1
|
Romanis CS, Timms VJ, Nebauer DJ, Crosbie ND, Neilan BA. Microbiome analysis reveals Microcystis blooms endogenously seeded from benthos within wastewater maturation ponds. Appl Environ Microbiol 2024; 90:e0158523. [PMID: 38117057 PMCID: PMC10807444 DOI: 10.1128/aem.01585-23] [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: 09/14/2023] [Accepted: 10/27/2023] [Indexed: 12/21/2023] Open
Abstract
Toxigenic Microcystis blooms periodically disrupt the stabilization ponds of wastewater treatment plants (WWTPs). Dense proliferations of Microcystis cells within the surface waters (SWs) impede the water treatment process by reducing the treatment efficacy of the latent WWTP microbiome. Further, water quality is reduced when conventional treatment leads to Microcystis cell lysis and the release of intracellular microcystins into the water column. Recurrent seasonal Microcystis blooms cause significant financial burdens for the water industry and predicting their source is vital for bloom management strategies. We investigated the source of recurrent toxigenic Microcystis blooms at Australia's largest lagoon-based municipal WWTP in both sediment core (SC) and SW samples between 2018 and 2020. Bacterial community composition of the SC and SW samples according to 16S rRNA gene amplicon sequencing showed that Microcystis sp. was dominant within SW samples throughout the period and reached peak relative abundances (32%) during the summer. The same Microcystis Amplicon sequence variants were present within the SC and SW samples indicating a potential migratory population that transitions between the sediment water and SWs during bloom formation events. To investigate the potential of the sediment to act as a repository of viable Microcystis cells for recurrent bloom formation, a novel in-vitro bloom model was established featuring sediments and sterilized SW collected from the WWTP. Microcystin-producing Microcystis blooms were established through passive resuspension after 12 weeks of incubation. These results demonstrate the capacity of Microcystis to transition between the sediments and SWs in WWTPs, acting as a perennial inoculum for recurrent blooms.IMPORTANCECyanobacterial blooms are prevalent to wastewater treatment facilities owing to the stable, eutrophic conditions. Cyanobacterial proliferations can disrupt operational procedures through the blocking of filtration apparatus or altering the wastewater treatment plant (WWTP) microbiome, reducing treatment efficiency. Conventional wastewater treatment often results in the lysis of cyanobacterial cells and the release of intracellular toxins which pose a health risk to end users. This research identifies a potential seeding source of recurrent toxigenic cyanobacterial blooms within wastewater treatment facilities. Our results demonstrate the capacity of Microcystis to transition between the sediments and surface waters (SWs) of wastewater treatment ponds enabling water utilities to develop adequate monitoring and management strategies. Further, we developed a novel model to demonstrate benthic recruitment of toxigenic Microcystis under laboratory conditions facilitating future research into the genetic mechanisms behind bloom development.
Collapse
Affiliation(s)
- C. S. Romanis
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
| | - V. J. Timms
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
- ARC Centre of Excellence for Synthetic Biology, Callaghan, Australia
| | - D. J. Nebauer
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
| | | | - B. A. Neilan
- University of Newcastle, School of Environmental and Life Sciences, Callaghan, Australia
- ARC Centre of Excellence for Synthetic Biology, Callaghan, Australia
| |
Collapse
|
2
|
Khot V, Strous M, Dong X, Kiesser AK. Viral diversity and dynamics and CRISPR-Cas-mediated immunity in a robust alkaliphilic cyanobacterial consortium. Microbiol Spectr 2023; 11:e0221723. [PMID: 37819096 PMCID: PMC10715143 DOI: 10.1128/spectrum.02217-23] [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: 07/31/2023] [Accepted: 08/25/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Biotechnology applications utilizing the function of microbial communities have become increasingly important solutions as we strive for sustainable applications. Although viral infections are known to have a significant impact on microbial turnover and nutrient cycling, viral dynamics have remained largely overlooked in these engineered communities. Predatory perturbations to the functional stability of these microbial biotechnology applications must be investigated in order to design more robust applications. In this study, we closely examine virus-microbe dynamics in a model microbial community used in a biotechnology application. Our findings suggest that viral dynamics change significantly with environmental conditions and that microbial immunity may play an important role in maintaining functional stability. We present this study as a comprehensive template for other researchers interested in exploring predatory dynamics in engineered microbial communities.
