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Park Y, Kim W, Cha Y, Kim M, Park W. Alleviation of H 2O 2 toxicity by extracellular catalases in the phycosphere of Microcystis aeruginosa. HARMFUL ALGAE 2024; 137:102680. [PMID: 39003030 DOI: 10.1016/j.hal.2024.102680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/20/2024] [Accepted: 06/16/2024] [Indexed: 07/15/2024]
Abstract
High levels of environmental H2O2 represent a threat to many freshwater bacterial species, including toxic-bloom-forming Microcystis aeruginosa, particularly under high-intensity light conditions. The highest extracellular catalase activity-possessing Pseudoduganella aquatica HC52 was chosen among 36 culturable symbiotic isolates from the phycosphere in freshly collected M. aeruginosa cells. A zymogram for catalase activity revealed the presence of only one extracellular catalase despite the four putative catalase genes (katA1, katA2, katE, and srpA) identified in the newly sequenced genome (∼6.8 Mb) of P. aquatica HC52. Analysis of secreted catalase using liquid chromatography-tandem mass spectrometry was identified as KatA1, which lacks a typical signal peptide, although the underlying mechanism for its secretion is unknown. The expression of secreted KatA1 appeared to be induced in the presence of H2O2. Proteomic analysis also confirmed the presence of KatA1 inside the outer membrane vesicles secreted by P. aquatica HC52 following exposure to H2O2. High light intensities (> 100 µmol m-2 s-1) are known to kill catalase-less axenic M. aeruginosa cells, but the present study found that the presence of P. aquatica cells supported the growth of M. aeruginosa, while the extracellular catalases in supernatant or purified form also sustained the growth of M. aeruginosa under the same conditions. Our results suggest that the extracellular catalase secreted by P. aquatica HC52 enhances the tolerance of M. aeruginosa to H2O2, thus promoting the formation of M. aeruginosa blooms under high light intensities.
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Affiliation(s)
- Yerim Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Yeji Cha
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Minkyung Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea.
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2
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Krausfeldt LE, Shmakova E, Lee HW, Mazzei V, Loftin KA, Smith RP, Karwacki E, Fortman PE, Rosen BH, Urakawa H, Dadlani M, Colwell RR, Lopez JV. Microbial diversity, genomics, and phage-host interactions of cyanobacterial harmful algal blooms. mSystems 2024; 9:e0070923. [PMID: 38856205 PMCID: PMC11265339 DOI: 10.1128/msystems.00709-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 11/13/2023] [Indexed: 06/11/2024] Open
Abstract
The occurrence of cyanobacterial harmful algal blooms (cyanoHABs) is related to their physical and chemical environment. However, less is known about their associated microbial interactions and processes. In this study, cyanoHABs were analyzed as a microbial ecosystem, using 1 year of 16S rRNA sequencing and 70 metagenomes collected during the bloom season from Lake Okeechobee (Florida, USA). Biogeographical patterns observed in microbial community composition and function reflected ecological zones distinct in their physical and chemical parameters that resulted in bloom "hotspots" near major lake inflows. Changes in relative abundances of taxa within multiple phyla followed increasing bloom severity. Functional pathways that correlated with increasing bloom severity encoded organic nitrogen and phosphorus utilization, storage of nutrients, exchange of genetic material, phage defense, and protection against oxidative stress, suggesting that microbial interactions may promote cyanoHAB resilience. Cyanobacterial communities were highly diverse, with picocyanobacteria ubiquitous and oftentimes most abundant, especially in the absence of blooms. The identification of novel bloom-forming cyanobacteria and genomic comparisons indicated a functionally diverse cyanobacterial community with differences in its capability to store nitrogen using cyanophycin and to defend against phage using CRISPR and restriction-modification systems. Considering blooms in the context of a microbial ecosystem and their interactions in nature, physiologies and interactions supporting the proliferation and stability of cyanoHABs are proposed, including a role for phage infection of picocyanobacteria. This study displayed the power of "-omics" to reveal important biological processes that could support the effective management and prediction of cyanoHABs. IMPORTANCE Cyanobacterial harmful algal blooms pose a significant threat to aquatic ecosystems and human health. Although physical and chemical conditions in aquatic systems that facilitate bloom development are well studied, there are fundamental gaps in the biological understanding of the microbial ecosystem that makes a cyanobacterial bloom. High-throughput sequencing was used to determine the drivers of cyanobacteria blooms in nature. Multiple functions and interactions important to consider in cyanobacterial bloom ecology were identified. The microbial biodiversity of blooms revealed microbial functions, genomic characteristics, and interactions between cyanobacterial populations that could be involved in bloom stability and more coherently define cyanobacteria blooms. Our results highlight the importance of considering cyanobacterial blooms as a microbial ecosystem to predict, prevent, and mitigate them.
