1
|
Temperature-dependent resistance to starvation of three contrasting freshwater ciliates. Eur J Protistol 2023; 88:125973. [PMID: 36989877 DOI: 10.1016/j.ejop.2023.125973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/26/2023] [Accepted: 03/08/2023] [Indexed: 03/17/2023]
Abstract
We investigated the temperature-dependent response to starvation of three contrasting freshwater ciliates (Ciliophora). The cyst-forming algivorous species Meseres corlissi and the bactivorous species Glaucomides bromelicola, which cannot form cysts, co-occur in the reservoirs (tanks) of tree bromeliads. The mixotrophic species Coleps spetai is common in many lakes. We hypothesized that the ciliates' different traits and life strategies would affect their survival rates and temperature sensitivity under food depleted conditions. We measured the decline of the ciliate populations in microcosm experiments at different temperatures for several days. We used an imaging flow cytometer to size the ciliates and documented their morphological and physiological changes in response to starvation. We found that the cyst-forming species had the highest mortality rates but may endure long-term starvation by encystment. The sympatric, non-encysting species suffered the lowest mortality rates and could survive for more than three weeks without food. The mixotrophic species had intermediate mortality rates but showed the highest phenotypic plasticity in response to starvation. A significant fraction of the C. spetai population appeared unaffected by starvation, suggesting that the endosymbionts provided some resources to the host cells. The mean mortality rate per day of all three species increased with temperature by 0.09 °C-1.
Collapse
|
2
|
Wang J, Wang Y, Lai J, Li J, Yu K. Improvement and application of qPCR assay revealed new insight on early warning of Phaeocystis globosa bloom. WATER RESEARCH 2023; 229:119439. [PMID: 36473412 DOI: 10.1016/j.watres.2022.119439] [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: 08/01/2022] [Revised: 11/21/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Phaeocystis globosa bloom develops from its early solitary cells, providing clues for early warning of its bloom and timely responding to possible consequences. However, the early prediction requires quantification of the solitary cells for a thorough understanding of bloom formation. Therefore, we developed an accurate, sensitive, and specific qPCR assay for this need. Results show that the accuracy of qPCR was significantly enhanced by ameliorating DNA barcode design, improving genomic DNA extraction, and introducing a strategy of internal amplification control (IAC). This approach reached a quantification limit of 1 cell/reaction, making low-abundance cells (101-103 cells/L) detection possible, and we also observed a plunge in the abundance of the solitary cells before the bloom outbreak in two winters in 2019 and 2020 for the first time, which is quite unique from laboratory results showing an increase instead. The plunge in solitary-cell abundance might be associated with the attachment of solitary cells to solid matrices to form non-solitary attached aggregate, the precursor of colonies, which gains supports from other studies and needs more investigations in the future. Therefore, as the plunge in solitary-cell abundance is a sign of colony formation, it can be used as an early warning indicator to P. globosa bloom.
Collapse
Affiliation(s)
- Jiale Wang
- School of Marine Science, Guangxi Laboratory on the Study of Coral Reef in the South China Sea and Coral Reef Research Center of China, Guangxi University, Nanning 530004, China
| | - Yinghui Wang
- School of Marine Science, Guangxi Laboratory on the Study of Coral Reef in the South China Sea and Coral Reef Research Center of China, Guangxi University, Nanning 530004, China.
| | - Junxiang Lai
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Beibu Gulf Marine Research Center and Guangxi Academy of Sciences, Nanning 530007, China.
| | - Jie Li
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Beibu Gulf Marine Research Center and Guangxi Academy of Sciences, Nanning 530007, China
| | - Kefu Yu
- School of Marine Science, Guangxi Laboratory on the Study of Coral Reef in the South China Sea and Coral Reef Research Center of China, Guangxi University, Nanning 530004, China
| |
Collapse
|
3
|
Amalfitano S, Levantesi C, Copetti D, Stefani F, Locantore I, Guarnieri V, Lobascio C, Bersani F, Giacosa D, Detsis E, Rossetti S. Water and microbial monitoring technologies towards the near future space exploration. WATER RESEARCH 2020; 177:115787. [PMID: 32315899 DOI: 10.1016/j.watres.2020.115787] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 06/11/2023]
Abstract
Space exploration is demanding longer lasting human missions and water resupply from Earth will become increasingly unrealistic. In a near future, the spacecraft water monitoring systems will require technological advances to promptly identify and counteract contingent events of waterborne microbial contamination, posing health risks to astronauts with lowered immune responsiveness. The search for bio-analytical approaches, alternative to those applied on Earth by cultivation-dependent methods, is pushed by the compelling need to limit waste disposal and avoid microbial regrowth from analytical carryovers. Prospective technologies will be selected only if first validated in a flight-like environment, by following basic principles, advantages, and limitations beyond their current applications on Earth. Starting from the water monitoring activities applied on the International Space Station, we provide a critical overview of the nucleic acid amplification-based approaches (i.e., loop-mediated isothermal amplification, quantitative PCR, and high-throughput sequencing) and early-warning methods for total microbial load assessments (i.e., ATP-metry, flow cytometry), already used at a high readiness level aboard crewed space vehicles. Our findings suggest that the forthcoming space applications of mature technologies will be necessarily bounded by a compromise between analytical performances (e.g., speed to results, identification depth, reproducibility, multiparametricity) and detrimental technical requirements (e.g., reagent usage, waste production, operator skills, crew time). As space exploration progresses toward extended missions to Moon and Mars, miniaturized systems that also minimize crew involvement in their end-to-end operation are likely applicable on the long-term and suitable for the in-flight water and microbiological research.
