models was adopted to retrieve chlorophyll-a (Chl-a) concentrations. Landsat-8 OLI data provided us both the spatial distribution of Chl-a concentrations in a small eutrophic lake and the patchy distribution of scum in Lake Como. ENVISAT MERIS time series collected from 2003 to 2011 enabled the identification of dates when cyanobacterial blooms affected water quality in three small meso-eutrophic lakes in the same region. On average, algal blooms occurred in the three lakes for about 5 days a year, typically in late summer and early autumn. A suite of hyperspectral sensors on air- and space-borne platforms was used to map Chl-a concentrations in the productive waters of the Mantua lakes, finding values in the range of 20 to 100 mgm-3. The present findings were obtained by applying state of the art of methods applied to remote sensing data. Further research will focus on improving the accuracy of cyanobacteria mapping and adapting the algorithms to the new-generation of satellite sensors.

scholarly journals Effects of Cyanobacteria on Phosphorus Cycling and Other Aquatic Organisms in Simulated Eutrophic Ecosystems

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2265
Author(s):  
Peng Gu ◽  
Qi Li ◽  
Hao Zhang ◽  
Xin Luo ◽  
Weizhen Zhang ◽  
...  
Keyword(s):  
Nutrient Management ◽  
Lake Taihu ◽  
Cyanobacterial Bloom ◽  
Aquatic Organisms ◽  
Pilot Scale ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Eutrophic Lakes ◽  
P Concentration ◽  
Bloom Formation

Cyanobacterial blooms caused by eutrophication in Lake Taihu have led to ecological threats to freshwater ecosystems. A pilot scale experiment was implemented to investigate the relationship between cyanobacteria and other aquatic plants and animals in simulated eutrophic ecosystems under different phosphorus (P) regimes. The results of this study showed that cyanobacteria had two characteristics favorable for bloom formation in eutrophic ecosystems. One is the nutrient absorption. The presence of alkaline phosphatase was beneficial for algal cells in nutrition absorption under low P concentration. Cyanobacteria exhibited a stronger ability to absorb and store P compared to Vallisneria natans, which contributed to the fast growth of algal cells between 0.2 and 0.5 mg·L−1 of P (p < 0.05). However, P loads affected only the maximum biomass, but not the growth phases. The growth cycle of cyanobacteria remained unchanged and was not related to P concentration. P cycling indicated that 43.05–69.90% of the total P existed in the form of sediment, and P content of cyanobacteria showed the highest increase among the organisms. The other is the release of microcystin. Toxic microcystin-LR was released into the water, causing indirectly the growth inhibition of Carassius auratus and Bellamya quadrata and the reduction of microbial diversity. These findings are of importance in exploring the mechanism of cyanobacterial bloom formation and the nutrient management of eutrophic lakes.

scholarly journals Biliary Microbiota and Bile Acid Composition in Cholelithiasis

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Vyacheslav A. Petrov ◽  
María A. Fernández-Peralbo ◽  
Rico Derks ◽  
Elena M. Knyazeva ◽  
Nikolay V. Merzlikin ◽  
...  
Keyword(s):  
Bile Acid ◽  
Acid Composition ◽  
Acid Concentration ◽  
Gallstone Disease ◽  
Alpha Diversity ◽  
Taurocholic Acid ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Opisthorchis Felineus ◽  
Taxonomic Profile