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Affiliation(s)
- Lauren E. Krausfeldt
- Department of Biological Sciences, Guy Harvey Oceanographic Center, Nova Southeastern University, Dania Beach, Florida, USA
| | - Elizaveta Shmakova
- Department of Biological Sciences, Guy Harvey Oceanographic Center, Nova Southeastern University, Dania Beach, Florida, USA
| | - Hyo Won Lee
- Department of Biological Sciences, Guy Harvey Oceanographic Center, Nova Southeastern University, Dania Beach, Florida, USA
| | - Viviana Mazzei
- U.S. Geological Survey, Caribbean–Florida Water Science Center, Orlando, Florida, USA
| | - Keith A. Loftin
- U.S. Geological Survey, Kansas Water Science Center, Lawrence, Kansas, USA
| | - Robert P. Smith
- Department of Biological Sciences, Guy Harvey Oceanographic Center, Nova Southeastern University, Dania Beach, Florida, USA
- Cell Therapy Institute, Kiran Patel College of Allopathic Medicine, Nova Southeastern University, Fort Lauderdale, Florida, USA
| | - Emily Karwacki
- U.S. Geological Survey, Caribbean–Florida Water Science Center, Orlando, Florida, USA
| | - P. Eric Fortman
- Department of Biological Sciences, Guy Harvey Oceanographic Center, Nova Southeastern University, Dania Beach, Florida, USA
| | - Barry H. Rosen
- Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Hidetoshi Urakawa
- Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, Florida, USA
| | | | - Rita R. Colwell
- Institute for Advanced Computer Studies, University of Maryland College Park, College Park, Maryland, USA
| | - Jose V. Lopez
- Department of Biological Sciences, Guy Harvey Oceanographic Center, Nova Southeastern University, Dania Beach, Florida, USA
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Hancock TL, Dahedl EK, Kratz MA, Urakawa H. The synchronicity of bloom-forming cyanobacteria transcription patterns and hydrogen peroxide dynamics. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123812. [PMID: 38527584 DOI: 10.1016/j.envpol.2024.123812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 03/27/2024]
Abstract
Hydrogen peroxide is a reactive oxygen species (ROS) naturally occurring at low levels in aquatic environments and production varies widely across different ecosystems. Oxygenic photosynthesis generates hydrogen peroxide as a byproduct, of which some portion can be released to ambient water. However, few studies have examined hydrogen peroxide dynamics in relation to cyanobacterial harmful algal blooms (cHABs). A year-long investigation of algal succession and hydrogen peroxide dynamics was conducted at the Caloosahatchee River, Florida, USA. We aimed to identify potential biological mechanisms responsible for elevated hydrogen peroxide production during cHAB events through the exploration of the freshwater microbial metatranscriptome. Hydrogen peroxide concentrations were elevated from February to September of 2021 when cyanobacteria were active and abundant. We observed one Microcystis cHAB event in spring and one in winter. Both had distinct nutrient uptake and cyanotoxin gene expression patterns. While meaningful levels of microcystin were only detected during periods of elevated hydrogen peroxide, cyanopeptolin was by far the most expressed cyanotoxin during the spring bloom when hydrogen peroxide was at its yearly maxima. Gene expressions of five microbial enzymes (Rubisco, superoxide dismutase, cytochrome b559, pyruvate oxidase, and NADH dehydrogenase) positively correlated to hydrogen peroxide concentrations. Additionally, there was higher nitrogen-fixing gene (nifDKH) expression by filamentous cyanobacteria after the spring bloom but no secondary bloom formation occurred. Overall, elevated environmental hydrogen peroxide concentrations were linked to cyanobacterial dominance and greater expression of specific enzymes in the photosynthesis of cyanobacteria. This implicates cyanobacterial photosynthesis and growth results in increased hydrogen peroxide generation as reflected in measured environmental concentrations.
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Affiliation(s)
- Taylor L Hancock
- School of Geosciences, University of South Florida, Tampa, FL, 33620, USA; Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Elizabeth K Dahedl
- Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Michael A Kratz
- Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, Florida, USA
| | - Hidetoshi Urakawa
- School of Geosciences, University of South Florida, Tampa, FL, 33620, USA; Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, Florida, USA.
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4
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Lefler FW, Barbosa M, Berthold DE, Roten R, Bishop WM, Laughinghouse HD. Microbial Community Response to Granular Peroxide-Based Algaecide Treatment of a Cyanobacterial Harmful Algal Bloom in Lake Okeechobee, Florida (USA). Toxins (Basel) 2024; 16:206. [PMID: 38787058 PMCID: PMC11125911 DOI: 10.3390/toxins16050206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/19/2024] [Accepted: 04/20/2024] [Indexed: 05/25/2024] Open
Abstract
Cyanobacterial harmful algal blooms (cyanoHABs) occur in fresh water globally. These can degrade water quality and produce toxins, resulting in ecological and economic damages. Thus, short-term management methods (i.e., algaecides) are necessary to rapidly mitigate the negative impacts of cyanoHABs. In this study, we assess the efficacy of a hydrogen peroxide-based algaecide (PAK® 27) on a Microcystis dominated bloom which occurred within the Pahokee Marina on Lake Okeechobee, Florida, USA. We observed a significant reduction in chlorophyll a (96.81%), phycocyanin (93.17%), and Microcystis cell counts (99.92%), and a substantial reduction in microcystins (86.7%) 48 h after treatment (HAT). Additionally, there was a significant shift in bacterial community structure 48 HAT, which coincided with an increase in the relative abundance of photosynthetic protists. These results indicate that hydrogen peroxide-based algaecides are an effective treatment method for cyanoHAB control and highlight their effects on non-target microorganisms (i.e., bacteria and protists).
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Affiliation(s)
- Forrest W. Lefler
- Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL 33314, USA; (F.W.L.); (M.B.); (D.E.B.)
| | - Maximiliano Barbosa
- Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL 33314, USA; (F.W.L.); (M.B.); (D.E.B.)
| | - David E. Berthold
- Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL 33314, USA; (F.W.L.); (M.B.); (D.E.B.)
| | - Rory Roten
- SePRO Research and Technology Campus, 16013 Watson Seed Farm Road, Whitakers, NC 27891, USA; (R.R.); (W.M.B.)
| | - West M. Bishop
- SePRO Research and Technology Campus, 16013 Watson Seed Farm Road, Whitakers, NC 27891, USA; (R.R.); (W.M.B.)
| | - H. Dail Laughinghouse
- Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL 33314, USA; (F.W.L.); (M.B.); (D.E.B.)
