1
|
Nakashima T, Uetake J, Segawa T, Procházková L, Tsushima A, Takeuchi N. Spatial and Temporal Variations in Pigment and Species Compositions of Snow Algae on Mt. Tateyama in Toyama Prefecture, Japan. FRONTIERS IN PLANT SCIENCE 2021; 12:689119. [PMID: 34290725 PMCID: PMC8289405 DOI: 10.3389/fpls.2021.689119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/31/2021] [Indexed: 05/25/2023]
Abstract
Snow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016. High-performance liquid chromatographic analyses of the pigments extracted from the colored snow showed that their composition varied within the study area and were classified into four types: Type A (astaxanthin-monoester dominant), Type B (medium astaxanthin-monoester content), Type C (abundant primary carotenoids and free-astaxanthin), and Type D (abundant primary carotenoids and astaxanthin diesters). Types A and B were most commonly observed in the study area, whereas Types C and D appeared only at specific sites. Analysis of the 18S ribosomal RNA (18S rRNA) gene revealed six major amplicon sequence variants (ASVs) of snow algae, belonging to the Sanguina, Chloromonas, and Chlainomonas groups. The relative abundance of the algal ASVs showed that Sanguina was dominant (>48%) in both Types A and B, suggesting that the difference in astaxanthin abundance between the two types was caused by the production of pigments in the algal cells. The algal community structures of Types C and D differed from those of Types A and B, indicating that the primary carotenoids and astaxanthin diesters were derived from certain algal species in these types. Therefore, astaxanthin-rich Sanguina algae mostly induced the red snow that appeared widely in this alpine area; however, they were partially dominated by Chloromonas or Chlainomonas algae, causing different pigment compositions.
Collapse
Affiliation(s)
| | - Jun Uetake
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan
| | - Takahiro Segawa
- Center for Life Science Research, University of Yamanashi, Kofu, Japan
| | - Lenka Procházková
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Akane Tsushima
- Graduate School of Science, Chiba University, Chiba, Japan
| | | |
Collapse
|
2
|
Snow algae blooms are beneficial for microinvertebrates assemblages (Tardigrada and Rotifera) on seasonal snow patches in Japan. Sci Rep 2021; 11:5973. [PMID: 33727649 PMCID: PMC7971028 DOI: 10.1038/s41598-021-85462-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 03/01/2021] [Indexed: 11/08/2022] Open
Abstract
Although studies on snow algae and macroinvertebrates have been frequently conducted on snow patches, only few surveys have been focused on microinvertebrates which reach high biomass and play various trophic roles in other cold habitats. The aims of this study were (1) to search for microinvertebrates in seasonal surface snow patches located on the slope of Mt. Gassan, in northern Japan, and (2) to identify factors determining their distribution associated with snow algal blooms of various colorations (orange, green, and golden-brown) collected from the same sampling site over two seasons (2018, 2019). Microscopic observation revealed presence of two major groups of microinvertebrates: Tardigrada and Rotifera. They were concentrated in green snow colored by blooms of Chloromonas sp. in comparison to orange or golden-brown snow and only a few were found in white snow. Mean body length of tardigrades increased throughout the melt season, their intestine content was green and they laid eggs on colored snow. These results suggest that tardigrades preferentially grew and reproduced on green snow patches. Population densities of tardigrades, rotifers and concentration of chlorophyll a were significantly correlated. Our study indicates that green snow patches in temperate mountainous forests constitute important and unique low-temperature ecosystems for microinvertebrates. Snow covered by algae is an unrecognized novel habitats for tardigrades and rotifers.
