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Piccini C, Martínez de la Escalera G, Segura AM, Croci C, Kruk C. The Microcystis-microbiome interactions: origins of the colonial lifestyle. FEMS Microbiol Ecol 2024; 100:fiae035. [PMID: 38499447 PMCID: PMC10996927 DOI: 10.1093/femsec/fiae035] [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: 01/04/2024] [Revised: 02/21/2024] [Accepted: 03/16/2024] [Indexed: 03/20/2024] Open
Abstract
Species of the Microcystis genus are the most common bloom-forming toxic cyanobacteria worldwide. They belong to a clade of unicellular cyanobacteria whose ability to reach high biomasses during blooms is linked to the formation of colonies. Colonial lifestyle provides several advantages under stressing conditions of light intensity, ultraviolet light, toxic substances and grazing. The progression from a single-celled organism to multicellularity in Microcystis has usually been interpreted as individual phenotypic responses of the cyanobacterial cells to the environment. Here, we synthesize current knowledge about Microcystis colonial lifestyle and its role in the organism ecology. We then briefly review the available information on Microcystis microbiome and propose that changes leading from single cells to colonies are the consequence of specific and tightly regulated signals between the cyanobacterium and its microbiome through a biofilm-like mechanism. The resulting colony is a multi-specific community of interdependent microorganisms.
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Affiliation(s)
- Claudia Piccini
- Departamento de Microbiología, Centro de Investigación en Ciencias Ambientales, Instituto de Investigaciones Biológicas Clemente Estable. Av. Italia 3318, Montevideo 11600, Uruguay
| | - Gabriela Martínez de la Escalera
- Departamento de Microbiología, Centro de Investigación en Ciencias Ambientales, Instituto de Investigaciones Biológicas Clemente Estable. Av. Italia 3318, Montevideo 11600, Uruguay
| | - Angel M Segura
- Modelización Estadística de Datos e Inteligencia Artificial, Centro Universitario Regional del Este, Universidad de la República. Ruta nacional Nº9 intersección con ruta Nº15, Uruguay
| | - Carolina Croci
- Departamento de Microbiología, Centro de Investigación en Ciencias Ambientales, Instituto de Investigaciones Biológicas Clemente Estable. Av. Italia 3318, Montevideo 11600, Uruguay
| | - Carla Kruk
- Modelización Estadística de Datos e Inteligencia Artificial, Centro Universitario Regional del Este, Universidad de la República. Ruta nacional Nº9 intersección con ruta Nº15, Uruguay
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales, Facultad de Ciencias, Universidad de la República. Iguá 4225, Montevideo 11400, Uruguay
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Wu K, Leliveld T, Zweers H, Rijnaarts H, Langenhoff A, Fernandes TV. Impact of mixed microalgal and bacterial species on organic micropollutants removal in photobioreactors under natural light. BIORESOURCE TECHNOLOGY 2024; 393:130083. [PMID: 38000642 DOI: 10.1016/j.biortech.2023.130083] [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: 09/29/2023] [Revised: 11/18/2023] [Accepted: 11/19/2023] [Indexed: 11/26/2023]
Abstract
Single microalgae species are effective at the removal of various organic micropollutants (OMPs), however increased species diversity might enhance this removal. Sixteen OMPs were added to 2 continuous photobioreactors, one inoculated with Chlorella sorokiniana and the other with a microalgal-bacterial community, for 112 d under natural light. Three media were sequentially used in 3 Periods: I) synthetic sewage (d 0-28), II) 10x diluted anaerobically digested black water (AnBW) (d 28-94) and III) 5x diluted AnBW (d 94-112). Twelve OMPs were removed > 30 %, while 4 were < 10 % removed. Removal efficiencies were similar for 9 OMPs, yet the mixed community showed a 2-3 times higher removal capacity (µg OMP/g dry weight) than C. sorokiniana during Period II pseudo steady state. The removal decreased drastically in Period III due to overgrowth of filamentous green algae. This study shows for the first time how microbial community composition and abundance are key for OMPs removal.