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5
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Hancock TL, Dahedl EK, Kratz MA, Urakawa H. Bacterial community shifts induced by high concentration hydrogen peroxide treatment of Microcystis bloom in a mesocosm study. HARMFUL ALGAE 2024; 133:102587. [PMID: 38485437 DOI: 10.1016/j.hal.2024.102587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 12/18/2023] [Accepted: 01/30/2024] [Indexed: 03/19/2024]
Abstract
Hydrogen peroxide has gained popularity as an environmentally friendly treatment for cyanobacterial harmful algal blooms (cHABs) that takes advantage of oxidative stress sensitivity in cyanobacteria at controlled concentrations. Higher concentrations of hydrogen peroxide treatments may seem appealing for more severe cHABs but there is currently little understanding of the environmental impacts of this approach. Of specific concern is the associated microbial community, which may play key roles in the succession/recovery process post-treatment. To better understand impacts of a high concentration treatment on non-target microbial communities, we applied a hydrogen peroxide spray equating to a total volume concentration of 14 mM (473 mg/L, 0.04%) to 250 L mesocosms containing Microcystis bloom biomass, monitoring treatment and control mesocosms for 4 days. Cyanobacteria dominated control mesocosms throughout the experiment while treatment mesocosms experienced a 99% reduction, as determined by bacterial amplicon sequencing, and a 92% reduction in bacterial cell density within 1 day post-treatment. Only the bacterial community exhibited signs of regrowth, with a fold change of 9.2 bacterial cell density from day 1 to day 2. Recovery consisted of succession by Planctomycetota (47%) and Gammaproteobacteria (17%), which were likely resilient due to passive cell component compartmentalization and rapid upregulation of dnaK and groEL oxidative stress genes, respectively. The altered microbiome retained beneficial functionality of microcystin degradation through a currently recognized but unidentified pathway in Gammaproteobacteria, resulting in a 70% reduction coinciding with bacterial regrowth. There was also an 81% reduction of both total nitrogen and phosphorus, as compared to 91 and 93% in the control, respectively, due to high expressions of genes related to nitrogen (argH, carB, glts, glnA) and phosphorus (pntAB, phoB, pstSCB) cycling. Overall, we found a portion of the bacterial community was resilient to the high-concentration hydrogen peroxide treatment, resulting in Planctomycetota and Gammaproteobacteria dominance. This high-concentration treatment may be suitable to rapidly end cHABs which have already negatively impacted the aquatic environment rather than allow them to persist.
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Affiliation(s)
- Taylor L Hancock
- School of Geosciences, University of South Florida, Tampa, FL 33620, United States; Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, FL, United States
| | - Elizabeth K Dahedl
- Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, FL, United States
| | - Michael A Kratz
- Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, FL, United States
| | - Hidetoshi Urakawa
- School of Geosciences, University of South Florida, Tampa, FL 33620, United States; Department of Ecology and Environmental Studies, Florida Gulf Coast University, Fort Myers, FL, United States.
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6
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Baylous HR, Gladfelter MF, Gardner MI, Foley M, Wilson AE, Steffen MM. Indole-3-acetic acid promotes growth in bloom-forming Microcystis via an antioxidant response. HARMFUL ALGAE 2024; 133:102575. [PMID: 38485434 DOI: 10.1016/j.hal.2024.102575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/05/2024] [Accepted: 01/05/2024] [Indexed: 03/19/2024]
Abstract
Interactions between bacteria and phytoplankton in the phycosphere facilitate and constrain biogeochemical cycling in aquatic ecosystems. Indole-3-acetic acid (IAA) is a bacterially produced chemical signal that promotes growth of phytoplankton and plants. Here, we explored the impact of IAA on bloom-forming cyanobacteria and their associated bacteria. Exposure to IAA and its precursor, tryptophan, resulted in a strong growth response in a bloom of the freshwater cyanobacterium, Microcystis. Metatranscriptome analysis revealed the induction of an antioxidant response in Microcystis upon exposure to IAA, potentially allowing populations to increase photosynthetic rate and overcome internally generated reactive oxygen. Our data reveal that co-occurring bacteria within the phycosphere microbiome exhibit a division of labor for supportive functions, such as nutrient mineralization and transport, vitamin synthesis, and reactive oxygen neutralization. These complex dynamics within the Microcystis phycosphere microbiome are an example of interactions within a microenvironment that can have ecosystem-scale consequences.
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Affiliation(s)
- Hunter R Baylous
- Department of Biology, James Madison University, Harrisonburg, VA 22801, USA
| | - Matthew F Gladfelter
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Malia I Gardner
- Department of Biology, James Madison University, Harrisonburg, VA 22801, USA
| | - Madalynn Foley
- Department of Biology, James Madison University, Harrisonburg, VA 22801, USA
| | - Alan E Wilson
- School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Morgan M Steffen
- Department of Biology, James Madison University, Harrisonburg, VA 22801, USA.