Collapse
|
3
|
Del Arco A, Álvarez-Manzaneda I, Funes A, Pérez-Martínez C, de Vicente I. Assessing the toxic effects of magnetic particles used for lake restoration on phytoplankton: A community-based approach. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 207:111288. [PMID: 32949929 DOI: 10.1016/j.ecoenv.2020.111288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 06/11/2023]
Abstract
Inactivation by adding different phosphorus (P) adsorbents is one of the most frequently used methods for combating inland water eutrophication. The aim of this work was to assess the toxic effects of novel P adsorbents (magnetic particles, MPs) on the phytoplankton community. An outdoor microcosm experiment, containing lake water and surface sediment from a hypertrophic Mediterranean lake, was carried out following a factorial design (n = 5) with three different treatments: control (C), where no MPs were added; Treatment-Water (T-W) and Treatment-Sediment (T-S). In T-W and T-S treatments, MPs were added on the surface water layer and on the sediment, respectively, to obtain a final concentration of 1.4 g MP L-1. This concentration was based on both the sedimentary mobile P concentration of the study site and the maximum P adsorption capacity of the MPs, obtained from the literature. After 24 h of contact time, the MPs were removed using a magnetic rake. Physicochemical measurements and biological samples were taken after 24 h of exposure to the MPs and at different time points after such exposure (day 2, 7, 21, 35 and 70). Changes in phytoplankton community such as abundance (biovolume and Chla), species composition and taxonomic groups were assessed, as well as changes in the Shannon-Wiener diversity index. Additionally, the eutrophic metric Algae Group Index (AGI), one of the metrics proposed in the Water Framework Directive, was also calculated. Our results indicate that there is no strong evidence to infer that MPs caused an effect on the phytoplankton community, since no significant differences (GLM test; p > 0.05) were found between controls and treatments in any of the studied variables (phytoplankton taxonomic groups, AGI, Chla concentration, biovolume, diversity and community responses). Accordingly, MPs did not cause any toxic effects on the phytoplankton community of the lake, encouraging the use of MPs in a future whole-lake restoration strategy. However, if the final goal of the restoration plan is to combat nuisance cyanobacteria blooms, higher initial MPs doses or repeated MPs applications are required to achieve a reduction in P concentrations below biological thresholds in order to prevent algal blooms.
Collapse
Affiliation(s)
- Ana Del Arco
- Instituto Del Agua, Universidad de Granada, 18071, Spain.
| | | | - Ana Funes
- Instituto Del Agua, Universidad de Granada, 18071, Spain
| | - Carmen Pérez-Martínez
- Instituto Del Agua, Universidad de Granada, 18071, Spain; Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Spain
| | - Inmaculada de Vicente
- Instituto Del Agua, Universidad de Granada, 18071, Spain; Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, 18071, Spain
| |
Collapse
|
4
|
Luo W, Ding H, Li H, Ji Z, Huang K, Zhao W, Yu Y, Zeng Y. Molecular diversity of the microbial community in coloured snow from the Fildes Peninsula (King George Island, Maritime Antarctica). Polar Biol 2020. [DOI: 10.1007/s00300-020-02716-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
5
|
Lassalle G, Fabre S, Credoz A, Dubucq D, Elger A. Monitoring oil contamination in vegetated areas with optical remote sensing: A comprehensive review. JOURNAL OF HAZARDOUS MATERIALS 2020; 393:122427. [PMID: 32155523 DOI: 10.1016/j.jhazmat.2020.122427] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 02/11/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
The monitoring of soil contamination deriving from oil and gas industry remains difficult in vegetated areas. Over the last decade, optical remote sensing has proved helpful for this purpose. By tracking alterations in vegetation biochemistry through its optical properties, multi- and hyperspectral remote sensing allow detecting and quantifying crude oil and petroleum products leaked following accidental leakages or bad cessation practices. Recent advances in this field have led to the development of various methods that can be applied either in the field using portable spectroradiometers or at large scale on airborne and satellite images. Experiments carried out under controlled conditions have largely contributed to identifying the most important factors influencing the detection of oil (plant species, mixture composition, etc.). In a perspective of operational use, an important effort is still required to make optical remote sensing a reliable tool for oil and gas companies. The current methods used on imagery should extend their scope to a wide range of contexts and their application to upcoming satellite-embedded hyperspectral sensors should be considered in future studies.