Collapse
Affiliation(s)
- Varada Khot
- Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
| | - Xiaoli Dong
- Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
- Public Health Laboratory, Alberta Precision Laboratories, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Alyse K. Kiesser
- School of Engineering, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| |
Collapse
|
3
|
Zorz J, Paquette AJ, Gillis T, Kouris A, Khot V, Demirkaya C, De La Hoz Siegler H, Strous M, Vadlamani A. Coordinated proteome change precedes cell lysis and death in a mat-forming cyanobacterium. THE ISME JOURNAL 2023; 17:2403-2414. [PMID: 37914776 PMCID: PMC10689466 DOI: 10.1038/s41396-023-01545-3] [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: 05/25/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023]
Abstract
Cyanobacteria form dense multicellular communities that experience transient conditions in terms of access to light and oxygen. These systems are productive but also undergo substantial biomass turnover through cell death, supplementing heightened heterotrophic respiration. Here we use metagenomics and metaproteomics to survey the molecular response of a mat-forming cyanobacterium undergoing mass cell lysis after exposure to dark and anoxic conditions. A lack of evidence for viral, bacterial, or eukaryotic antagonism contradicts commonly held beliefs on the causative agent for cyanobacterial death during dense growth. Instead, proteogenomics data indicated that lysis likely resulted from a genetically programmed response triggered by a failure to maintain osmotic pressure in the wake of severe energy limitation. Cyanobacterial DNA was rapidly degraded, yet cyanobacterial proteins remained abundant. A subset of proteins, including enzymes involved in amino acid metabolism, peptidases, toxin-antitoxin systems, and a potentially self-targeting CRISPR-Cas system, were upregulated upon lysis, indicating possible involvement in the programmed cell death response. We propose this natural form of cell death could provide new pathways for controlling harmful algal blooms and for sustainable bioproduct production.
Collapse
Affiliation(s)
- Jackie Zorz
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada.
| | - Alexandre J Paquette
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Timber Gillis
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Angela Kouris
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
- Synergia Biotech Inc., Calgary, AB, Canada
| | - Varada Khot
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Cigdem Demirkaya
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada
| | | | - Marc Strous
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
| | - Agasteswar Vadlamani
- Department of Earth, Energy, and Environment, University of Calgary, Calgary, AB, Canada
- Synergia Biotech Inc., Calgary, AB, Canada
| |
Collapse
|
4
|
Laux M, Piroupo CM, Setubal JC, Giani A. The Raphidiopsis (= Cylindrospermopsis) raciborskii pangenome updated: Two new metagenome-assembled genomes from the South American clade. HARMFUL ALGAE 2023; 129:102518. [PMID: 37951618 DOI: 10.1016/j.hal.2023.102518] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/15/2023] [Accepted: 09/28/2023] [Indexed: 11/14/2023]
Abstract
Two Raphidiopsis (=Cylindrospermopsis) raciborskii metagenome-assembled genomes (MAGs) were recovered from two freshwater metagenomic datasets sampled in 2011 and 2012 in Pampulha Lake, a hypereutrophic, artificial, shallow reservoir, located in the city of Belo Horizonte (MG), Brazil. Since the late 1970s, the lake has undergone increasing eutrophication pressure, due to wastewater input, leading to the occurrence of frequent cyanobacterial blooms. The major difference observed between PAMP2011 and PAMP2012 MAGs was the lack of the saxitoxin gene cluster in PAMP2012, which also presented a smaller genome, while PAMP2011 presented the complete sxt cluster and all essential proteins and clusters. The pangenome analysis was performed with all Raphidiopsis/Cylindrospermopsis genomes available at NCBI to date, with the addition of PAMP2011 and PAMP2012 MAGs (All33 subset), but also without the South American strains (noSA subset), and only among the South American strains (SA10 and SA8 subsets). We observed a substantial increase in the core genome size for the 'noSA' subset, in comparison to 'All33' subset, and since the core genome reflects the closeness among the pangenome members, the results strongly suggest that the conservation level of the essential gene repertoire seems to be affected by the geographic origin of the strains being analyzed, supporting the existence of a distinct SA clade. The Raphidiopsis pangenome comprised a total of 7943 orthologous protein clusters, and the two new MAGs increased the pangenome size by 11%. The pangenome based phylogenetic relationships among the 33 analyzed genomes showed that the SA genomes clustered together with 99% bootstrap support, reinforcing the metabolic particularity of the Raphidiopsis South American clade, related to its saxitoxin producing unique ability, while also indicating a different evolutionary history due to its geographic isolation.