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7
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Kim W, Park Y, Jung J, Jeon CO, Toyofuku M, Lee J, Park W. Biological and Chemical Approaches for Controlling Harmful Microcystis Blooms. J Microbiol 2024; 62:249-260. [PMID: 38587591 DOI: 10.1007/s12275-024-00115-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 04/09/2024]
Abstract
The proliferation of harmful cyanobacterial blooms dominated by Microcystis aeruginosa has become an increasingly serious problem in freshwater ecosystems due to climate change and eutrophication. Microcystis-blooms in freshwater generate compounds with unpleasant odors, reduce the levels of dissolved O2, and excrete microcystins into aquatic ecosystems, potentially harming various organisms, including humans. Various chemical and biological approaches have thus been developed to mitigate the impact of the blooms, though issues such as secondary pollution and high economic costs have not been adequately addressed. Red clays and H2O2 are conventional treatment methods that have been employed worldwide for the mitigation of the blooms, while novel approaches, such as the use of plant or microbial metabolites and antagonistic bacteria, have also recently been proposed. Many of these methods rely on the generation of reactive oxygen species, the inhibition of photosynthesis, and/or the disruption of cellular membranes as their mechanisms of action, which may also negatively impact other freshwater microbiota. Nevertheless, the underlying molecular mechanisms of anticyanobacterial chemicals and antagonistic bacteria remain unclear. This review thus discusses both conventional and innovative approaches for the management of M. aeruginosa in freshwater bodies.
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Affiliation(s)
- Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Yerim Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Jaejoon Jung
- Department of Life Science, Chung-Ang University, Seoul, 02841, Republic of Korea
| | - Che Ok Jeon
- Department of Life Science, Chung-Ang University, Seoul, 02841, Republic of Korea
| | - Masanori Toyofuku
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-0006, Japan
| | - Jiyoung Lee
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, 43210, USA
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, 43210, USA
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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8
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Baker D, Godwin CM, Khanam M, Burtner AM, Dick GJ, Denef VJ. Variation in resource competition traits among Microcystis strains is affected by their microbiomes. MLIFE 2023; 2:401-415. [PMID: 38818269 PMCID: PMC10989160 DOI: 10.1002/mlf2.12094] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 10/11/2023] [Accepted: 10/13/2023] [Indexed: 06/01/2024]
Abstract
Freshwater harmful algal blooms are often dominated by Microcystis, a phylogenetically cohesive group of cyanobacteria marked by extensive genetic and physiological diversity. We have previously shown that this genetic diversity and the presence of a microbiome of heterotrophic bacteria influences competitive interactions with eukaryotic phytoplankton. In this study, we sought to explain these observations by characterizing Monod equation parameters for resource usage (maximum growth rate μ max, half-saturation value for growth K s, and quota) as a function of N and P levels for four strains (NIES-843, PCC 9701, PCC 7806 [WT], and PCC 7806 ΔmcyB) in presence and absence of a microbiome derived from Microcystis isolated from Lake Erie. Results indicated limited differences in maximum growth rates but more pronounced differences in half-saturation values among Microcystis strains. The largest impact of the microbiome was reducing the minimal nitrogen concentration sustaining growth and reducing half saturation values, with variable results depending on the Microcystis strain. Microcystis strains also differed from each other in their N and P quotas and the extent to which microbiome presence affected them. Our data highlight the importance of the microbiome in altering Microcystis-intrinsic traits, strain competitive hierarchies, and thus bloom dynamics. As quota, μ max, and K s are commonly used in models for harmful algal blooms, our data suggest that model improvement may be possible by incorporating genotype dependencies of resource-use parameters.
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Affiliation(s)
- Dylan Baker
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichiganUSA
| | - Casey M. Godwin
- Cooperative Institute for Great Lakes Research, School for Environment and SustainabilityUniversity of MichiganAnn ArborMichiganUSA
| | - Muhtamim Khanam
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichiganUSA
| | - Ashley M. Burtner
- Cooperative Institute for Great Lakes Research, School for Environment and SustainabilityUniversity of MichiganAnn ArborMichiganUSA
| | - Gregory J. Dick
- Cooperative Institute for Great Lakes Research, School for Environment and SustainabilityUniversity of MichiganAnn ArborMichiganUSA
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMichiganUSA
| | - Vincent J. Denef
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichiganUSA
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Wang Y, Ning W, Li S, Gao C, Cui R, Guo W, Chang JS, Ho SH. Metabonomics analysis of microalga Scenedesmus obliquus under ciprofloxacin stress. ENVIRONMENTAL RESEARCH 2023; 237:116974. [PMID: 37625537 DOI: 10.1016/j.envres.2023.116974] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/05/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
The wide use of antibiotics in aquaculture has triggered global ecological security issue. Microalgal bioremediation is a promising strategy for antibiotics elimination due to carbon recovery, detoxification and various ecological advantages. However, a lack of understanding with respect to the corresponding regulation mechanism towards antibiotic stress may limit its practical applicability. The microalga Scenedesmus obliquus was shown to be capable of effectively eliminating ciprofloxacin (CIP), which is a common antibiotic used in aquaculture. However, the corresponding transcriptional alterations require further investigation and verification at the metabolomic level. Thus, this study uncovered the metabolomic profiles and detailed toxic and defense mechanisms towards CIP in S. obliquus using untargeted metabolomics. The enhanced oligosaccharide/polyol/lipid transport, up-regulation of carbohydrate and arachidonic acid metabolic pathways and increased energy production via EMP metabolism were observed as defense mechanisms of microalgal cells to xenobiotic CIP. The toxic metabolic responses included: (1) down-regulation of parts of mineral and organic transporters; (2) electrons competition between antibiotic and NAD during intracellular CIP degradation; and (3) suppressed expression of the hem gene in chlorophyll biosynthesis. This study describes the metabolic profile of microalgae during CIP elimination and reveals the key pathways from the perspective of metabolism, thereby providing information on the precise regulation of antibiotic bioremediation via microalgae.
