Download or read book Sedimentary DNA based Reconstruction of Cyanobacterial Communities from Lake Tiefer See NE Germany for the Last 11 000 Years written by Ebuka Canisius Nwosu and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change and human-driven eutrophication promote the spread of harmful cyanobacteria blooms in lakes worldwide, which affects water quality and impairs the aquatic food chain. In recent times, sedimentary ancient DNA-based (sedaDNA) studies were used to probe how centuries of climate and environmental changes have affected cyanobacterial assemblages in temperate lakes. However, there is a lack of information on the consistency between sediment-deposited cyanobacteria communities versus those of the water column, and on the individual role of natural climatic changes versus human pressure on cyanobacteria community dynamics over multi-millennia time scales. Therefore, this thesis uses sedimentary ancient DNA of Lake Tiefer See in northeastern Germany to trace the deposition of cyanobacteria along the water column into the sediment, and to reconstruct cyanobacteria communities spanning the last 11,000 years using a set of molecular techniques including quantitative PCR, biomarkers, metabarcoding, and metagenome sequence analyses. ...

Download or read book Sedimentary DNA Reveals Centuries of Hidden Diversity in Lake Cyanobacterial Communities written by Marie-Eve Monchamp and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Using Sediment DNA Archives for Interpreting Long term Cyanobacterial Dynamics in the Anthropocene written by Hebah Shaker Mejbel and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change and eutrophication, accelerated by anthropogenic activities, have impacted aquatic ecosystems worldwide. These impacts have stimulated the expansion of cyanobacterial blooms which pose severe threats to ecosystem functioning, environmental health, and the economy. However, the long-term effects of environmental change on bloom-forming cyanobacteria are not well understood as traditional paleolimnological approaches are of limited use in the reconstruction of cyanobacterial dynamics through time. Here, sediment DNA (sedDNA) was used to investigate long-term cyanobacterial trends using sediments from two experimental (fertilized L227 and acidified L223) and two reference (L224 and L442) lakes in the Experimental Lakes Area, Canada. First, to determine whether taxonomic bias might arise from the cyanobacterial sediment record, I performed a 1-year incubation experiment comparing the degradation rates of selected cyanobacterial genes under contrasting environmental conditions. Based on first-order linear decay models, Synechococcus sp. (Synechococcales) decayed the slowest under cold, anoxic conditions, followed by Trichormus (Nostocales), then Microcystis (Chroococcales), suggesting differential preservation of DNA. I then compared the quantitative performance of droplet digital polymerase chain reaction (ddPCR) and high-throughput sequencing (HTS) for the analysis of sedDNA and found that the ddPCR results were more consistent with the known history of the lakes. Furthermore, ddPCR showed that cyanobacterial abundance increased over the past century in all study lakes, but the greatest increase was observed in experimentally fertilized L227. HTS revealed shifts in the cyanobacterial community towards Nostocales dominance and a decrease in alpha diversity in response to phosphorus-only additions. An increase in abundance of the mcyE gene (indicative of microcystin producing taxa) was uniquely observed in L227 when nitrogen additions ceased. Heating degree days were important in explaining variation in the cyanobacterial community composition in all lakes, but nutrients had a greater influence on the L227 community. When sediment data were compared to historical surface water phytoplankton records, moderate to strong correlations between the two archives were found, validating the use of sedDNA. This research demonstrated that sedDNA can elucidate cyanobacterial trends at the community, population, and species level over multidecadal timescales in response to environmental change.

