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Fisher A, Wangpraseurt D, Larkum AWD, Johnson M, Kühl M, Chen M, Wong HL, Burns BP. Correlation of bio-optical properties with photosynthetic pigment and microorganism distribution in microbial mats from Hamelin Pool, Australia. FEMS Microbiol Ecol 2019; 95:5151331. [PMID: 30380056 DOI: 10.1093/femsec/fiy219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/30/2018] [Indexed: 11/14/2022] Open
Abstract
Microbial mats and stromatolites are widespread in Hamelin Pool, Shark Bay, however the phototrophic capacity of these systems is unknown. This study has determined the optical properties and light-harvesting potential of these mats with light microsensors. These characteristics were linked via a combination of 16S rDNA sequencing, pigment analyses and hyperspectral imaging. Local scalar irradiance was elevated over the incident downwelling irradiance by 1.5-fold, suggesting light trapping and strong scattering by the mats. Visible light (400-700 nm) penetrated to a depth of 2 mm, whereas near-infrared light (700-800 nm) penetrated to at least 6 mm. Chlorophyll a and bacteriochlorophyll a (Bchl a) were found to be the dominant photosynthetic pigments present, with BChl a peaking at the subsurface (2-4 mm). Detailed 16S rDNA analyses revealed the presence of putative Chl f-containing Halomicronema sp. and photosynthetic members primarily decreased from the mat surface down to a depth of 6 mm. Data indicated high abundances of some pigments and phototrophic organisms in deeper layers of the mats (6-16 mm). It is proposed that the photosynthetic bacteria present in this system undergo unique adaptations to lower light conditions below the mat surface, and that phototrophic metabolisms are major contributors to ecosystem function.
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Affiliation(s)
- Amy Fisher
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia
| | - Daniel Wangpraseurt
- Marine Biological Section, University of Copenhagen, Copenhagen 1017, Denmark.,Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.,Scripps Institution of Oceanography, University of California, San Diego 92037, CA, USA
| | - Anthony W D Larkum
- Climate Change Cluster, University of Technology, Sydney 2007, Australia
| | - Michael Johnson
- Climate Change Cluster, University of Technology, Sydney 2007, Australia
| | - Michael Kühl
- Marine Biological Section, University of Copenhagen, Copenhagen 1017, Denmark.,Climate Change Cluster, University of Technology, Sydney 2007, Australia
| | - Min Chen
- School of Life and Environmental Sciences, University of Sydney, Sydney 2006, Australia
| | - Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia
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Effect of light wavelength on hot spring microbial mat biodiversity. PLoS One 2018; 13:e0191650. [PMID: 29381713 PMCID: PMC5790269 DOI: 10.1371/journal.pone.0191650] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/09/2018] [Indexed: 11/19/2022] Open
Abstract
Hot spring associated phototrophic microbial mats are purely microbial communities, in which phototrophic bacteria function as primary producers and thus shape the community. The microbial mats at Nakabusa hot springs in Japan harbor diverse photosynthetic bacteria, mainly Thermosynechococcus, Chloroflexus, and Roseiflexus, which use light of different wavelength for energy conversion. The aim of this study was to investigate the effect of the phototrophs on biodiversity and community composition in hot spring microbial mats. For this, we specifically activated the different phototrophs by irradiating the mats with different wavelengths in situ. We used 625, 730, and 890 nm wavelength LEDs alone or in combination and confirmed the hypothesized increase in relative abundance of different phototrophs by 16S rRNA gene sequencing. In addition to the increase of the targeted phototrophs, we studied the effect of the different treatments on chemotrophic members. The specific activation of Thermosynechococcus led to increased abundance of several other bacteria, whereas wavelengths specific to Chloroflexus and Roseiflexus induced a decrease in >50% of the community members as compared to the dark conditions. This suggests that the growth of Thermosynechococcus at the surface layer benefits many community members, whereas less benefit is obtained from an increase in filamentous anoxygenic phototrophs Chloroflexus and Roseiflexus. The increases in relative abundance of chemotrophs under different light conditions suggest a relationship between the two groups. Aerobic chemoheterotrophs such as Thermus sp. and Meiothermus sp. are thought to benefit from aerobic conditions and organic carbon in the form of photosynthates by Thermosynechococcus, while the oxidation of sulfide and production of elemental sulfur by filamentous anoxygenic phototrophs benefit the sulfur-disproportionating Caldimicrobium thiodismutans. In this study, we used an experimental approach under controlled environmental conditions for the analysis of natural microbial communities, which proved to be a powerful tool to study interspecies relationships in the microbiome.