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Affiliation(s)
- Kaiyi Wu
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands; Sub-department of Environmental Technology, Wageningen University, PO box 8129, 6700 EV Wageningen, The Netherlands
| | - Tino Leliveld
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands; Sub-department of Environmental Technology, Wageningen University, PO box 8129, 6700 EV Wageningen, The Netherlands
| | - Hans Zweers
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands
| | - Huub Rijnaarts
- Sub-department of Environmental Technology, Wageningen University, PO box 8129, 6700 EV Wageningen, The Netherlands
| | - Alette Langenhoff
- Sub-department of Environmental Technology, Wageningen University, PO box 8129, 6700 EV Wageningen, The Netherlands
| | - Tânia V Fernandes
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands.
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3
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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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4
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Effects of Phycosphere Bacteria on Their Algal Host Are Host Species-Specific and Not Phylogenetically Conserved. Microorganisms 2022; 11:microorganisms11010062. [PMID: 36677355 PMCID: PMC9862884 DOI: 10.3390/microorganisms11010062] [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: 12/09/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
Phytoplankton is fundamental to life on Earth. Their productivity is influenced by the microbial communities residing in the phycosphere surrounding algal cells. Expanding our knowledge on how algal-bacterial interactions affect algal growth to more hosts and bacteria can help elucidate general principles of algal-host interactions. Here, we isolated 368 bacterial strains from phycosphere communities, right after phycosphere recruitment from pond water and after a month of lab cultivation and examined their impacts on growth of five green algal species. We isolated both abundant and rare phycosphere members, representing 18.4% of the source communities. Positive and neutral effects predominated over negative effects on host growth. The proportion of each effect type and whether the day of isolation mattered varied by host species. Bacteria affected algal carrying capacity more than growth rate, suggesting that nutrient remineralization and toxic byproduct metabolism may be a dominant mechanism. Across-host algal fitness assays indicated host-specific growth effects of our isolates. We observed no phylogenetic conservation of the effect on host growth among bacterial isolates. Even isolates with the same ASV had divergent effects on host growth. Our results emphasize highly specific host-bacterial interactions in the phycosphere and raise questions as to which mechanisms mediate these interactions.
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Mao L, Huang J, Mao H, Xu M, Zhang W. Self-floating capsule of algicidal bacteria Bacillus sp. HL and its performance in the dissolution of Microcystis aeruginosa. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 320:115837. [PMID: 35933879 DOI: 10.1016/j.jenvman.2022.115837] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Algicidal bacteria is considered as an efficient and environmentally friendly approach to suppress Microcystis aeruginosa (M. aeruginosa). However, algicidal bacteria in natural water is limited during the practical application due to the interference of external factors and the low reuse capability. In this study, a bio-degradation capsule for M. aeruginosa is prepared by bio-compatible sodium alginate (SA) compositing with eco-friendly ethyl cellulose (EC) to improve the property and reuse capability of algicidal bacteria. Bacterial strain HL was well immobilized and the capsule was obtained with 2% of SA, 3% of calcium chloride (CaCl2) and 3% of EC. It has been proved that capsules immobilizing bacteria HL shows considerable advantage over traditional bio-treatment systems (free-living bacteria) and good reusable performance. A better algicidal rate of 77.67% ± 1.14% at 7th day was obtained with the use of capsule embedding 50 mL of algicidal bacteria, enhanced by 11.05% comparing with same amount of free-living bacteria. Moreover, the algicidal rate of M. aeruginosa still reached 68.57% ± 2.88% after three times repetitive use. The effect of capsules on the fluorescence and antioxidant system of M. aeruginosa indicated that the photosystems were irreversibly damaged and the antioxidant response of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were significantly induced. Overall, capsules prepared in this study can provide a desirable environment for algicidal bacteria HL and ensure algicidal bacteria to in-situ work well in inhibiting booms of algae.
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Affiliation(s)
- Linqiang Mao
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, Jiangsu Province, 213164, China.
| | - Jinjie Huang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, Jiangsu Province, 213164, China
| | - Hongyan Mao
- Shandong Vocational Animal Science and Veterinary College, Weifang, Shandong Province, 261061, China
| | - Mingchen Xu
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, Jiangsu Province, 213164, China
| | - Wenyi Zhang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, Jiangsu Province, 213164, China.