Download or read book Assessment of Toxic Cyanobacterial Abundance at Hamilton Harbour from Analysis of Sediment and Water written by Miroslava Jonlija and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The western embayment of Lake Ontario, Hamilton Harbour, is one of the most polluted sites in the Laurentian Great Lakes and in recent years has seen a reoccurrence of cyanobacterial blooms. This study uses a multidisciplinary approach to examine the presences of toxic Cyanobacteria in the harbour in order to gain insight into these recurrent blooms. Microscopic analyses of phytoplankton samples collected during the 2009 summer-fall sampling season from two locations within the harbour showed the spatial and seasonal diversity of the contemporary cyanobacterial community. Microcystis colonies relative abundances in relation to total algal numbers were estimated. The lowest and highest relative abundances of Microcystis in the phytoplankton population were 0.6% and 9.7%, respectively, and showed seasonal variability between stations. Fourteen cyanobacterial genera comprising six families and three orders were identified and for which the most abundant filamentous genera during the summer-fall sampling season were Planktothrix, Aphanizomenon and Limnothrix. Potential microcystin producers Microcystis, Planktothrix, Aphanizomenon and Dolichospermum were also present and during the sampling period Microcystis was recorded at both stations on all dates, however, its relative abundance was below 10 % throughout the study period. The composition and abundance of filamentous cyanobacteria were observed to be positively statistically correlated to water quality environmental parameters dissolved nitrates (NO3/NO2), dissolved inorganic carbon (DIC), and conductivity. Redundancy analysis (RDA) found that 53.35% total variance of Aphanizomenon was correlated to low water column NO3/NO2 and conductivity, and higher water column DIC. 58.13% of the relative abundance of Planktothrix was correlated to high concentrations of dissolved nitrates, while 51.69% of total variance of Limnothrix was correlated to higher DIC and lower water column dissolved nitrate concentrations. Information about past cyanobacterial communities was obtained from the sediment core analysis, using paleolimnological and modern molecular methods. The age of the 100.5 cm long sediment core retrieved from the deepest part of Hamilton Harbour was established to be 140 years (1869-2009), using the Constant Rate of Supply (CRS) 210Pb age model. This age was not sufficient to provide information of harbour's environmental conditions, presence of the blooms, and triggers for their occurrence before European settlement in the area. Results of the HPLC analysis of fossil pigments indicated that the dominant members of the algal community have not changed over the 140 years and that cyanobacteria were regular members of the phytoplankton community. The composition of the major chlorophyll pigments indicated high presence of Chlorophyta and Bacillariophyta in the harbour at all times. The main algal groups identified on the basis of marker pigments presence, besides the Chlorophyta and Bacillariophyta, were the Dinophyta and the Cryptophyta. The presence of a scytonemin derivative, compound B, indicated that cyanobacterial blooms were occurring in past, before the first officially recorded blooms in the 1960s. Cyanobacterial pigments presence indicated that Cyanobacteria have been a regular but not dominant feature of Hamilton Harbour phytoplankton in the past. To our knowledge, this study is the first one examining fossil pigments from Hamilton Harbour. Results of the PCR-DGGE molecular analysis of 16S rRNA-V3 gene fragments from sedimentary DNA revealed the presence of thirteen cyanobacterial genotypes. The temporal change in the cyanobacterial community composition was indicated by the increasing number of species over time, from the oldest to the most recent sediment layers. The deepest sediment strata showed the lowest number (two bands) and intensity of bands. The most recent sediment layer had the greatest numbers (11) and intensity of bands. This increased diversity indicated changing environmental conditions in the harbour, primarily nutrient pollution and worsening water quality. Results of the PCR-DGGE molecular analysis of mcyE-AMT gene fragments showed that Microcystis aeruginosa and Planktothrix rubescens were two microcystin producers present in Hamilton Harbour over the last 80 years. The persistent presence and resilience of these two genera indicated a more serious and longer-term issue of toxic blooms than previously recognized. Historical records show that noticeable anthropogenic impact on Lake Ontario environment has been measurable since the 1780s, the first dramatic impact on the Lake Ontario watershed was evident from the mid1880s, the earliest evidence of eutrophication in the lake occurred between 1820 and 1850, while human induced environmental changes in Hamilton Harbour date back ca. 350 years. In the 1960s, cyanobacterial blooms were first officially recognized in the harbour and the lower Great Lakes. The present research is the first report of the mcyE module and AMT domain of microcystin genes being amplified from sediment of North American lakes, and showed that toxic Cyanobacterial have been regular members of Hamilton Harbour phytoplankton community for almost a century. This research considerably deepened the knowledge of the past toxic cyanobacterial blooms in Hamilton Harbour and their possible causes. It also showed that in the absence of historical records, both the PCR-DGGE method and the mcyE-AMT gene may be used for reconstruction of the past toxic blooms not only in the Laurentian Great Lakes, but also in other aquatic regions of the world impacted by toxic cyanobacterial blooms. Also, it demonstrated the utility of the combined molecular and paleolimnological analyses, which might become a useful tool in the determination of the bloom causes factors and in the mitigation of the future production of toxic blooms.