Collapse
Affiliation(s)
- Guillaume Lassalle
- Office National d'Études et de Recherches Aérospatiales (ONERA), Toulouse, France; TOTAL S.A., Pôle d'Études et de Recherches de Lacq, Lacq, France; EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| | - Sophie Fabre
- Office National d'Études et de Recherches Aérospatiales (ONERA), Toulouse, France
| | - Anthony Credoz
- TOTAL S.A., Pôle d'Études et de Recherches de Lacq, Lacq, France
| | - Dominique Dubucq
- TOTAL S.A., Centre Scientifique et Technique Jean-Féger, Pau, France
| | - Arnaud Elger
- EcoLab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France
| |
Collapse
|
6
|
Krug L, Erlacher A, Markut K, Berg G, Cernava T. The microbiome of alpine snow algae shows a specific inter-kingdom connectivity and algae-bacteria interactions with supportive capacities. ISME JOURNAL 2020; 14:2197-2210. [PMID: 32424246 PMCID: PMC7608445 DOI: 10.1038/s41396-020-0677-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 04/25/2020] [Accepted: 05/01/2020] [Indexed: 12/15/2022]
Abstract
Mutualistic interactions within microbial assemblages provide a survival strategy under extreme conditions; however, little is known about the complexity of interaction networks in multipartite, free-living communities. In the present study, the interplay within algae-dominated microbial communities exposed to harsh environmental influences in the Austrian Alps was assessed in order to reveal the interconnectivity of eukaryotic and prokaryotic inhabitants. All analyzed snowfields harbored distinct microbial communities. Network analyses revealed that mutual exclusion prevailed among microalgae in the alpine environment, while bacteria were mainly positively embedded in the interaction networks. Especially members of Proteobacteria, with a high prevalence of Oxalobacteraceae, Pseudomonadaceae, and Sphingomonadaceae showed genus-specific co-occurrences with distinct microalgae. Co-cultivation experiments with algal and bacterial isolates confirmed beneficial interactions that were predicted based on the bioinformatic analyses; they resulted in up to 2.6-fold more biomass for the industrially relevant microalga Chlorella vulgaris, and up to 4.6-fold increase in biomass for the cryophilic Chloromonas typhlos. Our findings support the initial hypothesis that microbial communities exposed to adverse environmental conditions in alpine systems harbor inter-kingdom supportive capacities. The insights into mutualistic inter-kingdom interactions and the ecology of microalgae within complex microbial communities provide explanations for the prevalence and resilience of such assemblages in alpine environments.
Collapse
Affiliation(s)
- Lisa Krug
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria.,ACIB GmbH, Petersgasse 14, 8010, Graz, Austria
| | - Armin Erlacher
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria
| | - Katharina Markut
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria
| | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria
| | - Tomislav Cernava
- Institute of Environmental Biotechnology, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria.
| |
Collapse
|
7
|
Hoham RW, Remias D. Snow and Glacial Algae: A Review 1. JOURNAL OF PHYCOLOGY 2020; 56:264-282. [PMID: 31825096 PMCID: PMC7232433 DOI: 10.1111/jpy.12952] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/20/2019] [Indexed: 05/03/2023]
Abstract
Snow or glacial algae are found on all continents, and most species are in the Chlamydomonadales (Chlorophyta) and Zygnematales (Streptophyta). Other algal groups include euglenoids, cryptomonads, chrysophytes, dinoflagellates, and cyanobacteria. They may live under extreme conditions of temperatures near 0°C, high irradiance levels in open exposures, low irradiance levels under tree canopies or deep in snow, acidic pH, low conductivity, and desiccation after snow melt. These primary producers may color snow green, golden-brown, red, pink, orange, or purple-grey, and they are part of communities that include other eukaryotes, bacteria, archaea, viruses, and fungi. They are an important component of the global biosphere and carbon and water cycles. Life cycles in the Chlamydomonas-Chloromonas-Chlainomonas complex include migration of flagellates in liquid water and formation of resistant cysts, many of which were identified previously as other algae. Species differentiation has been updated through the use of metagenomics, lipidomics, high-throughput sequencing (HTS), multi-gene analysis, and ITS. Secondary metabolites (astaxanthin in snow algae and purpurogallin in glacial algae) protect chloroplasts and nuclei from damaging PAR and UV, and ice binding proteins (IBPs) and polyunsaturated fatty acids (PUFAs) reduce cell damage in subfreezing temperatures. Molecular phylogenies reveal that snow algae in the Chlamydomonas-Chloromonas complex have invaded the snow habitat at least twice, and some species are polyphyletic. Snow and glacial algae reduce albedo, accelerate the melt of snowpacks and glaciers, and are used to monitor climate change. Selected strains of these algae have potential for producing food or fuel products.