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Akbar S, Li X, Ding Z, Liu Q, Huang J, Zhou Q, Gu L, Yang Z. Disentangling Diet- and Medium-Associated Microbes in Shaping Daphnia Gut Microbiome. MICROBIAL ECOLOGY 2022; 84:911-921. [PMID: 34714368 DOI: 10.1007/s00248-021-01900-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 10/11/2021] [Indexed: 05/09/2023]
Abstract
Host genotype and environment are considered crucial factors in shaping Daphnia gut microbiome composition. Among the environmental factors, diet is an important factor that regulates Daphnia microbiome. Most of the studies only focused on the use of axenic diet and non-sterile medium to investigate their effects on Daphnia microbiome. However, in natural environment, Daphnia diets such as phytoplankton are associated with microbes and could affect Daphnia microbiome composition and fitness, but remain relatively poorly understood compared to that of axenic diet. To test this, we cultured two Daphnia magna genotypes (genotype-1 and genotype-2) in sterile medium and fed with axenic diet. To check the effects of algal diet-associated microbes versus free water-related microbes, Daphnia were respectively inoculated with three different inoculums: medium microbial inoculum, diet-associated microbial inoculum, and medium and diet-mixed microbial inoculum. Daphnia were cultured for 3 weeks and their gut microbiome and life history traits were recorded. Results showed that Daphnia inoculated with medium microbial inoculum were dominated by Comamonadaceae in both genotypes. In Daphnia inoculated with mixed inoculum, genotype-1 microbiome was highly changed, whereas genotype-2 microbiome was slightly altered. Daphnia inoculated with diet microbial inoculum has almost the same microbiome in both genotypes. The total number of neonates and body size were significantly reduced in Daphnia inoculated with diet microbial inoculum regardless of genotype compared to all other treatments. Overall, this study shows that the microbiome of Daphnia is flexible and varies with genotype and diet- and medium-associated microbes, but not every bacteria is beneficial to Daphnia, and only symbionts can increase Daphnia performance.
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Affiliation(s)
- Siddiq Akbar
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Xianxian Li
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Zihao Ding
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Qi Liu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Jing Huang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Qiming Zhou
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Lei Gu
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Zhou Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
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7
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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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Xiao Y, Chen J, Chen M, Deng SJ, Xiong ZQ, Tian BY, Zhang BH. Mycolicibacterium lacusdiani sp. nov., an Attached Bacterium of Microcystis aeruginosa. Front Microbiol 2022; 13:861291. [PMID: 35633692 PMCID: PMC9134240 DOI: 10.3389/fmicb.2022.861291] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/11/2022] [Indexed: 11/24/2022] Open
Abstract
In eutrophic water, attached bacteria of Microcystis play an important role in the formation, development, and degradation of Microcystis blooms. A novel actinobacterium, designated as JXJ CY 35T, was isolated from the culture mass of Microcystis aeruginosa FACHB-905 (Maf) collected from Lake Dianchi, Yunnan Province, China. Strain JXJ CY 35T was gram-positive, acid-fast staining, aerobic, with short rod-shaped cells, positive for catalase, and negative for oxidase. The isolate was able to grow at 10.0–36.0°C, pH 4.0–10.0, and tolerate up to 5.0% (w/v) NaCl, with optimal growth at 28°C, pH 7.0–8.0, and 0% (w/v) NaCl. Cell-wall peptidoglycan contains aspartic acid, glutamic acid, glycine, and alanine, with mannose, ribose, galactose, and arabinose as whole-cell sugars. Polar lipids consist of diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), glycolipid (GL1-3), phosphoglycolipid (PGL), phosphatidylinositol (PI), and unidentified lipid (L1). The predominant menaquinone was MK-9. Major fatty acids (>10%) were C17:1ω7c (37.0%) and C18:1ω9c (18.9%). The complete genome sequence of strain JXJ CY 35T was 6,138,096 bp in size with a DNA G + C content of 68.3%. Based on 16S rRNA gene sequences, it has 98.2% similarity to Mycolicibacterium arabiense JCM 18538T. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain JXJ CY 35T and the closest five type strains M. arabiense JCM 18538T, M. goodii ATCC 700504T, M. mageritense DSM 44476T, M. austroafricanum DSM 44191T, and Mycobacterium neglectum CECT 8778T were 52.1, 20.3, 20.3, 20.6, and 19.8%, and 92.7, 75.5, 75.6, 76.0, and 75.2%, respectively. On the basis of the above taxonomic data and differences in physiological characteristics from the closely related type strain, strain JXJ CY 35T was determined to represent a novel species of genus Mycolicibacterium, for which the name Mycolicibacterium lacusdiani sp. nov., is proposed. The type strain is JXJ CY 35T (=KCTC 49379T = CGMCC 1.17501T). Different inoculation dosages of the type strain JXJ CY 35T could exhibit different effects on the growth of Maf and its toxin synthesis and release. Strain JXJ CY 35T could promote the growth of Maf by providing it with available phosphorus, nitrogen, probably vitamins, and plant growth hormones.