Collapse
Affiliation(s)
- Stefano Amalfitano
- Water Research Institute - National Research Council of Italy (IRSA-CNR), Via Salaria Km 29,300, 00015, Monterotondo, Roma, Italy.
| | - Caterina Levantesi
- Water Research Institute - National Research Council of Italy (IRSA-CNR), Via Salaria Km 29,300, 00015, Monterotondo, Roma, Italy
| | - Diego Copetti
- Water Research Institute - National Research Council of Italy (IRSA-CNR), Via del Mulino 19, 20861, Brugherio, Monza-Brianza, Italy
| | - Fabrizio Stefani
- Water Research Institute - National Research Council of Italy (IRSA-CNR), Via del Mulino 19, 20861, Brugherio, Monza-Brianza, Italy
| | - Ilaria Locantore
- Thales Alenia Space Italia SpA, Strada Antica di Collegno, 253 - 10146, Turin, Italy
| | - Vincenzo Guarnieri
- Thales Alenia Space Italia SpA, Strada Antica di Collegno, 253 - 10146, Turin, Italy
| | - Cesare Lobascio
- Thales Alenia Space Italia SpA, Strada Antica di Collegno, 253 - 10146, Turin, Italy
| | - Francesca Bersani
- Centro Ricerche SMAT, Società Metropolitana Acque Torino S.p.A., C.so Unità d'Italia 235/3, 10127, Torino, Italy
| | - Donatella Giacosa
- Centro Ricerche SMAT, Società Metropolitana Acque Torino S.p.A., C.so Unità d'Italia 235/3, 10127, Torino, Italy
| | - Emmanouil Detsis
- European Science Foundation, 1 quai Lezay Marnésia, BP 90015, 67080, Strasbourg Cedex, France
| | - Simona Rossetti
- Water Research Institute - National Research Council of Italy (IRSA-CNR), Via Salaria Km 29,300, 00015, Monterotondo, Roma, Italy
| |
Collapse
|
4
|
Oloketuyi S, Mazzega E, Zavašnik J, Pungjunun K, Kalcher K, de Marco A, Mehmeti E. Electrochemical immunosensor functionalized with nanobodies for the detection of the toxic microalgae Alexandrium minutum using glassy carbon electrode modified with gold nanoparticles. Biosens Bioelectron 2020; 154:112052. [PMID: 32056958 DOI: 10.1016/j.bios.2020.112052] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 01/22/2020] [Accepted: 01/24/2020] [Indexed: 12/28/2022]
Abstract
In this work an electrochemical immunosensor for the toxic microalgae Alexandrium minutum (A. minutum AL9T) detection is described. A glassy carbon electrode (GCE) was modified by depositing gold nanoparticles followed by L-cysteine for obtaining a self-assembled monolayer. The SpyTagged nanobody C1, specific for the A. minutum toxic strain AL9T, was then covalently immobilized via SpyCatcher on the surface of the modified electrode and used for the selective capture of such microalgae strain. Electrochemical impedance spectroscopy (EIS) was used for the quantification of A. minutum cells present in water samples by measuring the charge-transfer resistance changes of the electrode with a hexacyanoferrate probe. Each electrode modification step was accompanied by cyclic voltammetry (CV) and scanning electron microscopy (SEM). The immunosensor provided highly reproducible data, was simple to fabricate at low cost, exhibited higher sensitivity than previously described alternative diagnostic methods and showed a broad linear range between 103 and 109 cells L-1 with detection limit of 3 × 103 cells L-1 of A. minutum AL9T. The immunosensor was successfully applied to quantify A. minutum AL9T in seawater and brackish water samples proving that it can be used for early detection of harmful microalgae without the necessity of pre-concentration or dialysis steps.