Collapse
Affiliation(s)
- Ronald W. Hoham
- Department of BiologyColgate UniversityHamiltonNew York13346USA
| | - Daniel Remias
- School of EngineeringUniversity of Applied Sciences Upper AustriaWels4600Austria
| |
Collapse
|
8
|
Remias D, Procházková L, Nedbalová L, Andersen RA, Valentin K. Two New Kremastochrysopsis species, K. austriaca sp. nov. and K. americana sp. nov. (Chrysophyceae) 1. JOURNAL OF PHYCOLOGY 2020; 56:135-145. [PMID: 31639884 PMCID: PMC7054049 DOI: 10.1111/jpy.12937] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 09/10/2019] [Indexed: 05/20/2023]
Abstract
Melting summer snow in the Austrian Alps exhibited a yellowish bloom that was mainly comprised of an unidentified unicellular chrysophyte. Molecular data (18S rRNA and rbcL genes) showed a close relationship to published sequences from an American pond alga formerly identified as Kremastochrysis sp. The genera Kremastochrysis and Kremastochrysopsis are morphologically distinguished by the number of flagella observed with the light microscope, and therefore we assigned the Austrian snow alga and an American pond alga to the genus Kremastochrysopsis. Transmission and scanning electron microscopy revealed that swimming cells had two flagella oriented in opposite directions, typical for the Hibberdiales. Molecular phylogenetic analyses showed that both new species were closely related to Hibberdia. Kremastochrysopsis ocellata, the type species and only known species, has two chloroplasts per cell and the zoospores have red eyespots. Our two organisms had only a single chloroplast and no zoospore eyespot, but their gene sequences differed substantially. Therefore, we described two new species, Kremastochrysopsis austriaca sp. nov and Kremstochrysopsis americana sp. nov. When grown in culture, both taxa showed a characteristic hyponeustonic growth (hanging below the water surface), whereas older immotile cells grew at the bottom of the culture vessel. Ecologically, Kremastochrysopsis austriaca sp. nov., which caused snow discolorations, had no close phylogenetic relationships to other psychrophilic chrysophytes, for example, Chromulina chionophilia, Hydrurus sp., and Ochromonas-like flagellates.
Collapse
Affiliation(s)
- Daniel Remias
- School of EngineeringUniversity of Applied Sciences Upper Austria4600WelsAustria
| | - Lenka Procházková
- Department of EcologyFaculty of ScienceCharles University12844PragueCzech Republic
| | - Linda Nedbalová
- Department of EcologyFaculty of ScienceCharles University12844PragueCzech Republic
| | - Robert A. Andersen
- Friday Harbor LaboratoriesUniversity of WashingtonFriday HarborWashingtonDC98250USA
| | | |
Collapse
|
9
|
Wilken S, Choi CJ, Worden AZ. Contrasting Mixotrophic Lifestyles Reveal Different Ecological Niches in Two Closely Related Marine Protists. JOURNAL OF PHYCOLOGY 2020; 56:52-67. [PMID: 31529498 PMCID: PMC7065223 DOI: 10.1111/jpy.12920] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/13/2019] [Indexed: 05/13/2023]
Abstract
Many marine microbial eukaryotes combine photosynthetic with phagotrophic nutrition, but incomplete understanding of such mixotrophic protists, their functional diversity, and underlying physiological mechanisms limits the assessment and modeling of their roles in present and future ocean ecosystems. We developed an experimental system to study responses of mixotrophic protists to availability of living prey and light, and used it to characterize contrasting physiological strategies in two stramenopiles in the genus Ochromonas. We show that oceanic isolate CCMP1393 is an obligate mixotroph, requiring both light and prey as complementary resources. Interdependence of photosynthesis and heterotrophy in CCMP1393 comprises a significant role of mitochondrial respiration in photosynthetic electron transport. In contrast, coastal isolate CCMP2951 is a facultative mixotroph that can substitute photosynthesis by phagotrophy and hence grow purely heterotrophically in darkness. In contrast to CCMP1393, CCMP2951 also exhibits a marked photoprotection response that integrates non-photochemical quenching and mitochondrial respiration as electron sink for photosynthetically produced reducing equivalents. Facultative mixotrophs similar to CCMP2951 might be well adapted to variable environments, while obligate mixotrophs similar to CCMP1393 appear capable of resource efficient growth in oligotrophic ocean environments. Thus, the responses of these phylogenetically close protists to the availability of different resources reveals niche differentiation that influences impacts in food webs and leads to opposing carbon cycle roles.