Collapse
Affiliation(s)
- Marcele Laux
- Department of Botany, Phycology Laboratory, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil
| | - Carlos Morais Piroupo
- Department of Biochemistry, Institute of Chemistry, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil
| | - João Carlos Setubal
- Department of Biochemistry, Institute of Chemistry, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil
| | - Alessandra Giani
- Department of Botany, Phycology Laboratory, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil.
| |
Collapse
|
5
|
Moran JJ, Bernstein HC, Mobberley JM, Thompson AM, Kim YM, Dana KL, Cory AB, Courtney S, Renslow RS, Fredrickson JK, Kreuzer HW, Lipton MS. Daylight-driven carbon exchange through a vertically structured microbial community. Front Microbiol 2023; 14:1139213. [PMID: 37303779 PMCID: PMC10251406 DOI: 10.3389/fmicb.2023.1139213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Interactions between autotrophs and heterotrophs are central to carbon (C) exchange across trophic levels in essentially all ecosystems and metabolite exchange is a frequent mechanism for distributing C within spatially structured ecosystems. Yet, despite the importance of C exchange, the timescales at which fixed C is transferred in microbial communities is poorly understood. We employed a stable isotope tracer combined with spatially resolved isotope analysis to quantify photoautotrophic uptake of bicarbonate and track subsequent exchanges across a vertical depth gradient in a stratified microbial mat over a light-driven diel cycle. We observed that C mobility, both across the vertical strata and between taxa, was highest during periods of active photoautotrophy. Parallel experiments with 13C-labeled organic substrates (acetate and glucose) showed comparably less exchange of C within the mat. Metabolite analysis showed rapid incorporation of 13C into molecules that can both comprise a portion of the extracellular polymeric substances in the system and serve to transport C between photoautotrophs and heterotrophs. Stable isotope proteomic analysis revealed rapid C exchange between cyanobacterial and associated heterotrophic community members during the day with decreased exchange at night. We observed strong diel control on the spatial exchange of freshly fixed C within tightly interacting mat communities suggesting a rapid redistribution, both spatially and taxonomically, primarily during daylight periods.
Collapse
Affiliation(s)
- James J. Moran
- Pacific Northwest National Laboratory, Richland, WA, United States
- Department of Integrative Biology, Michigan State University, East Lansing, MI, United States
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Hans C. Bernstein
- Pacific Northwest National Laboratory, Richland, WA, United States
- Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø, Norway
- ARC – The Arctic Centre for Sustainable Energy, UiT The Arctic University of Norway, Tromsø, Norway
| | | | | | - Young-Mo Kim
- Pacific Northwest National Laboratory, Richland, WA, United States
| | - Karl L. Dana
- Pacific Northwest National Laboratory, Richland, WA, United States
| | | | - Steph Courtney
- Pacific Northwest National Laboratory, Richland, WA, United States
| | - Ryan S. Renslow
- Pacific Northwest National Laboratory, Richland, WA, United States
| | | | - Helen W. Kreuzer
- Pacific Northwest National Laboratory, Richland, WA, United States
| | - Mary S. Lipton
- Pacific Northwest National Laboratory, Richland, WA, United States
| |
Collapse
|
6
|
Trebuch LM, Bourceau OM, Vaessen SMF, Neu TR, Janssen M, de Beer D, Vet LEM, Wijffels RH, Fernandes TV. High resolution functional analysis and community structure of photogranules. THE ISME JOURNAL 2023; 17:870-879. [PMID: 36997724 DOI: 10.1038/s41396-023-01394-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 03/31/2023]
Abstract
AbstractPhotogranules are spherical aggregates formed of complex phototrophic ecosystems with potential for “aeration-free” wastewater treatment. Photogranules from a sequencing batch reactor were investigated by fluorescence microscopy, 16S/18S rRNA gene amplicon sequencing, microsensors, and stable- and radioisotope incubations to determine the granules’ composition, nutrient distribution, and light, carbon, and nitrogen budgets. The photogranules were biologically and chemically stratified, with filamentous cyanobacteria arranged in discrete layers and forming a scaffold to which other organisms were attached. Oxygen, nitrate, and light gradients were also detectable. Photosynthetic activity and nitrification were both predominantly restricted to the outer 500 µm, but while photosynthesis was relatively insensitive to the oxygen and nutrient (ammonium, phosphate, acetate) concentrations tested, nitrification was highly sensitive. Oxygen was cycled internally, with oxygen produced through photosynthesis rapidly consumed by aerobic respiration and nitrification. Oxygen production and consumption were well balanced. Similarly, nitrogen was cycled through paired nitrification and denitrification, and carbon was exchanged through photosynthesis and respiration. Our findings highlight that photogranules are complete, complex ecosystems with multiple linked nutrient cycles and will aid engineering decisions in photogranular wastewater treatment.
