scholarly journals Anoxygenic photo- and chemosynthesis of phototrophic sulfur bacteria from an alpine meromictic lake

2021 ◽  
Author(s):  
Francesco Di Nezio ◽  
Clarisse Beney ◽  
Samuele Roman ◽  
Francesco Danza ◽  
Antoine Buetti-Dinh ◽  
...  
Keyword(s):  
Carbon Fixation ◽  
Meromictic Lake ◽  
Purple Sulfur Bacterium ◽  
Phototrophic Sulfur Bacteria ◽  
Anaerobic Microorganisms ◽  
Sulfur Bacteria ◽  
Pure Cultures ◽  
Chlorobium Phaeobacteroides ◽  
Anoxic Environment ◽  
Dark Carbon Fixation

Abstract Meromictic lakes are interesting ecosystems to study anaerobic microorganisms due their permanent stratification allowing the formation of a stable anoxic environment. The crenogenic meromictic Lake Cadagno harbors an important community of anoxygenic phototrophic sulfur bacteria responsible for almost half of its total productivity. Besides their ability to fix CO2 through photosynthesis, these microorganisms also showed high rates of dark carbon fixation via chemosyntesis. Here, we grew in pure cultures three populations of anoxygenic phototrophic sulfur bacteria previously isolated from the lake, accounting for 72.8% of the total microbial community, and exibiting different phenotypes: 1) the motile, large-celled purple sulfur bacterium (PSB) Chromatium okenii, 2) the small-celled PSB Thiodictyon syntrophicum, and 3) the green sulfur bacterium (GSB) Chlorobium phaeobacteroides. We measured their ability to fix CO2 through photo- and chemo-synthesis, both in situ in the lake and in laboratory under different incubation conditions. We also evaluated the efficiency and velocity of H2S photo-oxidation, an important reaction in the anoxygenic photosynthesis process. Our results confirm that phototrophic sulfur bacteria strongly fix CO2 in the presence of light and that oxygen increases chemosynthesis at night, in laboratory conditions. Moreover, substancial differences were displayed between the three selected populations in terms of activity and abundance.

scholarly journals In situabundance and carbon fixation activity of distinct anoxygenic phototrophs in the stratified seawater lake Rogoznica

2019 ◽  
Author(s):  
Petra Pjevac ◽  
Stefan Dyksma ◽  
Tobias Goldhammer ◽  
Izabela Mujakić ◽  
Michal Koblížek ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Carbon Fixation ◽  
Green Sulfur Bacteria ◽  
Purple Sulfur Bacteria ◽  
Purple Sulfur Bacterium ◽  
Anoxygenic Phototrophs ◽  
Flow Cytometric ◽  
Sulfur Bacteria ◽  
Chlorobium Phaeobacteroides ◽  
Green Sulfur

AbstractSulfide-driven anoxygenic photosynthesis is an ancient microbial metabolism that contributes significantly to inorganic carbon fixation in stratified, sulfidic water bodies. Methods commonly applied to quantify inorganic carbon fixation by anoxygenic phototrophs, however, cannot resolve the contributions of distinct microbial populations to the overall process. We implemented a straightforward workflow, consisting of radioisotope labeling and flow cytometric cell sorting based on the distinct autofluorescence of bacterial photo pigments, to discriminate and quantify contributions of co-occurring anoxygenic phototrophic populations toin situinorganic carbon fixation in environmental samples. This allowed us to assign 89.3 ±7.6% of daytime inorganic carbon fixation by anoxygenic phototrophs in Lake Rogoznica (Croatia) to an abundant chemocline-dwelling population of green sulfur bacteria (dominated byChlorobium phaeobacteroides), whereas the co-occurring purple sulfur bacteria (Halochromatiumsp.) contributed only 1.8 ±1.4%. Furthermore, we obtained two metagenome assembled genomes of green sulfur bacteria and one of a purple sulfur bacterium which provides the first genomic insights into the genusHalochromatium, confirming its high metabolic flexibility and physiological potential for mixo-and heterotrophic growth.

scholarly journals Anoxygenic Photosynthesis and Dark Carbon Metabolism under micro-oxic conditions in the Purple Sulfur Bacterium “Thiodictyon syntrophicum” nov. strain Cad16T

2018 ◽  
Author(s):  
Samuel M Luedin ◽  
Nicola Storelli ◽  
Francesco Danza ◽  
Samuele Roman ◽  
Matthias Wittwer ◽  
...  
Keyword(s):  
Carbon Fixation ◽  
Light Availability ◽  
Swiss Alps ◽  
Purple Sulfur Bacterium ◽  
Metabolic Functions ◽  
Pure Cultures ◽  
Dialysis Bag ◽  
Dark Carbon Fixation ◽  
Oxidative Respiration ◽  
Relative Change