Collapse
Affiliation(s)
- Susanne Wilken
- Monterey Bay Aquarium Research Institute7700 Sandholdt RoadMoss LandingCalifornia95039USA
- Department of Freshwater and Marine EcologyInstitute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Chang Jae Choi
- Monterey Bay Aquarium Research Institute7700 Sandholdt RoadMoss LandingCalifornia95039USA
- Ocean EcoSystems Biology UnitGEOMAR Helmholtz Centre for Ocean ResearchDüsternbrooker Weg 20Kiel24105Germany
| | - Alexandra Z. Worden
- Monterey Bay Aquarium Research Institute7700 Sandholdt RoadMoss LandingCalifornia95039USA
- Ocean EcoSystems Biology UnitGEOMAR Helmholtz Centre for Ocean ResearchDüsternbrooker Weg 20Kiel24105Germany
| |
Collapse
|
10
|
Soto DF, Fuentes R, Huovinen P, Gómez I. Microbial composition and photosynthesis in Antarctic snow algae communities: Integrating metabarcoding and pulse amplitude modulation fluorometry. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
11
|
Goss R, Lepetit B. Biodiversity of NPQ. JOURNAL OF PLANT PHYSIOLOGY 2015; 172:13-32. [PMID: 24854581 DOI: 10.1016/j.jplph.2014.03.004] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/10/2014] [Accepted: 03/11/2014] [Indexed: 05/21/2023]
Abstract
In their natural environment plants and algae are exposed to rapidly changing light conditions and light intensities. Illumination with high light intensities has the potential to overexcite the photosynthetic pigments and the electron transport chain and thus induce the production of toxic reactive oxygen species (ROS). To prevent damage by the action of ROS, plants and algae have developed a multitude of photoprotection mechanisms. One of the most important protection mechanisms is the dissipation of excessive excitation energy as heat in the light-harvesting complexes of the photosystems. This process requires a structural change of the photosynthetic antenna complexes that are normally optimized with regard to efficient light-harvesting. Enhanced heat dissipation in the antenna systems is accompanied by a strong quenching of the chlorophyll a fluorescence and has thus been termed non-photochemical quenching of chlorophyll a fluorescence, NPQ. The general importance of NPQ for the photoprotection of plants and algae is documented by its wide distribution in the plant kingdom. In the present review we will summarize the present day knowledge about NPQ in higher plants and different algal groups with a special focus on the molecular mechanisms that lead to the structural rearrangements of the antenna complexes and enhanced heat dissipation. We will present the newest models for NPQ in higher plants and diatoms and will compare the features of NPQ in different algae with those of NPQ in higher plants. In addition, we will briefly address evolutionary aspects of NPQ, i.e. how the requirements of NPQ have changed during the transition of plants from the aquatic habitat to the land environment. We will conclude with a presentation of open questions regarding the mechanistic basis of NPQ and suggestions for future experiments that may serve to obtain this missing information.
Collapse
Affiliation(s)
- Reimund Goss
- Institut für Biologie, Universität Leipzig, Johannisallee 21-23, D-04103 Leipzig, Germany.