Download or read book Methods in Cyanobacterial Research written by Shailendra Pratap Singh and published by CRC Press. This book was released on 2024-06-14 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: This laboratory reference compiles the essential protocols used in cyanobacterial research. Cyanobacteria is a model system for biofuel production and sequestration of carbon dioxide to tackle global climate change due to increasing levels of greenhouse gases. Topics range from identification and growth parameters to biomolecule estimation and isolation. It also covers genome analysis and bioengineering of cyanobacteria for novel products. Key Features: Provides step-by-step procedures and troubleshooting tips Covers identification, growth parameters and pigment estimation methodologies Describes isolation, characterization and purification of microcystin, phycobiliproteins and scytonemin from cyanobacteria Discusses genomics, proteomics and bioengineering of cyanobacteria from novel products Explains sample preparation and visualization protocol for electron microscopy-based analysis of cyanobacteria This collection is useful to students and researchers in life sciences. It is also meant for industry experts who are involved in the production of biofuels, biofertilizers, other value-added products, and carbon sequestration using cyanobacteria.

Download or read book Temporal and Spatial Trends in Toxic Cyanobacteria as Identified Through Lake Sediment DNA written by Shinjini Pal and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Cyanobacterial Communities of Bavarian Lakes Based on the 16S RRNA Gene written by Franziska Romana Bauer and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Temporal Trends in Cyanobacteria Through Paleo Genetic Analyses written by William Dodsworth and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With increasing eutrophication and climate change, temperate lakes are experiencing conditions favoring cyanobacterial dominance, leading to toxic blooms. However, the relative importance of these two factors remains unclear, due to a lack of historical records. This thesis analyzed sediment DNA from four lakes in Central Ontario to quantify trends over the past ~ 200 years in bacteria, cyanobacteria, and microcystin toxins through ddPCR of target genes. Climate related variables explained a small amount of variation. However, lakes with more development exhibited significant increases in cyanobacterial dominance, indicating regime shifts not occurring in less developed lakes. These shifts were likely driven by nutrient loading in concert with climate change. Sediment cores were also compared within a single multi-basin lake to determine the effect of depth and morphometry on DNA preservation. Sites of greater depth (20 m +) were more conducive to long-term DNA preservation and sheltered morphometry increased sediment DNA deposition.

Download or read book Ancient DNA written by Beth Alison Shapiro and published by . This book was released on 2012-01-01 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ancient DNA presents an overview of the many of the protocols commonly used to study ancient DNA. These include laboratory instructions, extraction protocols, laboratory techniques, and suggestions for appropriate analytical approaches to make sense of the sequences obtained.

Download or read book Microorganisms in Home and Indoor Work Environments written by Brian Flannigan and published by CRC Press. This book was released on 2002-01-03 with total page 555 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the large amount of money spent on research into pollution of the indoor environment, the problem remains complex with major gaps in our knowledge of the identities and sources of pollutants and of the effects of prolonged exposure to indoor pollutants on health. Microorganisms in Home and Indoor Work Environments considers one such group o

Download or read book The Identification and Use of Palaearctic Chironomidae Larvae in Palaeoecology written by Stephen J. Brooks and published by . This book was released on 2007 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lake Go ci Central Poland written by Magdalena Ralska-Jasiewiczowa and published by . This book was released on 1998 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polen - Vegetationsgeschichte - Spätglazial.