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Affiliation(s)
- Yue Wang
- School of Environmental and Materials Engineering, Yantai University, Yantai, 264000, China
| | - Weihao Ning
- School of Environmental and Materials Engineering, Yantai University, Yantai, 264000, China
| | - Shengnan Li
- State Key Laboratory of Urban Water Resource and Environment School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Changfei Gao
- School of Environmental and Materials Engineering, Yantai University, Yantai, 264000, China
| | - Rong Cui
- School of Environmental and Materials Engineering, Yantai University, Yantai, 264000, China
| | - Wanqian Guo
- State Key Laboratory of Urban Water Resource and Environment School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, 701, Taiwan; Department of Mechanical Engineering, City University of Hong Kong, Kowloon Tang, Hong Kong, China; Department of Chemical and Materials Engineering, Tunghai University, Taichung, 407, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, 407, Taiwan
| | - Shih-Hsin Ho
- State Key Laboratory of Urban Water Resource and Environment School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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10
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Qin H, Sandrini G, Piel T, Slot PC, Huisman J, Visser PM. The harmful cyanobacterium Microcystis aeruginosa PCC7806 is more resistant to hydrogen peroxide at elevated CO 2. HARMFUL ALGAE 2023; 128:102482. [PMID: 37714576 DOI: 10.1016/j.hal.2023.102482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 07/28/2023] [Accepted: 07/28/2023] [Indexed: 09/17/2023]
Abstract
Rising atmospheric CO2 can intensify harmful cyanobacterial blooms in eutrophic lakes. Worldwide, these blooms are an increasing environmental concern. Low concentrations of hydrogen peroxide (H2O2) have been proposed as a short-term but eco-friendly approach to selectively mitigate cyanobacterial blooms. However, sensitivity of cyanobacteria to H2O2 can vary depending on the available resources. To find out how cyanobacteria respond to H2O2 under elevated CO2, Microcystis aeruginosa PCC 7806 was cultured in chemostats with nutrient-replete medium under C-limiting and C-replete conditions (150 ppm and 1500 ppm CO2, respectively). Microcystis chemostats exposed to high CO2 showed higher cell densities, biovolumes, and microcystin contents, but a lower photosynthetic efficiency and pH compared to the cultures grown under low CO2. Subsamples of the chemostats were treated with different concentrations of H2O2 (0-10 mg·L-1 H2O2) in batch cultures under two different light intensities (15 and 100 μmol photons m-2·s-1) and the response in photosynthetic vitality was monitored during 24 h. Results showed that Microcystis was more resistant to H2O2 at elevated CO2 than under carbon-limited conditions. Both low and high CO2-adapted cells were more sensitive to H2O2 at high light than at low light. Microcystins (MCs) leaked out of the cells of cultures exposed to 2-10 mg·L-1 H2O2, while the sum of intra- and extracellular MCs decreased. Although both H2O2 and CO2 concentrations in lakes vary in response to many factors, these results imply that it may become more difficult to suppress cyanobacterial blooms in eutrophic lakes when atmospheric CO2 concentrations continue to rise.
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Affiliation(s)
- Hongjie Qin
- Guangdong Provincial Key Lab of Ornamental Plant Germplasm Innovation and Utilization, Environmental Horticulture Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China; Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands; Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Giovanni Sandrini
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands; Department of Technology & Sources, Evides Water Company, Rotterdam, The Netherlands
| | - Tim Piel
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Pieter C Slot
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands
| | - Petra M Visser
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, PO Box 94240, 1090 GE Amsterdam, The Netherlands.
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11
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Lefler FW, Barbosa M, Zimba PV, Smyth AR, Berthold DE, Laughinghouse HD. Spatiotemporal diversity and community structure of cyanobacteria and associated bacteria in the large shallow subtropical Lake Okeechobee (Florida, United States). Front Microbiol 2023; 14:1219261. [PMID: 37711696 PMCID: PMC10499181 DOI: 10.3389/fmicb.2023.1219261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/14/2023] [Indexed: 09/16/2023] Open
Abstract
Lake Okeechobee is a large eutrophic, shallow, subtropical lake in south Florida, United States. Due to decades of nutrient loading and phosphorus rich sediments, the lake is eutrophic and frequently experiences cyanobacterial harmful algal blooms (cyanoHABs). In the past, surveys of the phytoplankton community structure in the lake have been conducted by morphological studies, whereas molecular based studies have been seldom employed. With increased frequency of cyanoHABs in Lake Okeechobee (e.g., 2016 and 2018 Microcystis-dominated blooms), it is imperative to determine the diversity of cyanobacterial taxa that exist within the lake and the limnological parameters that drive bloom-forming genera. A spatiotemporal study of the lake was conducted over the course of 1 year to characterize the (cyano)bacterial community structure, using 16S rRNA metabarcoding, with coincident collection of limnological parameters (e.g., nutrients, water temperature, major ions), and cyanotoxins. The objectives of this study were to elucidate spatiotemporal trends of community structure, identify drivers of community structure, and examine cyanobacteria-bacterial relationships within the lake. Results indicated that cyanobacterial communities within the lake were significantly different between the wet and dry season, but not between periods of nitrogen limitation and co-nutrient limitation. Throughout the year, the lake was primarily dominated by the picocyanobacterium Cyanobium. The bloom-forming genera Cuspidothrix, Dolichospermum, Microcystis, and Raphidiopsis were highly abundant throughout the lake and had disparate nutrient requirements and niches within the lake. Anatoxin-a, microcystins, and nodularins were detected throughout the lake across both seasons. There were no correlated (cyano)bacteria shared between the common bloom-forming cyanobacteria Dolichospermum, Microcystis, and Raphidiopsis. This study is the first of its kind to use molecular based methods to assess the cyanobacterial community structure within the lake. These data greatly improve our understanding of the cyanobacterial community structure within the lake and the physiochemical parameters which may drive the bloom-forming taxa within Lake Okeechobee.
