Transcriptional profiles of Microcystis reveal gene expression shifts that promote bloom persistence in in situ mesocosms DOI Creative Commons
Lauren E. Krausfeldt, Paisley S. Samuel, Robert P. Smith

et al.

Microbiology Spectrum, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 18, 2024

ABSTRACT Harmful algal blooms caused by cyanobacteria threaten aquatic ecosystems, the economy, and human health. Previous work has tried to identify mechanisms that allow form, focusing on role of nutrients. However, little is known about how introduced nutrients influence gene expression in situ . To address this knowledge gap, we used mesocosms initiated with water experiencing a Microcystis bloom. We added pulses are commonly associated anthropogenic sources for 72 hours collected samples metatranscriptomics examine physiological function bloom status changed. The addition nitrogen (N) as urea, but not PO 4 , resulted conspicuous persistence at least 9 days after final introduction urea initially upregulation photosynthesis machinery, well phosphate, carbon, N transport metabolism. Once presumably became N-replete, amino acid metabolism, microcystin biosynthesis, other processes biomass generation occurred. These capacities coincided toxin-antitoxin systems, CRISPR- cas genes, transposases suggesting phage defense genome rearrangement critical persistence. Overall, our results show stepwise transcriptional response nutrients, specifically it sustained natural setting. transcriptomic shifts observed herein may serve markers longevity while providing insight into why over cyanobacteria. IMPORTANCE represent threat health ecosystems. Understanding persist help us develop warning indicators create novel mitigation strategies. Using mesocosm experiments an active bloom, measured transcription changes toxin-producing cyanobacterium important causing blooms. found (N), phosphorus, promoted longevity. initial genes involved import. At later times generation, protection, genomic rearrangement, toxin production was observed. Our suggest first fulfills nutritional requirements before investing energy pathways growth protection against competitors, which allowed more than week

Language: Английский

Nanofertilizers: Mechanisms, Efficacy, and Implications for Sustainable Agriculture DOI

Annish Shabiya,

Mansoor Ahmad Bhat, Prabhakar Singh

et al.

Published: Jan. 1, 2025

Language: Английский

Citations

1
Metagenomics reveals spatial variation in cyanobacterial composition, function, and biosynthetic potential in the Winam Gulf, Lake Victoria, Kenya DOI Creative Commons
Lauren Hart, Brittany N. Zepernick,

Kaela E. Natwora

et al.

Applied and Environmental Microbiology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

ABSTRACT The Winam Gulf in the Kenyan region of Lake Victoria experiences prolific, year-round cyanobacterial harmful algal blooms (cyanoHABs) which pose threats to human, livestock, and ecosystem health. To our knowledge, there is limited molecular research on gulf’s cyanoHABs, thus, strategies employed for survival proliferation by toxigenic cyanobacteria this remain largely unexplored. Here, we used metagenomics analyze Gulf’s composition, function, biosynthetic potential. Dolichospermum was dominant bloom-forming cyanobacterium, co-occurring with Microcystis at most sites. Planktothrix were more abundant shallow turbid Metagenome-assembled genomes (MAGs) harbored nitrogen fixation genes, suggesting diazotrophy as a potential mechanism supporting nitrogen-limited gulf. Over 300 gene clusters (BGCs) putatively encoding synthesis toxins other secondary metabolites identified across gulf, even sites where no visible cyanoHAB events. Almost all BGCs had known product, indicating diverse novel repertoire capable synthesizing or potentially therapeutic metabolites. MAGs contained mcy genes hepatotoxic microcystins are concern drinking water safety. These findings illustrate spatial variation their available dominate different ecological niches. This study underscores need further use genomic techniques elucidate dynamics mitigate effects cyanoHABs associated environmental, economic

Language: Английский

Citations

0
Temporal and spatial dynamics of harmful algal bloom-associated microbial communities in eutrophic Clear Lake, California DOI Creative Commons
Isha Kalra, Brittany Stewart,

Kyra M. Florea

et al.

Applied and Environmental Microbiology, Journal Year: 2025, Volume and Issue: unknown