Background. A functional interplay between BAs and microbial composition in gut is a well-documented phenomenon. In bile, this phenomenon is far less studied, and with this report, we describe the interactions between the BAs and microbiota in this complex biological matrix. Methodology. Thirty-seven gallstone disease patients of which twenty-one with Opisthorchis felineus infection were enrolled in the study. The bile samples were obtained during laparoscopic cholecystectomy for gallstone disease operative treatment. Common bile acid composition was measured by LC-MS/MS. Gallbladder microbiota were previously analyzed with 16S rRNA gene sequencing on Illumina MiSeq platform. The associations between bile acid composition and microbiota were analyzed. Results. Bile acid signature and Opisthorchis felineus infection status exert influence on beta-diversity of bile microbial community. Direct correlations were found between taurocholic acid, taurochenodeoxycholic acid concentrations, and alpha-diversity of bile microbiota. Taurocholic acid and taurochenodeoxycholic acid both show positive associations with the presence of Chitinophagaceae family, Microbacterium and Lutibacterium genera, and Prevotella intermedia. Also, direct associations were identified for taurocholic acid concentration and the presence of Actinomycetales and Bacteroidales orders, Lautropia genus, Jeotgalicoccus psychrophilus, and Haemophilus parainfluenzae as well as for taurochenodeoxycholic acid and Acetobacteraceae family and Sphingomonas genus. There were no differences in bile acid concentrations between O. felineus-infected and noninfected patients. Conclusions/Significance. Associations between diversity, taxonomic profile of bile microbiota, and bile acid levels were evidenced in patients with cholelithiasis. Increase of taurochenodeoxycholic acid and taurocholic acid concentration correlates with bile microbiota alpha-diversity and appearance of opportunistic pathogens.

scholarly journals Inhibition of Extracellular Enzymes Exposed to Cyanopeptides

2020 ◽  
Vol 74 (3) ◽  
pp. 122-128
Author(s):  
Christine M. Egli ◽  
Regiane S. Natumi ◽  
Martin R. Jones ◽  
Elisabeth M.-L. Janssen
Keyword(s):  
Extracellular Enzymes ◽  
Heterotrophic Bacteria ◽  
Hydrolytic Enzymes ◽  
Aquatic Organisms ◽  
Freshwater Ecosystems ◽  
Cyanobacterial Blooms ◽  
Biologically Relevant ◽  
Metabolic Functions ◽  
Harmful Cyanobacterial Blooms ◽  
Quality Assessments

Harmful cyanobacterial blooms in freshwater ecosystems produce bioactive secondary metabolites including cyanopeptides that pose ecological and human health risks. Only adverse effects of one class of cyanopeptides, microcystins, have been studied extensively and have consequently been included in water quality assessments. Inhibition is a commonly observed effect for enzymes exposed to cyanopeptides and has mostly been investigated for human biologically relevant model enzymes. Here, we investigated the inhibition of ubiquitous aquatic enzymes by cyanobacterial metabolites. Hydrolytic enzymes are utilized in the metabolism of aquatic organisms and extracellularly by heterotrophic bacteria to obtain assimilable substrates. The ubiquitous occurrence of hydrolytic enzymes leads to the co-occurrence with cyanopeptides especially during cyanobacterial blooms. Bacterial leucine aminopeptidase and alkaline phosphatase were exposed to cyanopeptide extracts of different cyanobacterial strains ( Microcystis aeruginosa wild type and microcystin-free mutant, Planktothrix rubescens) and purified cyanopeptides. We observed inhibition of aminopeptidase and phosphatase upon exposure, especially to the apolar fractions of the cyanobacterial extracts. Exposure to the dominant cyanopeptides in these extracts confirmed that purified microcystins, aerucyclamide A and cyanopeptolin A inhibit the aminopeptidase in the low mg L–1 range while the phosphatase was less affected. Inhibition of aquatic enzymes can reduce the turnover of nutrients and carbon substrates and may also impair metabolic functions of grazing organisms.

scholarly journals Comparison of Soil Microbial Composition and Diversity Between Mixed and Monoculture Rubber Plantations in Hainan Province, China

2019 ◽  
Vol 12 ◽  
pp. 194008291987607 ◽  
Author(s):  
Muhammad Tahir Jatoi ◽  
Guoyu Lan ◽  
Zhixiang Wu ◽  
Rui Sun ◽  
Chuan Yang ◽  
...  
Keyword(s):  
Soil Ph ◽  
Hevea Brasiliensis ◽  
Fungal Communities ◽  
Rubber Plantation ◽  
Sequencing Analysis ◽  
Microbial Composition ◽  
Bacterial Composition ◽  
Rubber Plantations ◽  
Significant Difference ◽  
Soil Bacterial