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Affiliation(s)
- Forrest W. Lefler
- Agronomy Department, Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL, United States
| | - Maximiliano Barbosa
- Agronomy Department, Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL, United States
| | - Paul V. Zimba
- Rice Rivers Center, Virginia Commonwealth University, Charles City, VA, United States
| | - Ashley R. Smyth
- Soil, Water and Ecosystem Sciences Department, Tropical Research and Education Center, University of Florida—IFAS, Homestead, FL, United States
| | - David E. Berthold
- Agronomy Department, Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL, United States
| | - H. Dail Laughinghouse
- Agronomy Department, Fort Lauderdale Research and Education Center, University of Florida—IFAS, Davie, FL, United States
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12
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Huang T, Wang Y, Wang X, Ma L, Yang X. Discrepant diversity patterns and function of bacterial and fungal communities on an earthquake-prone mountain gradient in Northwest Sichuan, China. Front Microbiol 2023; 14:1217925. [PMID: 37675421 PMCID: PMC10477999 DOI: 10.3389/fmicb.2023.1217925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 08/07/2023] [Indexed: 09/08/2023] Open
Abstract
Patterns of microbial diversity on elevational gradients have been extensively studied, but little is known about those patterns during the restoration of earthquake-fractured alpine ecosystems. In this study, soil properties, soil enzyme activities, abundance and diversity of soil bacterial and fungal communities at four positions along a 2.6-km elevational gradient in the Snow Treasure Summit National Nature Reserve, located in Pingwu County, Southwest China. Although there were no significant changes in the soil chemical environment, bacterial and fungal communities were significantly different at different elevations. The overall fungal community presented an N-shaped diversity pattern with increasing elevation, while bacterial diversity decreased significantly with elevation. Changes in microbial diversity were associated with soil phosphorus, plant litter, and variations in dominant microbial taxa. Differences in enzyme activities among elevations were regulated by microbial communities, with changes in catalase and acid phosphatase activities mainly controlled by Acidobacteria and Planctomycetaceae bacteria, respectively (catalase: p < 0.001; acid phosphatase: p < 0.01), and those in β-glucosidase, sucrase, and urease activities mainly controlled by fungi. The β-glucosidase and sucrase were both positively correlated with Herpotrichiellaceae, and urease was positively correlated with Sebacinaceae (p < 0.05). These findings contribute to the conservation and management of mountain ecosystems in the face of changing environmental conditions. Further research can delve into the specific interactions between microbial communities, soil properties, and vegetation to gain deeper insights into the intricate ecological dynamics within earthquake-prone mountain ecosystems.
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Affiliation(s)
- Tianzhi Huang
- Key Laboratory of Ecological Safety and Protection of Sichuan Province, Mianyang Normal University, Mianyang, China
| | - Yingyan Wang
- College of Resources and Environmental Engineering, Mianyang Normal University, Mianyang, China
| | - Xuemei Wang
- College of Resources and Environmental Engineering, Mianyang Normal University, Mianyang, China
| | - Li Ma
- College of Resources and Environmental Engineering, Mianyang Normal University, Mianyang, China
| | - Xueting Yang
- Research Center of Sichuan County Economy Development, Mianyang Normal University, Mianyang, China
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13
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Yancey CE, Kiledal EA, Chaganti SR, Denef VJ, Errera RM, Evans JT, Hart LN, Isailovic D, James WS, Kharbush JJ, Kimbrel JA, Li W, Mayali X, Nitschky H, Polik CA, Powers MA, Premathilaka SH, Rappuhn NA, Reitz LA, Rivera SR, Zwiers CC, Dick GJ. The Western Lake Erie culture collection: A promising resource for evaluating the physiological and genetic diversity of Microcystis and its associated microbiome. HARMFUL ALGAE 2023; 126:102440. [PMID: 37290887 DOI: 10.1016/j.hal.2023.102440] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/24/2023] [Accepted: 04/28/2023] [Indexed: 06/10/2023]
Abstract
Cyanobacterial harmful algal blooms (cyanoHABs) dominated by Microcystis spp. have significant public health and economic implications in freshwater bodies around the world. These blooms are capable of producing a variety of cyanotoxins, including microcystins, that affect fishing and tourism industries, human and environmental health, and access to drinking water. In this study, we isolated and sequenced the genomes of 21 primarily unialgal Microcystis cultures collected from western Lake Erie between 2017 and 2019. While some cultures isolated in different years have a high degree of genetic similarity (genomic Average Nucleotide Identity >99%), genomic data show that these cultures also represent much of the breadth of known Microcystis diversity in natural populations. Only five isolates contained all the genes required for microcystin biosynthesis while two isolates contained a previously described partial mcy operon. Microcystin production within cultures was also assessed using Enzyme-Linked Immunosorbent Assay (ELISA) and supported genomic results with high concentrations (up to 900 μg L⁻¹) in cultures with complete mcy operons and no or low toxin detected otherwise. These xenic cultures also contained a substantial diversity of bacteria associated with Microcystis, which has become increasingly recognized as an essential component of cyanoHAB community dynamics. These results highlight the genomic diversity among Microcystis strains and associated bacteria in Lake Erie, and their potential impacts on bloom development, toxin production, and toxin degradation. This culture collection significantly increases the availability of environmentally relevant Microcystis strains from temperate North America.