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Affiliation(s)
- Yao Xiao
- College of Pharmacy and Life Science, Jiujiang University, Jiujiang, China
- College of Life Science, Fujian Normal University, Fuzhou, China
| | - Jian Chen
- College of Pharmacy and Life Science, Jiujiang University, Jiujiang, China
| | - Min Chen
- College of Pharmacy and Life Science, Jiujiang University, Jiujiang, China
| | - Shao-Ji Deng
- College of Pharmacy and Life Science, Jiujiang University, Jiujiang, China
| | - Zhi-Qian Xiong
- College of Pharmacy and Life Science, Jiujiang University, Jiujiang, China
| | - Bao-Yu Tian
- College of Life Science, Fujian Normal University, Fuzhou, China
| | - Bing-Huo Zhang
- College of Pharmacy and Life Science, Jiujiang University, Jiujiang, China
- *Correspondence: Bing-Huo Zhang
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9
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Gobler CJ, Jankowiak JG. Dynamic Responses of Endosymbiotic Microbial Communities Within Microcystis Colonies in North American Lakes to Altered Nitrogen, Phosphorus, and Temperature Levels. Front Microbiol 2022; 12:781500. [PMID: 35222297 PMCID: PMC8867038 DOI: 10.3389/fmicb.2021.781500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/23/2021] [Indexed: 11/29/2022] Open
Abstract
The toxic cyanobacterium, Microcystis, is a pervasive cyanobacterial harmful algal bloom (CHAB) - forming genus that naturally occurs in colonies that harbor diverse microbiomes of heterotrophic bacteria. While the effects of nutrient loading and climatic warming on CHABs are well-known, little is known regarding how these environmental drivers alter the structural and functional potential of the microbial assemblages associated with blooms that, in turn, may impact cyanobacterial growth. Here, we used next-generation sequencing of 16S ribosomal rRNA genes to characterize the dynamics of the bacterial assemblages within Microcystis colonies in two temperate North American lakes: Lake Erie and Lake Agawam (NY, United States) and quantified their responses to experimentally increased levels of nitrogen (N), phosphorus (P) and temperature. Across experiments, Microcystis populations were consistently and significantly promoted by N and, to a lesser extent, elevated temperature (p < 0.05). In contrast, bacterial assemblages within Microcystis colonies were more resilient to environmental perturbations, with the relative abundance of 7–16% of amplicon sequence variants changing and several individual taxa displaying significant (p < 0.05) increases and decreases in relative abundance, primarily in response to elevated temperature and to a lesser extent, N. In contrast to individual taxa, community diversity was not significantly altered by individual treatments during experiments but rather was inversely correlated with the intensity of Microcystis blooms (p < 0.001). While predicted metabolic function was even less impacted by environmental drivers than microbial diversity, the predicted abundance of nitrogenase (nifH), alkaline phosphatase (phoX), and urease (ure) genes significantly increased in response to N but decreased in response to increased temperature (p < 0.05). Collectively, the resilience of microbial community structure and function within colonies suggests they may support the ability of Microcystis to persist through short-term fluctuations in environmental conditions by supplying essential nutrients.