This study aimed to compare monoculture and mixed rubber plantations in terms of their soil bacterial and fungal composition. An Illumina MiSeq sequencing analysis was performed to investigate the composition and diversity of the soil bacterial and fungal communities among three different rubber ( Hevea brasiliensis) plantations: monoculture, Mixed 1 ( Hevea brasiliensis and Mytilaria laosensis), and Mixed 2 ( Hevea brasiliensis and Michelia macclurei) in Hainan. The results showed that the bacterial composition of the three rubber plantations was basically similar. However, there was a significant difference in fungal communities among the three rubber plantations at both the phylum and operational taxonomic unit level. The species richness, Chao, and Shannon diversity of bacterial communities of monoculture rubber plantations were higher than the Mixed 1 and Mixed 2 rubber plantations, whereas all diversity indexes of fungal communities were relatively equal for the monoculture and mixed rubber plantations. Soil nutrition (such as total nitrogen and total potassium) and soil pH are the main drivers of the bacterial composition ( p <  .001). However, soil pH and water content are the main drivers of the fungal composition ( p <  .001), and to some extent, soil pH can increase soil bacteria diversity. We suggest that alkaline fertilizers should be applied in mixed rubber plantations to improve the soil pH and, consequently, to increase the total diversity of the rubber plantation.

scholarly journals High-Throughput, Sequence-Based Analysis of the Microbiota of Greek Kefir Grains from Two Geographic Regions

2020 ◽  
Vol 58 (2) ◽  
pp. 138-146
Author(s):  
Mary S. Kalamaki ◽  
Apostolos S. Angelidis
Keyword(s):  
Bacterial Community ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Geographic Origin ◽  
Probiotic Properties ◽  
Sequencing Analysis ◽  
Microbial Composition ◽  
Bacterial Phyla ◽  
Geographic Regions ◽  
Kefir Grains

Research background. Kefir is a natural probiotic drink traditionally produced by milk fermentation using kefir grains. Kefir grains are composed of a complex population of bacteria and yeasts embedded in a polysaccharide-protein matrix. The geographic origin of kefir grains may largely influence their microbial composition and the associated kefir drink properties. Although the detailed bacterial composition of kefir grains from several geographic regions has been reported, to date, analogous data about the microbiome of Greek kefir are lacking. Hence, the aim of this study is to investigate the structure and the diversity of the bacterial community of Greek kefir grains.Experimental approach. The bacterial community structure and diversity of two different kefir grains from distant geographic regions in Greece were examined via high-throughput sequencing analysis, a culture-independent metagenomic approach, targeting the 16S rRNA V4 variable region, in order to gain a deeper understanding of their bacterial population diversities.Results and conclusions. Firmicutes (a phylum that includes lactic acid bacteria) was strikingly dominant amongst the identified bacterial phyla, with over 99 % of the sequences from both kefir grains classified to this phylum. At the family level, Lactobacillaceae sequences accounted for more than 98 % of the operational taxonomic units (OTUs), followed by Ruminococcaceae, Lahnospiraceae, Bacteroidaceae and other bacterial families of lesser abundance. Α relatively small number of bacterial genera dominated, with Lactobacillus kefiranofaciens being the most abundant in both kefir grains (95.0 % of OTUs in kefir A and 96.3 % of OTUs in kefir B). However, a quite variable subdominant population was also present in both grains, including bacterial genera that have been previously associated with the gastrointestinal tract of humans and animals, some of which are believed to possess probiotic properties (Faecalibacterium spp., Bacteroides spp., Blautia spp.). Differences among the bacterial profiles of the two grains were very small indicating a high homogeneity despite the distant geographic origin.Novelty and scientific contribution. This is the first study to deeply explore and report on the bacterial diversity and species richness of Greek kefir.