Collapse
|
7
|
Wang X, Wang K, Wang L, Luo H, Wang Y, Wang Y, Tu T, Qin X, Su X, Bai Y, Yao B, Huang H, Zhang J. Engineering Cupriavidus necator H16 for heterotrophic and autotrophic production of myo-inositol. BIORESOURCE TECHNOLOGY 2023; 368:128321. [PMID: 36379295 DOI: 10.1016/j.biortech.2022.128321] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
Bioconversion of sustainable feedstocks to commodity chemicals is considered as an effective solution for transforming the fossil-based economy into a carbon-neutral model. Here, the CO2-fixing bacterium Cupriavidus necator H16 was exploited for myo-inositol production from renewable substrates. First, by introducing the glucose transportation system, the glucose consumption route was established. Second, two key enzymes involved in myo-inositol biosynthesis were screened and evaluated. A myo-inositol-producing strain was constructed via overexpression of myo-inositol-3-phosphate synthase from Saccharomyces cerevisiae and inositol monophosphatase from Escherichia coli. Finally, carbon flux redirection was achieved through disruption of Entner-Doudoroff pathway and poly(3-hydroxybutyrate) synthesis pathway, resulting in a final myo-inositol production of 520.2, 1076.3 and 1054.8 mg/L from glucose, glycerol and CO2, respectively. The myo-inositol production level from CO2 achieved here set up the record. This study underlines the potential of C. necator to be utilized as microbial factory for upcycling the renewable feedstocks and CO2 to high-value biochemicals.
Collapse
Affiliation(s)
- Xiaolu Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Kaikai Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lei Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Institute of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yaru Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xing Qin
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaoyun Su
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yingguo Bai
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jie Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| |
Collapse
|
8
|
Paquette AJ, Vadlamani A, Demirkaya C, Strous M, De la Hoz Siegler H. Nutrient management and medium reuse for cultivation of a cyanobacterial consortium at high pH and alkalinity. Front Bioeng Biotechnol 2022; 10:942771. [PMID: 36032714 PMCID: PMC9402938 DOI: 10.3389/fbioe.2022.942771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Alkaliphilic cyanobacteria have gained significant interest due to their robustness, high productivity, and ability to convert CO2 into bioenergy and other high value products. Effective nutrient management, such as re-use of spent medium, will be essential to realize sustainable applications with minimal environmental impacts. In this study, we determined the solubility and uptake of nutrients by an alkaliphilic cyanobacterial consortium grown at high pH and alkalinity. Except for Mg, Ca, Co, and Fe, all nutrients are in fully soluble form. The cyanobacterial consortium grew well without any inhibition and an overall productivity of 0.15 g L−1 d−1 (AFDW) was achieved. Quantification of nutrient uptake during growth resulted in the empirical formula CH1.81N0.17O0.20P0.013S0.009 for the consortium biomass. We showed that spent medium can be reused for at least five growth/harvest cycles. After an adaptation period, the cyanobacterial consortium fully acclimatized to the spent medium, resulting in complete restoration of biomass productivity.
Collapse
Affiliation(s)
- Alexandre J. Paquette
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
- *Correspondence: Alexandre J. Paquette,
| | | | - Cigdem Demirkaya
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB, Canada
| | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | | |
Collapse
|
9
|
Haines M, Vadlamani A, Daniel Loty Richardson W, Strous M. Pilot-scale outdoor trial of a cyanobacterial consortium at pH 11 in a photobioreactor at high latitude. BIORESOURCE TECHNOLOGY 2022; 354:127173. [PMID: 35452822 DOI: 10.1016/j.biortech.2022.127173] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
The biomass of microalgae and cyanobacteria yields a variety of products. Outdoor pilot plant trials typically grow a single species at circumneutral pH and provide CO2 by gas sparging. Here a cyanobacterial consortium was grown at high pH (beyond 11) and high dissolved carbonate concentrations (0.5 M) in an outdoor 1,150 L tubular photobioreactor for 130 days in Calgary, Canada. The aim was to assess the productivity and robustness of the consortium. Importantly, the system was designed to enable future integration of air capture of CO2. Productivity was between 3.1 and 5.8 g ash-free dry weight per square metre per day, depending on biomass density and month. 16S rRNA amplicon sequencing showed that cyanobacterium Candidatus "Phormidium alkaliphilum" made up 80% of the consortium. The consortium displayed robust growth and adapted to environmental conditions. Bicarbonate uptake pushed medium pH past 11, demonstrating the ability to achieve CO2 delivery by air capture.
Collapse
Affiliation(s)
- Marianne Haines
- Department of Geoscience, University of Calgary, Calgary, Alberta, Canada.
| | | | | | - Marc Strous
- Department of Geoscience, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|