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10
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Pérez-Carrascal OM, Tromas N, Terrat Y, Moreno E, Giani A, Corrêa Braga Marques L, Fortin N, Shapiro BJ. Single-colony sequencing reveals microbe-by-microbiome phylosymbiosis between the cyanobacterium Microcystis and its associated bacteria. MICROBIOME 2021; 9:194. [PMID: 34579777 PMCID: PMC8477515 DOI: 10.1186/s40168-021-01140-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 08/02/2021] [Indexed: 05/26/2023]
Abstract
BACKGROUND Cyanobacteria from the genus Microcystis can form large mucilaginous colonies with attached heterotrophic bacteria-their microbiome. However, the nature of the relationship between Microcystis and its microbiome remains unclear. Is it a long-term, evolutionarily stable association? Which partners benefit? Here we report the genomic diversity of 109 individual Microcystis colonies-including cyanobacteria and associated bacterial genomes-isolated in situ and without culture from Lake Champlain, Canada and Pampulha Reservoir, Brazil. RESULTS We identified 14 distinct Microcystis genotypes from Canada, of which only two have been previously reported, and four genotypes specific to Brazil. Microcystis genetic diversity was much greater between than within colonies, consistent with colony growth by clonal expansion rather than aggregation of Microcystis cells. We also identified 72 bacterial species in the microbiome. Each Microcystis genotype had a distinct microbiome composition, and more closely related genotypes had more similar microbiomes. This pattern of phylosymbiosis could be explained by co-phylogeny in only two out of the nine most prevalent associated bacterial genera, Roseomonas and Rhodobacter. These phylogenetically associated genera could enrich the metabolic repertoire of Microcystis, for example by encoding the biosynthesis of complementary carotenoid molecules. In contrast, other colony-associated bacteria showed weaker signals of co-phylogeny, but stronger evidence of horizontal gene transfer with Microcystis. These observations suggest that acquired genes are more likely to be retained in both partners (Microcystis and members of its microbiome) when they are loosely associated, whereas one gene copy is sufficient when the association is physically tight and evolutionarily long-lasting. CONCLUSIONS We have introduced a method for culture-free isolation of single colonies from nature followed by metagenomic sequencing, which could be applied to other types of microbes. Together, our results expand the known genetic diversity of both Microcystis and its microbiome in natural settings, and support their long-term, specific, and potentially beneficial associations. Video Abstract.
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Affiliation(s)
| | - Nicolas Tromas
- Département de Sciences Biologiques, Université́ de Montréal, Montréal, Québec, Canada.
| | - Yves Terrat
- Département de Sciences Biologiques, Université́ de Montréal, Montréal, Québec, Canada
| | - Elisa Moreno
- Département de Sciences Biologiques, Université́ de Montréal, Montréal, Québec, Canada
| | - Alessandra Giani
- Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Nathalie Fortin
- National Research Council of Canada, Montreal, Québec, Canada
| | - B Jesse Shapiro
- Département de Sciences Biologiques, Université́ de Montréal, Montréal, Québec, Canada.
- Department of Microbiology & Immunology, McGill University, Montreal, Québec, Canada.
- McGill Genome Centre, McGill University, Montreal, Québec, Canada.
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11
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Sukenik A, Kaplan A. Cyanobacterial Harmful Algal Blooms in Aquatic Ecosystems: A Comprehensive Outlook on Current and Emerging Mitigation and Control Approaches. Microorganisms 2021; 9:1472. [PMID: 34361909 PMCID: PMC8306311 DOI: 10.3390/microorganisms9071472] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/04/2021] [Accepted: 07/06/2021] [Indexed: 12/31/2022] Open
Abstract
An intensification of toxic cyanobacteria blooms has occurred over the last three decades, severely affecting coastal and lake water quality in many parts of the world. Extensive research is being conducted in an attempt to gain a better understanding of the driving forces that alter the ecological balance in water bodies and of the biological role of the secondary metabolites, toxins included, produced by the cyanobacteria. In the long-term, such knowledge may help to develop the needed procedures to restore the phytoplankton community to the pre-toxic blooms era. In the short-term, the mission of the scientific community is to develop novel approaches to mitigate the blooms and thereby restore the ability of affected communities to enjoy coastal and lake waters. Here, we critically review some of the recently proposed, currently leading, and potentially emerging mitigation approaches in-lake novel methodologies and applications relevant to drinking-water treatment.
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Affiliation(s)
- Assaf Sukenik
- The Yigal Allon Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, P.O. Box 447, Migdal 14950, Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel;
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12
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Dick GJ, Duhaime MB, Evans JT, Errera RM, Godwin CM, Kharbush JJ, Nitschky HS, Powers MA, Vanderploeg HA, Schmidt KC, Smith DJ, Yancey CE, Zwiers CC, Denef VJ. The genetic and ecophysiological diversity of Microcystis. Environ Microbiol 2021; 23:7278-7313. [PMID: 34056822 DOI: 10.1111/1462-2920.15615] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/24/2021] [Accepted: 05/27/2021] [Indexed: 01/30/2023]
Abstract
Microcystis is a cyanobacterium that forms toxic blooms in freshwater ecosystems around the world. Biological variation among taxa within the genus is apparent through genetic and phenotypic differences between strains and via the spatial and temporal distribution of strains in the environment, and this fine-scale diversity exerts strong influence over bloom toxicity. Yet we do not know how varying traits of Microcystis strains govern their environmental distribution, the tradeoffs and links between these traits, or how they are encoded at the genomic level. Here we synthesize current knowledge on the importance of diversity within Microcystis and on the genes and traits that likely underpin ecological differentiation of taxa. We briefly review spatial and environmental patterns of Microcystis diversity in the field and genetic evidence for cohesive groups within Microcystis. We then compile data on strain-level diversity regarding growth responses to environmental conditions and explore evidence for variation of community interactions across Microcystis strains. Potential links and tradeoffs between traits are identified and discussed. The resulting picture, while incomplete, highlights key knowledge gaps that need to be filled to enable new models for predicting strain-level dynamics, which influence the development, toxicity and cosmopolitan nature of Microcystis blooms.