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Affiliation(s)
- Colleen E Yancey
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - E Anders Kiledal
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Subba Rao Chaganti
- Cooperative Institute for Great Lakes Research (CIGLR), University of Michigan, 4840 S State Road, Ann Arbor, MI 48108, United States of America
| | - Vincent J Denef
- Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Reagan M Errera
- National Oceanic and Atmospheric Administration (NOAA), Great Lakes Environmental Research Laboratory (GLERL), 4840 S State Road, Ann Arbor, MI 48108, United States of America
| | - Jacob T Evans
- Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Lauren N Hart
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI 48109, United States of America; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Dragan Isailovic
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, United States of America
| | - William S James
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Jenan J Kharbush
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Jeffrey A Kimbrel
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States of America
| | - Wei Li
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States of America
| | - Xavier Mayali
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, United States of America
| | - Helena Nitschky
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Catherine A Polik
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - McKenzie A Powers
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Sanduni H Premathilaka
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, OH 43606, United States of America
| | - Nicole A Rappuhn
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Laura A Reitz
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Sara R Rivera
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Claire C Zwiers
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Gregory J Dick
- Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States of America; Cooperative Institute for Great Lakes Research (CIGLR), University of Michigan, 4840 S State Road, Ann Arbor, MI 48108, United States of America.
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14
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Yancey CE, Yu F, Tripathi A, Sherman DH, Dick GJ. Expression of Microcystis Biosynthetic Gene Clusters in Natural Populations Suggests Temporally Dynamic Synthesis of Novel and Known Secondary Metabolites in Western Lake Erie. Appl Environ Microbiol 2023; 89:e0209222. [PMID: 37070981 PMCID: PMC10231183 DOI: 10.1128/aem.02092-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/02/2023] [Indexed: 04/19/2023] Open
Abstract
Microcystis spp. produce diverse secondary metabolites within freshwater cyanobacterial harmful algal blooms (cyanoHABs) around the world. In addition to the biosynthetic gene clusters (BGCs) encoding known compounds, Microcystis genomes harbor numerous BGCs of unknown function, indicating a poorly understood chemical repertoire. While recent studies show that Microcystis produces several metabolites in the lab and field, little work has focused on analyzing the abundance and expression of its broader suite of BGCs during cyanoHAB events. Here, we use metagenomic and metatranscriptomic approaches to track the relative abundance of Microcystis BGCs and their transcripts throughout the 2014 western Lake Erie cyanoHAB. The results indicate the presence of several transcriptionally active BGCs that are predicted to synthesize both known and novel secondary metabolites. The abundance and expression of these BGCs shifted throughout the bloom, with transcript abundance levels correlating with temperature, nitrate, and phosphorus concentrations and the abundance of co-occurring predatory and competitive eukaryotic microorganisms, suggesting the importance of both abiotic and biotic controls in regulating expression. This work highlights the need for understanding the chemical ecology and potential risks to human and environmental health posed by secondary metabolites that are produced but often unmonitored. It also indicates the prospects for identifying pharmaceutical-like molecules from cyanoHAB-derived BGCs. IMPORTANCE Microcystis spp. dominate cyanobacterial harmful algal blooms (cyanoHABs) worldwide and pose significant threats to water quality through the production of secondary metabolites, many of which are toxic. While the toxicity and biochemistry of microcystins and several other compounds have been studied, the broader suite of secondary metabolites produced by Microcystis remains poorly understood, leaving gaps in our understanding of their impacts on human and ecosystem health. We used community DNA and RNA sequences to track the diversity of genes encoding synthesis of secondary metabolites in natural Microcystis populations and assess patterns of transcription in western Lake Erie cyanoHABs. Our results reveal the presence of both known gene clusters that encode toxic secondary metabolites as well as novel ones that may encode cryptic compounds. This research highlights the need for targeted studies of the secondary metabolite diversity in western Lake Erie, a vital freshwater source to the United States and Canada.
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Affiliation(s)
- Colleen E. Yancey
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Fengan Yu
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Ashootosh Tripathi
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Natural Products Discovery Core, University of Michigan, Ann Arbor, Michigan, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - David H. Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan, USA
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA
| | - Gregory J. Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
- Cooperative Institute for Great Lakes Research (CIGLR), University of Michigan, Ann Arbor, Michigan, USA
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15
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Hellweger FL, Schampera C, Martin RM, Eigemann F, Smith DJ, Dick GJ, Wilhelm SW. Response to Comment on “Models predict planned phosphorus load reduction will make Lake Erie more toxic”. Science 2022; 378:eade2277. [DOI: 10.1126/science.ade2277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Huisman
et al
. claim that our model is poorly supported or contradicted by other studies and the predictions are “seriously flawed.” We show their criticism is based on an incomplete selection of evidence, misinterpretation of data, or does not actually refute the model. Like all ecosystem models, our model has simplifications and uncertainties, but it is better than existing approaches hat ignore biology and do not predict toxin concentration.