Collapse
Affiliation(s)
- Sandra Oloketuyi
- Laboratory of Environmental and Life Sciences, University of Nova Gorica, Vipavska cesta 13, SI-5000, Rožna Dolina (Nova Gorica), Slovenia
| | - Elisa Mazzega
- Laboratory of Environmental and Life Sciences, University of Nova Gorica, Vipavska cesta 13, SI-5000, Rožna Dolina (Nova Gorica), Slovenia
| | - Janez Zavašnik
- Department for Nanostructured Materials, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Kingkan Pungjunun
- Electrochemistry and Optical Spectroscopy Center of Excellence (EOSCE), Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok, 10330, Thailand
| | - Kurt Kalcher
- Institute of Chemistry, Analytical Chemistry, Karl-Franzens University, Universitätsplatz 1, Graz, A-8010, Austria
| | - Ario de Marco
- Laboratory of Environmental and Life Sciences, University of Nova Gorica, Vipavska cesta 13, SI-5000, Rožna Dolina (Nova Gorica), Slovenia.
| | - Eda Mehmeti
- Institute of Chemistry, Analytical Chemistry, Karl-Franzens University, Universitätsplatz 1, Graz, A-8010, Austria.
| |
Collapse
|
5
|
Weisse T, Moser M. Light affects picocyanobacterial grazing and growth response of the mixotrophic flagellate Poterioochromonas malhamensis. J Microbiol 2020; 58:268-278. [PMID: 31989545 DOI: 10.1007/s12275-020-9567-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/19/2019] [Accepted: 12/19/2019] [Indexed: 11/28/2022]
Abstract
We measured the grazing and growth response of the mixotrophic chrysomonad flagellate Poterioochromonas malhamensis on four closely related picocyanobacterial strains isolated from subalpine lakes in central Europe. The picocyanobacteria represented different pigment types (phycoerythrin-rich, PE, and phycocyanin-rich, PC) and phylogenetic clusters. The grazing experiments were conducted with laboratory cultures acclimated to 10 µmol photon/m2/sec (low light, LL) and 100 µmol photon/m2/sec (moderate light, ML), either in the dark or at four different irradiances ranging from low (6 µmol photon/m2/sec) to high (1,500 µmol photon/m2/sec) light intensity. Poterioochromonas malhamensis preferred the larger, green PC-rich picocyanobacteria to the smaller, red PE-rich picocyanobacterial, and heterotrophic bacteria. The feeding and growth rates of P. malhamensis were sensitive to the actual light conditions during the experiments; the flagellate performed relatively better in the dark and at LL conditions than at high light intensity. In summary, our results found strain-specific ingestion and growth rates of the flagellate; an effect of the preculturing conditions, and, unexpectedly, a direct adverse effect of high light levels. We conclude that this flagellate may avoid exposure to high surface light intensities commonly encountered in temperate lakes during the summer.
Collapse
Affiliation(s)
- Thomas Weisse
- University of Innsbruck, Research Department for Limnology, Mondseestr. 9, A-5310, Mondsee, Austria.
| | - Michael Moser
- University of Innsbruck, Research Department for Limnology, Mondseestr. 9, A-5310, Mondsee, Austria
| |
Collapse
|
6
|
Wirth C, Limberger R, Weisse T. Temperature × light interaction and tolerance of high water temperature in the planktonic freshwater flagellates Cryptomonas (Cryptophyceae) and Dinobryon (Chrysophyceae). JOURNAL OF PHYCOLOGY 2019; 55:404-414. [PMID: 30556585 PMCID: PMC6590229 DOI: 10.1111/jpy.12826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
Using microcosm experiments, we investigated the interactive effects of temperature and light on specific growth rates of three species each of the phytoplanktonic genera Cryptomonas and Dinobryon. Several species of these genera play important roles in the food web of lakes and seem to be sensitive to high water temperature. We measured growth rates at three to four photon flux densities ranging from 10 to 240 μmol photon · m-2 · s-1 and at 4-5 temperatures ranging from 10°C to 28°C. The temperature × light interaction was generally strong, species specific, and also genus specific. Five of the six species studied tolerated 25°C when light availability was high; however, low light reduced tolerance of high temperatures. Growth rates of all six species were unaffected by temperature in the 10°C-15°C range at light levels ≤50 μmol photon · m-2 · s-1 . At high light, growth rates of Cryptomonas spp. increased with temperature until the temperature optimum was reached and then declined. The Dinobryon species were less sensitive than Cryptomonas spp. to photon flux densities of 40 μmol photon · m-2 · s-1 and 200 μmol photon · m-2 · s-1 over the entire temperature range but did not grow under a combination of very low light (10 μmol photon · m-2 · s-1 ) and high temperature (≥20°C). Among the three Cryptomonas species, cell volume declined with temperature and the maximum temperature tolerated was negatively related to cell size. Since Cryptomonas is important food for microzooplankton, these trends may affect the pelagic carbon flow if lake warming continues.
Collapse
Affiliation(s)
- Christina Wirth
- Research Department for LimnologyUniversity of InnsbruckMondseestr. 95310MondseeAustria
| | - Romana Limberger
- Research Department for LimnologyUniversity of InnsbruckMondseestr. 95310MondseeAustria
| | - Thomas Weisse
- Research Department for LimnologyUniversity of InnsbruckMondseestr. 95310MondseeAustria
| |
Collapse
|