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Affiliation(s)
- Gregory J Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Melissa B Duhaime
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Jacob T Evans
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Reagan M Errera
- National Oceanographic and Atmospheric Administration Great Lakes Environmental Research Lab, Ann Arbor, MI, USA
| | - Casey M Godwin
- School for Environment and Sustainability, Cooperative Institute for Great Lakes Research, University of Michigan, Ann Arbor, MI, USA
| | - Jenan J Kharbush
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Helena S Nitschky
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - McKenzie A Powers
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Henry A Vanderploeg
- National Oceanographic and Atmospheric Administration Great Lakes Environmental Research Lab, Ann Arbor, MI, USA
| | - Kathryn C Schmidt
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Derek J Smith
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Colleen E Yancey
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Claire C Zwiers
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Vincent J Denef
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
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13
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Smith DJ, Tan JY, Powers MA, Lin XN, Davis TW, Dick GJ. Individual Microcystis colonies harbour distinct bacterial communities that differ by Microcystis oligotype and with time. Environ Microbiol 2021; 23:3020-3036. [PMID: 33830633 DOI: 10.1111/1462-2920.15514] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 03/11/2021] [Accepted: 04/06/2021] [Indexed: 12/31/2022]
Abstract
Interactions between bacteria and phytoplankton in the phycosphere have impacts at the scale of whole ecosystems, including the development of harmful algal blooms. The cyanobacterium Microcystis causes toxic blooms that threaten freshwater ecosystems and human health globally. Microcystis grows in colonies that harbour dense assemblages of other bacteria, yet the taxonomic composition of these phycosphere communities and the nature of their interactions with Microcystis are not well characterized. To identify the taxa and compositional variance within Microcystis phycosphere communities, we performed 16S rRNA V4 region amplicon sequencing on individual Microcystis colonies collected biweekly via high-throughput droplet encapsulation during a western Lake Erie cyanobacterial bloom. The Microcystis phycosphere communities were distinct from microbial communities in whole water and bulk phytoplankton seston in western Lake Erie but lacked 'core' taxa found across all colonies. However, dissimilarity in phycosphere community composition correlated with sampling date and the Microcystis 16S rRNA oligotype. Several taxa in the phycosphere were specific to and conserved with Microcystis of a single oligotype or sampling date. Together, this suggests that physiological differences between Microcystis strains, temporal changes in strain phenotypes, and the composition of seeding communities may impact community composition of the Microcystis phycosphere.
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Affiliation(s)
- Derek J Smith
- Department of Earth & Environmental Science, The University of Michigan, 1100 N. University Building, 1100 N. University Avenue, Ann Arbor, MI, 48109, USA
| | - James Y Tan
- Department of Chemical Engineering, The University of Michigan, NCRC, 2800 Plymouth Rd., Ann Abor, MI, 48109, USA
| | - McKenzie A Powers
- Department of Earth & Environmental Science, The University of Michigan, 1100 N. University Building, 1100 N. University Avenue, Ann Arbor, MI, 48109, USA
| | - Xiaoxia N Lin
- Department of Chemical Engineering, The University of Michigan, NCRC, 2800 Plymouth Rd., Ann Abor, MI, 48109, USA
| | - Timothy W Davis
- Department of Biological Sciences, Bowling Green State University, Life Sciences Building, Corner of N. College Dr and E. Merry Avenue, Bowling Green, OH, 43403, USA
| | - Gregory J Dick
- Department of Earth & Environmental Science, The University of Michigan, 1100 N. University Building, 1100 N. University Avenue, Ann Arbor, MI, 48109, USA
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