Published: March 28, 2025

ABSTRACT Clear Lake is a large, natural eutrophic lake located in northern California, United States. Persistent, toxic cyanobacterial blooms have been reported the since 2011. However, our understanding of spatiotemporal distribution toxin-producing genera and their interaction with biotic abiotic environment limited. Moreover, few studies addressed how co-occurring microbial communities respond to these blooms. Using multi-domain 16S/18S rRNA gene amplicon sequencing, strong seasonal succession within eukaryotic assemblage was identified, which primarily explained by variation total phosphorus (~30%, P < 0.001) temperature (~15%, 0.01). Cyanobacterial often initiated proliferation diazotrophs ( Dolichospermum Nodularia ) concomitant increases nitrogen, followed non-diazotrophs, such as Microcystis, Limnothrix, Planktothrix . The picocyanobacterium Cyanobium , previously undocumented lake, dominant summer taxon western part Lake, accounting for ~45%–80% relative abundance reads. Seasonal influenced photosynthetic chlorophytes diatoms, well mixotrophic ciliates cryptophytes. Among all genera, Microcystis most strongly correlated microcystin concentrations 0.001), both appeared influence eukaryotes. Finally, using putative relationships based on correlation sequence environmental variables, several potential grazers were including cyclopoid copepods Cryptomonas These correlations need further confirmation experimental work validate nature relationships. IMPORTANCE an important habitat fish wildlife, also provides myriad human benefits, recreation, irrigation, drinking water. vital tribal tradition cultural practices. last decade, has experienced recurring harmful algal toxin levels that frequently exceed California voluntary guidance levels. high pose substantial threat residents, visitors, sustenance fishing beneficial uses. significant gaps remain bloom dynamics environments. This study characterized spatial patterns bloom-causing cyanobacteria identified major producer Lake. Additionally, bacterial characterized, interactions discussed.

Language: Английский

Citations

0
Photocatalysis and phosphorus drive organic production in algal-bacterial co-cultures treating oil sands process affected water DOI Creative Commons
Cassandra Chidiac, Timothy Michael Carter Leshuk, Frank Gu

et al.

Chemosphere, Journal Year: 2025, Volume and Issue: 377, P. 144322 - 144322

Published: April 4, 2025

Photocatalysis has been previously identified as an effective pre-treatment for biodegrading naphthenic acid fraction compounds (NAFCs) in oil sands process-affected water (OSPW), achieving mineralization rates unattainable by standalone methods. However, previous studies focused on bacteria cultures biological treatment, overlooking the potential of algae-bacteria co-growth and its possible effects enhancing mineralization. Thus, this study replicated those experiments under conditions that promote algal growth. Synthetic OSPW underwent photocatalytic varying durations, followed treatment illuminated microcosms. Biostimulation, through phosphate addition, was also tested to determine effect accelerating Photocatalytic pre-treatments 24 h or longer created oligotrophic conditions, triggering production algal-derived organics, which released nutrients into reduced during phase. Moreover, nutrient addition generally exacerbated these promoting photosynthetic biomass Nutrient-fixing symbiotic microbes were identified, contributing prolonged organic phases. These phases persistent generation could pose a risk eutrophication, highlighting need mitigate light exposure post-biological treatments. Under controlled exposure, BPCs with treatments offer scalable, energy-efficient solution addressing complex industrial wastewater challenges, advancing sustainable management similar hard-to-treat sources.

Language: Английский

Citations

0
Phytoplankton assemblage structure, drivers, and thresholds with a focus on harmful algal bloom ecology in the Lake Okeechobee system, Florida, USA. DOI Creative Commons
Viviana Mazzei, Kristy Lee Sullivan, Keith A. Loftin

et al.

Harmful Algae, Journal Year: 2024, Volume and Issue: 142, P. 102744 - 102744

Published: Nov. 9, 2024

Language: Английский

Citations

1
Transcriptional profiles of Microcystis reveal gene expression shifts that promote bloom persistence in in situ mesocosms DOI Creative Commons
Lauren E. Krausfeldt, Paisley S. Samuel, Robert P. Smith

et al.

Microbiology Spectrum, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 18, 2024

ABSTRACT Harmful algal blooms caused by cyanobacteria threaten aquatic ecosystems, the economy, and human health. Previous work has tried to identify mechanisms that allow form, focusing on role of nutrients. However, little is known about how introduced nutrients influence gene expression in situ . To address this knowledge gap, we used mesocosms initiated with water experiencing a Microcystis bloom. We added pulses are commonly associated anthropogenic sources for 72 hours collected samples metatranscriptomics examine physiological function bloom status changed. The addition nitrogen (N) as urea, but not PO 4 , resulted conspicuous persistence at least 9 days after final introduction urea initially upregulation photosynthesis machinery, well phosphate, carbon, N transport metabolism. Once presumably became N-replete, amino acid metabolism, microcystin biosynthesis, other processes biomass generation occurred. These capacities coincided toxin-antitoxin systems, CRISPR- cas genes, transposases suggesting phage defense genome rearrangement critical persistence. Overall, our results show stepwise transcriptional response nutrients, specifically it sustained natural setting. transcriptomic shifts observed herein may serve markers longevity while providing insight into why over cyanobacteria. IMPORTANCE represent threat health ecosystems. Understanding persist help us develop warning indicators create novel mitigation strategies. Using mesocosm experiments an active bloom, measured transcription changes toxin-producing cyanobacterium important causing blooms. found (N), phosphorus, promoted longevity. initial genes involved import. At later times generation, protection, genomic rearrangement, toxin production was observed. Our suggest first fulfills nutritional requirements before investing energy pathways growth protection against competitors, which allowed more than week

Language: Английский

Citations

0