| | - Bernard Lepetit
- Institut für Biologie, Universität Konstanz, Universitätsstrasse 10, D-78457 Konstanz, Germany
| |
Collapse
|
12
|
Uetake J, Tanaka S, Hara K, Tanabe Y, Samyn D, Motoyama H, Imura S, Kohshima S. Novel biogenic aggregation of moss gemmae on a disappearing African glacier. PLoS One 2014; 9:e112510. [PMID: 25401789 PMCID: PMC4234412 DOI: 10.1371/journal.pone.0112510] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 10/18/2014] [Indexed: 11/18/2022] Open
Abstract
Tropical regions are not well represented in glacier biology, yet many tropical glaciers are under threat of disappearance due to climate change. Here we report a novel biogenic aggregation at the terminus of a glacier in the Rwenzori Mountains, Uganda. The material was formed by uniseriate protonemal moss gemmae and protonema. Molecular analysis of five genetic markers determined the taxon as Ceratodon purpureus, a cosmopolitan species that is widespread in tropical to polar region. Given optimal growing temperatures of isolate is 20-30 °C, the cold glacier surface might seem unsuitable for this species. However, the cluster of protonema growth reached approximately 10 °C in daytime, suggesting that diurnal increase in temperature may contribute to the moss's ability to inhabit the glacier surface. The aggregation is also a habitat for microorganisms, and the disappearance of this glacier will lead to the loss of this unique ecosystem.
Collapse
Affiliation(s)
- Jun Uetake
- Transdisciplinary Research Integration Center, Minato-ku, Tokyo, Japan
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
- * E-mail:
| | - Sota Tanaka
- Faculty of Science, Chiba University, Chiba, Chiba, Japan
| | - Kosuke Hara
- Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Yukiko Tanabe
- Institute for Advanced Study, Waseda University, Shinjuku-ku, Tokyo, Japan
| | - Denis Samyn
- Department of Mechanical Engineering, Nagaoka University of Technology, Nagaoka, Nigata, Japan
| | | | - Satoshi Imura
- Faculty of Science, Chiba University, Chiba, Chiba, Japan
| | - Shiro Kohshima
- Wildlife Research Center, Kyoto University, Kyoto, Kyoto, Japan
| |
Collapse
|
13
|
Stamenković M, Bischof K, Hanelt D. Xanthophyll cycle pool size and composition in several Cosmarium strains (Zygnematophyceae, Streptophyta) are related to their geographic distribution patterns. Protist 2013; 165:14-30. [PMID: 24334196 DOI: 10.1016/j.protis.2013.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 10/20/2013] [Accepted: 10/27/2013] [Indexed: 12/20/2022]
Abstract
The photosynthetic behaviour and composition of photosynthetic pigments of four Cosmarium strains collected from different geographic areas were examined under moderate and photoinhibitory white light by means of PAM fluorometry and high-performance liquid chromatography. Generally, all of the Cosmarium strains displayed the photosynthetic performance and the composition of xanthophyll cycle pigments corresponding to that of high-light adapted plants and algae, when grown under the standard laboratory conditions. However, photoinhibitory treatments provoked several strain- and species-specific characteristics despite the long-term cultivation in laboratory conditions. The typical arctic taxon, C. crenatum var. boldtianum, displayed an incomplete violaxanthin cycle yielding an accumulation of antheraxanthin during high light stress, which is considered as an adaptation to occasional high irradiances in the polar zone due to the albedo. So far, the violaxanthin/antheraxanthin turnover was known only in some prasinophycean algae. Antheraxanthin actively participated in the heat dissipation from PSII centres in C. crenatum, as concluded from a significant positive correlation between non-photochemical quenching (NPQ) and the quantity of antheraxanthin. In contrast, all the other Cosmarium strains displayed a complete violaxanthin de-epoxidase action during the high light treatments, as judged from the relatively high production of zeaxanthin which participated in thermal dissipation of excess energy.
Collapse
Affiliation(s)
- Marija Stamenković
- Biozentrum Klein Flottbek, Universität Hamburg, Ohnhorst Str. 18, 22609 Hamburg, Germany.
| | - Kai Bischof
- Department of Marine Botany, Universität Bremen, Leobener Str. NW2, 28359 Bremen, Germany
| | - Dieter Hanelt
- Biozentrum Klein Flottbek, Universität Hamburg, Ohnhorst Str. 18, 22609 Hamburg, Germany
| |
Collapse
|
14
|
Possible ecological implications of floating microbial assemblages lifted from the lakebed on an Antarctic lake. Ecol Res 2012. [DOI: 10.1007/s11284-011-0907-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|