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Freitas S, Silva H, Almeida J, Silva E. Hyperspectral Imaging for Real-Time Unmanned Aerial Vehicle Maritime Target Detection. J INTELL ROBOT SYST 2017. [DOI: 10.1007/s10846-017-0689-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Li T, Podola B, de Beer D, Melkonian M. A method to determine photosynthetic activity from oxygen microsensor data in biofilms subjected to evaporation. J Microbiol Methods 2015; 117:100-7. [DOI: 10.1016/j.mimet.2015.07.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 07/27/2015] [Accepted: 07/27/2015] [Indexed: 01/05/2023]
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Finke N, Hoehler TM, Polerecky L, Buehring B, Thamdrup B. Competition for inorganic carbon between oxygenic and anoxygenic phototrophs in a hypersaline microbial mat, Guerrero Negro, Mexico. Environ Microbiol 2013; 15:1532-50. [PMID: 23347091 DOI: 10.1111/1462-2920.12032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 10/24/2012] [Indexed: 11/28/2022]
Abstract
While most oxygenic phototrophs harvest light only in the visible range (400-700 nm, VIS), anoxygenic phototrophs can harvest near infrared light (> 700 nm, NIR). To study interactions between the photosynthetic guilds we used microsensors to measure oxygen and gross oxygenic photosynthesis (gOP) in a hypersaline microbial mat under full (VIS + NIR) and VIS illumination. Under normal dissolved inorganic carbon (DIC) concentrations (2 mM), volumetric rates of gOP were reduced up to 65% and areal rates by 16-31% at full compared with VIS illumination. This effect was enhanced (reduction up to 100% in volumetric, 50% in areal rates of gOP) when DIC was lowered to 1 mM, but diminished at 10 mM DIC or lowered pH. In conclusion, under full-light illumination anoxygenic phototrophs are able to reduce the activity of oxygenic phototrophs by efficiently competing for inorganic carbon within the highly oxygenated layer. Anoxygenic photosynthesis, calculated from the difference in gOP under full and VIS illumination, represented between 10% and 40% of the C-fixation. The DIC depletion in the euphotic zone as well as the significant C-fixation by anoxygenic phototrophs in the oxic layer influences the carbon isotopic composition of the mat, which needs to be taken into account when interpreting isotopic biosignals in geological records.
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Affiliation(s)
- Niko Finke
- Nordic Center for Earth Evolution, Institute of Biology, University of Southern Denmark, Odense, Denmark.
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Hubas C, Jesus B, Passarelli C, Jeanthon C. Tools providing new insight into coastal anoxygenic purple bacterial mats: review and perspectives. Res Microbiol 2011; 162:858-68. [DOI: 10.1016/j.resmic.2011.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 03/16/2011] [Indexed: 10/18/2022]
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Environmental Dynamics, Community Structure and Function in a Hypersaline Microbial Mat. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/978-90-481-3799-2_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Polerecky L, Bissett A, Al-Najjar M, Faerber P, Osmers H, Suci PA, Stoodley P, de Beer D. Modular spectral imaging system for discrimination of pigments in cells and microbial communities. Appl Environ Microbiol 2009; 75:758-71. [PMID: 19074609 PMCID: PMC2632136 DOI: 10.1128/aem.00819-08] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Accepted: 11/24/2008] [Indexed: 11/20/2022] Open
Abstract
Here we describe a spectral imaging system for minimally invasive identification, localization, and relative quantification of pigments in cells and microbial communities. The modularity of the system allows pigment detection on spatial scales ranging from the single-cell level to regions whose areas are several tens of square centimeters. For pigment identification in vivo absorption and/or autofluorescence spectra are used as the analytical signals. Along with the hardware, which is easy to transport and simple to assemble and allows rapid measurement, we describe newly developed software that allows highly sensitive and pigment-specific analyses of the hyperspectral data. We also propose and describe a number of applications of the system for microbial ecology, including identification of pigments in living cells and high-spatial-resolution imaging of pigments and the associated phototrophic groups in complex microbial communities, such as photosynthetic endolithic biofilms, microbial mats, and intertidal sediments. This system provides new possibilities for studying the role of spatial organization of microorganisms in the ecological functioning of complex benthic microbial communities or for noninvasively monitoring changes in the spatial organization and/or composition of a microbial community in response to changing environmental factors.
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Affiliation(s)
- Lubos Polerecky
- Max Planck Institute for Marine Microbiology, Bremen, Germany.
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