Vertical distribution of planktonic autotrophic thiobacilli and dark CO2 fixation rates in lakes with oxygen–sulfide interfaces

Casamayor, Emilio O.

doi:10.3354/ame01399

Cited by 18 publications

(18 citation statements)

References 48 publications

(63 reference statements)

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“…Thus, essentially all microorganisms can assimilate CO 2 in any step of their metabolism, but the maximal activity should be expected at the oxic-anoxic interface where the true specialists may develop. However, as a whole, we did not find any significant correlation between these rates and either nutrient distribution or microbial community composition in the study lakes and in other similar lakes reported elsewhere (García-Cantizano et al 2005, Casamayor 2010). This may indicate that different physiologies and ecologies may simultaneously contribute in situ to the dark carbon fixation activity of these ecosystems.…”

Section: Discussioncontrasting

confidence: 39%

Contribution of deep dark fixation processes to overall CO2 incorporation and large vertical changes of microbial populations in stratified karstic lakes

et al. 2011

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We carried out a detailed study in five stratified lakes in the karstic regions of NE Spain along a redox gradient combining vertical profiles of inorganic carbon dioxide fixation and analysis of microbial (bacteria and archaea) community composition determined by 16S rRNA gene fingerprinting (DGGE), microscopic counts, and pigment analysis. High rates of non-photosynthetic (i.e., ''dark'') inorganic carbon incorporation were detected mostly at deeper layers after short-term in situ incubations at noon. Significant contribution of dark CO 2 incorporation was observed at the whole lake level for the single time sampling, ranging between 4 and 19% of total carbon fixation measured, and up to 31% in the case of a meromictic basin. Good agreement was found between vertical patterns in redox conditions and the different microbial diversity descriptors (DGGE band sequencing, microscopic analysis, and pigment data), showing large vertical changes in microbial community composition covering a wide range of phylogenetic diversity. Cyanobacteria, Alpha and Beta-Proteobacteria, Actinobacteria, Flavobacteria and Flectobacillaceae were the most frequently recovered groups in the DGGE from oxygenated water masses. In anoxic waters, we found Beta-Proteobacteria mostly of the Rhodoferax group, Gamma-Proteobacteria (Chromatiaceae), Delta-Proteobacteria related to different sulfate reducing bacteria, Chlorobiaceae, and anaerobic Bacteroidetes spread among the Bacteroidales, Flavobacteriales and Saprospiraceae. However, as a whole, we did not find any significant correlation between dark fixation rates and either nutrient distribution and microbial community composition in the study lakes. All of this suggests that (1) different physiologies and ecologies are simultaneously contributing to the process (2) more sensitive methods are needed and more specific compounds measured and (3) some of the non-specialist microbial populations detected may carry out carbon dioxide assimilation in the dark under in situ conditions.

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Section: Discussioncontrasting

confidence: 39%

Contribution of deep dark fixation processes to overall CO2 incorporation and large vertical changes of microbial populations in stratified karstic lakes

et al. 2011

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“…Sulfurimonas (Grote et al , 2007, 2008)], and the aerobic sulfur‐oxidizing bacteria [e.g. Thiobacilli (Casamayor, 2010)]. However, the capability of lacustrine archaea other than ammonia oxidizers to incorporate CO 2 in the dark has not been assessed in aquatic environments with well‐defined oxic/anoxic interfaces.…”

Section: Discussionmentioning

confidence: 99%

“…In some of these habitats, the values of dark fixation rates integrated for the entire water column were equivalent to those calculated for light‐driven processes, indicating that dark assimilation could not be easily disregarded. Besides, the complexity of the microbial assemblages thriving in environments with oxic/anoxic interfaces and the availability of different energy sources and electron donors favor the presence of a large diversity of microorganisms involved in chemoautotrophic activities (Casamayor, 2010).…”

Section: Introductionmentioning

confidence: 99%

Active bacteria and archaea cells fixing bicarbonate in the dark along the water column of a stratified eutrophic lagoon