scholarly journals Rapid adaptation of harmful cyanobacteria to rising CO2

2016 ◽  
Vol 113 (33) ◽  
pp. 9315-9320 ◽  
Author(s):  
Giovanni Sandrini ◽  
Xing Ji ◽  
Jolanda M. H. Verspagen ◽  
Robert P. Tann ◽  
Pieter C. Slot ◽  
...  
Keyword(s):  
Cyanobacterial Bloom ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
High Flux ◽  
Flux Rate ◽  
Eutrophic Lakes ◽  
Field Evidence ◽  
Evolutionary Changes ◽  
Lakes And Reservoirs ◽  
Harmful Cyanobacterial Blooms

Rising atmospheric CO2 concentrations are likely to affect many ecosystems worldwide. However, to what extent elevated CO2 will induce evolutionary changes in photosynthetic organisms is still a major open question. Here, we show rapid microevolutionary adaptation of a harmful cyanobacterium to changes in inorganic carbon (Ci) availability. We studied the cyanobacterium Microcystis, a notorious genus that can develop toxic cyanobacterial blooms in many eutrophic lakes and reservoirs worldwide. Microcystis displays genetic variation in the Ci uptake systems BicA and SbtA, where BicA has a low affinity for bicarbonate but high flux rate, and SbtA has a high affinity but low flux rate. Our laboratory competition experiments show that bicA + sbtA genotypes were favored by natural selection at low CO2 levels, but were partially replaced by the bicA genotype at elevated CO2. Similarly, in a eutrophic lake, bicA + sbtA strains were dominant when Ci concentrations were depleted during a dense cyanobacterial bloom, but were replaced by strains with only the high-flux bicA gene when Ci concentrations increased later in the season. Hence, our results provide both laboratory and field evidence that increasing carbon concentrations induce rapid adaptive changes in the genotype composition of harmful cyanobacterial blooms.

Influence of extended water column mixing during the first 2 years of hypolimnetic oxygenation on the phytoplankton community of Amisk Lake, Alberta

1997 ◽  
Vol 54 (9) ◽  
pp. 2133-2145 ◽  
Author(s):  
D J Webb ◽  
R D Robarts ◽  
E E Prepas
Keyword(s):  
Water Column ◽  
Trophic Status ◽  
Phytoplankton Community ◽  
Euphotic Zone ◽  
Open Water ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
Chl A ◽  
Hypolimnetic Oxygenation ◽  
Physical Variables

The phytoplankton community, physical variables, and nutrient and chlorophyll a (Chl a) concentrations were monitored during the first two of six open-water seasons of hypolimnetic oxygenation in double-basined Amisk Lake, Alberta. Deep mixing of the water column in the treated basin (Zmax = 34 m) in spring was enhanced by hypolimnetic oxygenation. Oxygenation began in June 1988, when stratification was likely already established, but subsequent year-round treatment favoured an extended spring diatom bloom (Asterionella formosa and Cyclotella spp.), followed by a delay in the development of, and reduction in the severity of, cyanobacterial blooms (Aphanizomenon flos-aquae and Anabaena flos-aquae) in 1989. Historically, mean summer Chl a and total phosphorus (TP) concentrations in the euphotic zone (0-6 m) of the treated basin were 15.9 ± 1.6 and 33.5 ± 1.5 µg ·L-1, respectively, indicating a eutrophic lake. In 1988 and 1989, mean summer Chl a (10.0 ± 0.6 and 8.1 ± 0.7 µg ·L-1, respectively) and TP concentrations (29.0 ± 0.5 and 22.5 ± 0.9 µg ·L-1, respectively) in this stratum were lower than historic values (P < 0.05), indicating that the trophic status of Amisk Lake had shifted towards mesotrophy.

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