Download or read book Evaluating Climate Change Impacts written by Vyacheslav Lyubchich and published by CRC Press. This book was released on 2020-10-06 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evaluating Climate Change Impacts discusses assessing and quantifying climate change and its impacts from a multi-faceted perspective of ecosystem, social, and infrastructure resilience, given through a lens of statistics and data science. It provides a multi-disciplinary view on the implications of climate variability and shows how the new data science paradigm can help us to mitigate climate-induced risk and to enhance climate adaptation strategies. This book consists of chapters solicited from leading topical experts and presents their perspectives on climate change effects in two general areas: natural ecosystems and socio-economic impacts. The chapters unveil topics of atmospheric circulation, climate modeling, and long-term prediction; approach the problems of increasing frequency of extreme events, sea level rise, and forest fires, as well as economic losses, analysis of climate impacts for insurance, agriculture, fisheries, and electric and transport infrastructures. The reader will be exposed to the current research using a variety of methods from physical modeling, statistics, and machine learning, including the global circulation models (GCM) and ocean models, statistical generalized additive models (GAM) and generalized linear models (GLM), state space and graphical models, causality networks, Bayesian ensembles, a variety of index methods and statistical tests, and machine learning methods. The reader will learn about data from various sources, including GCM and ocean model outputs, satellite observations, and data collected by different agencies and research units. Many of the chapters provide references to open source software R and Python code that are available for implementing the methods.

Download or read book Plankton Population Dynamics written by Louis Gressett Williams and published by . This book was released on 1962 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Annually Laminated Lake Sediments written by Wojciech Tylmann and published by MDPI. This book was released on 2020-04-28 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The collection of papers presented in this book illustrates the recent progress made in varved sediment research and highlights the large variety of methodological approaches and research directions applied. The contributions cover monitoring of modern sediment fluxes using sediment traps; geochronological and sedimentological analyses of annually laminated lacustrine sediments or varves; and multiproxy investigations, including geochemical and biological proxies as well as spatiotemporal analyses based on multicore studies supported by satellite images and X-ray computed tomography (CT). The scientific issues discuss the influences of hydrological and climatological phenomena on short-term changes in sediment flux, the relationships between biogeochemical (limnological) processes in the water column and the formation of varves, the preservation of environmental signals in varved sediments, and possibilities of synchronizing varved records with other high-resolution environmental archives such as tree rings.

Download or read book Physics and Chemistry of Ice written by Werner F. Kuhs and published by Royal Society of Chemistry. This book was released on 2007 with total page 721 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics and Chemistry of Ice is an authoritative summary of state-of the-art research contributions from the world's leading scientists. A key selection of submissions from to the 11th International Conference on the Physics and Chemistry of Ice, 2006 are presented here with a foreword by Werner F. Kuhs. An invaluable resource, this book provides researchers and professionals with up-to-date coverage on a wide range of areas in ice science including: " Spectroscopic and diffraction studies " Molecular dynamics simulations " Studies of ice mechanics " Quantum mechanical ab initio calculations " Ice and hydrate crystal growth and inhibition studies " Bulk and surface properties of ice and gas hydrates " Snow physics and chemistry This insight into topical aspects of ice research is a key point of reference for physicists, chemists, galciologists, cryo-biologists and professionals working in the fields of ice and hydrogen bonding. The Editor Werner F. Kuhs is a Professor of Crystallography at the University of G÷ttingen, Germany and has a career spanning 25 years of research in the field of water ices and gas hydrates using diffraction methods, neutron and Raman spectroscopy, scanning electron microscopy, atomic force and molecular dynamics simulations. He was the Chair of the 11th International Conference on the Physics and Chemistry of Ice.

Download or read book Reproductive Biology of Plants written by Kishan Gopal Ramawat and published by CRC Press. This book was released on 2016-04-19 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reproductive biology is the basis of species improvement and a thorough understanding of this is needed for plant improvement, whether by conventional or biotechnological methods. This book presents an up to date and comprehensive description of reproduction in lower plants, gymnosperms and higher plants. It covers general plant biology, pollinatio