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Affiliation(s)
- Ferdi L. Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | | | - Robbie M. Martin
- Department of Microbiology, University of Tennessee, Knoxville, TN
| | - Falk Eigemann
- Water Quality Engineering, Technical University of Berlin, Berlin, Germany
| | - Derek J. Smith
- Department of Earth and Environmental Science, University of Michigan, Ann Arbor, MA
| | - Gregory J. Dick
- Department of Earth and Environmental Science, University of Michigan, Ann Arbor, MA
- Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, MA
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16
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Weenink EFJ, Kraak MHS, van Teulingen C, Kuijt S, van Herk MJ, Sigon CAM, Piel T, Sandrini G, Leon-Grooters M, de Baat ML, Huisman J, Visser PM. Sensitivity of phytoplankton, zooplankton and macroinvertebrates to hydrogen peroxide treatments of cyanobacterial blooms. WATER RESEARCH 2022; 225:119169. [PMID: 36191528 DOI: 10.1016/j.watres.2022.119169] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/05/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Addition of hydrogen peroxide (H2O2) is a promising method to acutely suppress cyanobacterial blooms in lakes. However, a reliable H2O2 risk assessment to identify potential effects on non-target species is currently hampered by a lack of appropriate ecotoxicity data. The aim of the present study was therefore to quantify the responses of a wide diversity of freshwater phytoplankton, zooplankton and macroinvertebrates to H2O2 treatments of cyanobacterial blooms. To this end, we applied a multifaceted approach. First, we investigated the 24-h toxicity of H2O2 to three cyanobacteria (Planktothrix agardhii, Microcystis aeruginosa, Anabaena sp.) and 23 non-target species (six green algae, eight zooplankton and nine macroinvertebrate taxa), using EC50 values based on photosynthetic yield for phytoplankton and LC50 values based on mortality for the other organisms. The most sensitive species included all three cyanobacterial taxa, but also the rotifer Brachionus calyciflores and the cladocerans Ceriodaphnia dubia and Daphnia pulex. Next, the EC50 and LC50 values obtained from the laboratory toxicity tests were used to construct a species sensitivity distribution (SSD) for H2O2. Finally, the species predicted to be at risk by the SSD were compared with the responses of phytoplankton, zooplankton and macroinvertebrates to two whole-lake treatments with H2O2. The predictions of the laboratory-based SSD matched well with the responses of the different taxa to H2O2 in the lake. The first lake treatment, with a relatively low H2O2 concentration and short residence time, successfully suppressed cyanobacteria without major effects on non-target species. The second lake treatment had a higher H2O2 concentration with a longer residence time, which resulted in partial suppression of cyanobacteria, but also in a major collapse of rotifers and decreased abundance of small cladocerans. Our results thus revealed a trade-off between the successful suppression of cyanobacteria at the expense of adverse effects on part of the zooplankton community. This delicate balance strongly depends on the applied H2O2 dosage and may affect the decision whether to treat a lake or not.
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Affiliation(s)
- Erik F J Weenink
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Michiel H S Kraak
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Corné van Teulingen
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Senna Kuijt
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Maria J van Herk
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Corrien A M Sigon
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Tim Piel
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Giovanni Sandrini
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands; Department of Technology & Sources, Evides Water Company, Rotterdam, AL 3006, the Netherlands
| | - Mariël Leon-Grooters
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands; Department of Biomedical Engineering, Erasmus MC University Rotterdam, P.O. Box 2040, Rotterdam, CA 3000, the Netherlands
| | - Milo L de Baat
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands; KWR Water Research Institute, 3430 BB, Nieuwegein, the Netherlands
| | - Jef Huisman
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands
| | - Petra M Visser
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE Amsterdam, the Netherlands.
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17
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Uptake of Phytoplankton-Derived Carbon and Cobalamins by Novel Acidobacteria Genera in Microcystis Blooms Inferred from Metagenomic and Metatranscriptomic Evidence. Appl Environ Microbiol 2022; 88:e0180321. [PMID: 35862730 PMCID: PMC9317899 DOI: 10.1128/aem.01803-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Interactions between bacteria and phytoplankton can influence primary production, community composition, and algal bloom development. However, these interactions are poorly described for many consortia, particularly for freshwater bloom-forming cyanobacteria. Here, we assessed the gene content and expression of two uncultivated Acidobacteria from Lake Erie Microcystis blooms. These organisms were targeted because they were previously identified as important catalase producers in Microcystis blooms, suggesting that they protect Microcystis from H2O2. Metatranscriptomics revealed that both Acidobacteria transcribed genes for uptake of organic compounds that are known cyanobacterial products and exudates, including lactate, glycolate, amino acids, peptides, and cobalamins. Expressed genes for amino acid metabolism and peptide transport and degradation suggest that use of amino acids and peptides by Acidobacteria may regenerate nitrogen for cyanobacteria and other organisms. The Acidobacteria genomes lacked genes for biosynthesis of cobalamins but expressed genes for its transport and remodeling. This indicates that the Acidobacteria obtained cobalamins externally, potentially from Microcystis, which has a complete gene repertoire for pseudocobalamin biosynthesis; expressed them in field samples; and produced pseudocobalamin in axenic culture. Both Acidobacteria were detected in Microcystis blooms worldwide. Together, the data support the hypotheses that uncultured and previously unidentified Acidobacteria taxa exchange metabolites with phytoplankton during harmful cyanobacterial blooms and influence nitrogen available to phytoplankton. Thus, novel Acidobacteria may play a role in cyanobacterial physiology and bloom development. IMPORTANCE Interactions between heterotrophic bacteria and phytoplankton influence competition and successions between phytoplankton taxa, thereby influencing ecosystem-wide processes such as carbon cycling and algal bloom development. The cyanobacterium Microcystis forms harmful blooms in freshwaters worldwide and grows in buoyant colonies that harbor other bacteria in their phycospheres. Bacteria in the phycosphere and in the surrounding community likely influence Microcystis physiology and ecology and thus the development of freshwater harmful cyanobacterial blooms. However, the impacts and mechanisms of interaction between bacteria and Microcystis are not fully understood. This study explores the mechanisms of interaction between Microcystis and uncultured members of its phycosphere in situ with population genome resolution to investigate the cooccurrence of Microcystis and freshwater Acidobacteria in blooms worldwide.
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