Llirós

Alonso‐Sáez

Gich

et al. 2011

FEMS Microbiology Ecology

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We studied the carbon dioxide fixation activity in a stratified hypereutrophic karstic lagoon using a combination of fingerprinting techniques targeting bacterial and archaeal 16S rRNA genes, functional gene cloning [the acetyl-CoA carboxylase (accC)], and isotopic labelling ((14)C-bicarbonate) coupled to single-cell analyses [microautoradiography combined with catalyzed reported deposition-FISH (MAR-CARD-FISH)]. The microbial planktonic community was dominated by bacteria with maximal abundances of archaea just below the oxic/anoxic transition zone (7% of total cells). In situ incubations with radiolabelled bicarbonate showed maximal photoassimilation activity in the oxic epilimnion, whereas dark CO(2) fixation was consistently observed throughout the water column, with a maximum at the oxic/anoxic interface (8.6 mg C m(-3) h(-1)). The contributions of light and dark carbon fixation activities in the whole water column were 69% and 31% of the total C incorporated, respectively. MAR-CARD-FISH incubations corroborated these results and revealed that the highest fraction of bacterial and archaeal cells actively uptaking bicarbonate in the light was found at the surface. The bacterial community was mainly composed of green sulfur bacteria (Chlorobi) and members of the Betaproteobacteria and the Bacteroidetes. The archaeal assemblage was composed of phylotypes of the Miscellaneous Crenarchaeotic Group and a few methanogens. Clone libraries of the accC gene showed an absolute dominance of bacterial carboxylases. Our results suggest that the dark carbon fixation activity measured was mainly related to CO(2) incorporation by heterotrophs rather than to the activity of true chemoautotrophs.

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“…4 and 6). Despite the apparent vertical and seasonal pattern, most previous studies found weak or no correlation between chemoautotrophy and geochemical variables presumably due to the coexistence of a diverse assemblage of physiological and ecological types of chemoautotrophs (Casamayor, 2010;Casamayor et al, 2012). However, we found significant models with a gradient of some geochemical variables, including density, DO, DS, DFe, and Table 1 Correlation matrix of biogeochemical values at different depths (lower left) and gradients across neighboring depths (upper right) during the temporal and transect survey (n ¼ 88).…”

Section: Chemoautotrophymentioning

confidence: 91%

“…One of best-studied examples of microbial diversity are active chemoautotrophic and anoxygenic photoautotrophic processes attributed to the simultaneous presence of various oxidized and reduced compounds. The vertical distribution of the microbes is strongly related to the vertical structure of oxic/anoxic or oxic/sulfidic interfaces (Sorokin et al, 1995;Casamayor, 2010;Casamayor et al, 2012). In some ecosystems where photosynthetic production is restricted to upper mixed layers, chemoautotrophic production can support a deep secondary microbial food web (Ho et al, 2004;Alonso-S aez et al, 2010;Swan et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Elevated microbial CO2 production and fixation in the oxic/anoxic interface of estuarine water columns during seasonal anoxia

Lee

Owens

Crump

et al. 2015

Estuarine, Coastal and Shelf Science

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a b s t r a c tGradients of dissolved oxygen concentrations in stratified estuarine water columns directly influence microbial composition and metabolic pathways, resulting in vertical and axial chemical gradients of redox-active species. Understanding such microbial responses to changing geochemical conditions and elucidating the diversity of microbially-mediated processes are needed to comprehensively identify ecosystem functions. We tested the hypothesis that microbial metabolic processes in the vicinity of the oxic/anoxic interface in Chesapeake Bay would be elevated due to the coincidence of oxidized and reduced compounds. We measured rates of microbial redox processes associated with carbon cycles and quantified geochemical constituents. The transition from oxic to anoxic to oxic conditions was correlated with the pattern of dissolved nitrogen species, with the most reducing conditions comprising the highest concentrations of dissolved chemical compounds. The vertical distribution of community respiration was measured with changes in dissolved inorganic carbon concentrations and was related to water column stratification, with the highest median and variability (1.2 ± 1.4 mmol L À1 h À1 ) in the most stratified conditions. Rates of CO 2 fixation under dark conditions, a measure of chemoautotrophy, were elevated at the base of oxyclines and significantly correlated with a gradient of density and some reduced compounds. Although vertical interpolation must be made with caution due to high vertical variability, chemoautotrophic production averaged 0.5 mmol m À2 h À1 from May to August and added 5.8% to autochthonous organic carbon production in the mesohaline Chesapeake Bay. Overall, our results suggest that anaerobic community metabolism and chemoautotrophy in the oxic/anoxic interface exert a small impact on estuarine carbon cycles.

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Vertical distribution of planktonic autotrophic thiobacilli and dark CO2 fixation rates in lakes with oxygen–sulfide interfaces

Cited by 18 publications

References 48 publications

Contribution of deep dark fixation processes to overall CO2 incorporation and large vertical changes of microbial populations in stratified karstic lakes

Contribution of deep dark fixation processes to overall CO2 incorporation and large vertical changes of microbial populations in stratified karstic lakes

Active bacteria and archaea cells fixing bicarbonate in the dark along the water column of a stratified eutrophic lagoon

Elevated microbial CO2 production and fixation in the oxic/anoxic interface of estuarine water columns during seasonal anoxia

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