1.ABSTRACTThe microbial ecosystem of the meromictic Lake Cadagno (Ticino, Swiss Alps) has been studied intensively to understand metabolic functions driven by the highly abundant anoxygenic phototrophic sulfur bacteria of the families Chromatiaceae and Chlorobiaceae. It was found that the sequenced isolate “Thiodictyon syntrophicum” nov. sp. str. Cad16T, belonging to the Chromatiaceae, may fix 26% of all bulk inorganic carbon in the chemocline at day and night. With this study, we elucidated the mode of dark carbon fixation of str. Cad16Twith a combination of long-term monitoring of key physicochemical parameters with CTD,14C-incorporation experiments and quantitative proteomics ofin situdialysis bag incubations of pure cultures. Regular vertical CTD profiling during the study period in summer 2017 revealed that the chemocline sank from 12 to 14 m which was accompanied by a bloom of cyanobacteria and the subsequent oxygenation of the deeper water column. Sampling was performed both day and night in September. While CO2assimilation rates were higher during the light period, the relative change in the proteome (663 quantified proteins) was only 1% of all CDS encoded in str. Cad16T. Oxidative respiration was thereby upregulated at light, whereas stress-related mechanisms prevailed during the night. These results indicate that the low light availability due to high cell concentrations and the oxygenation of the chemocline induced a mixotrophic growth in str. Cad16T.The complete proteome data have been deposited to the ProteomeXchange with identifier PXD010641.

scholarly journals Dynamic cellular complexity of anoxygenic phototrophic sulfur bacteria in the chemocline of meromictic Lake Cadagno

PLoS ONE ◽  
2017 ◽  
Vol 12 (12) ◽  
pp. e0189510 ◽  
Author(s):  
Francesco Danza ◽  
Nicola Storelli ◽  
Samuele Roman ◽  
Samuel Lüdin ◽  
Mauro Tonolla
Keyword(s):  
Meromictic Lake ◽  
Phototrophic Sulfur Bacteria ◽  
Sulfur Bacteria

scholarly journals Long-Term Population Dynamics of Phototrophic Sulfur Bacteria in the Chemocline of Lake Cadagno, Switzerland

2005 ◽  
Vol 71 (7) ◽  
pp. 3544-3550 ◽  
Author(s):  
Mauro Tonolla ◽  
Raffaele Peduzzi ◽  
Dittmar Hahn
Keyword(s):  
Major Change ◽  
Green Sulfur Bacteria ◽  
Purple Sulfur Bacteria ◽  
Phototrophic Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Large Fluctuations ◽  
Order Of Magnitude ◽  
Chlorobium Phaeobacteroides ◽  
Green Sulfur ◽  
Different Populations

ABSTRACT Population analyses in water samples obtained from the chemocline of crenogenic, meromictic Lake Cadagno, Switzerland, in October for the years 1994 to 2003 were studied using in situ hybridization with specific probes. During this 10-year period, large shifts in abundance between purple and green sulfur bacteria and among different populations were obtained. Purple sulfur bacteria were the numerically most prominent phototrophic sulfur bacteria in samples obtained from 1994 to 2001, when they represented between 70 and 95% of the phototrophic sulfur bacteria. All populations of purple sulfur bacteria showed large fluctuations in time with populations belonging to the genus Lamprocystis being numerically much more important than those of the genera Chromatium and Thiocystis. Green sulfur bacteria were initially represented by Chlorobium phaeobacteroides but were replaced by Chlorobium clathratiforme by the end of the study. C. clathratiforme was the only green sulfur bacterium detected during the last 2 years of the analysis, when a shift in dominance from purple sulfur bacteria to green sulfur bacteria was observed in the chemocline. At this time, numbers of purple sulfur bacteria had decreased and those of green sulfur bacteria increased by about 1 order of magnitude and C. clathratiforme represented about 95% of the phototrophic sulfur bacteria. This major change in community structure in the chemocline was accompanied by changes in profiles of turbidity and photosynthetically available radiation, as well as for sulfide concentrations and light intensity. Overall, these findings suggest that a disruption of the chemocline in 2000 may have altered environmental niches and populations in subsequent years.

In Situ Analysis of Phototrophic Sulfur Bacteria in the Chemocline of Meromictic Lake Cadagno (Switzerland)

1999 ◽  
Vol 65 (3) ◽  
pp. 1325-1330 ◽  
Author(s):  
Mauro Tonolla ◽  
Antonella Demarta ◽  
Raffaele Peduzzi ◽  
Dittmar Hahn
Keyword(s):  
Comparative Sequence Analysis ◽  
Meromictic Lake ◽  
Gene Clone ◽  
Rrna Gene ◽  
Oligonucleotide Probes ◽  
Phototrophic Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Tight Cluster ◽  
Type Strains

ABSTRACT Comparative sequence analysis of a 16S rRNA gene clone library from the chemocline of the meromictic Lake Cadagno (Switzerland) revealed the presence of a diverse number of phototrophic sulfur bacteria. Sequences resembled those of rRNA of type strains Chromatium okenii DSM169 and Amoebobacter purpureus DSM4197, as well as those of four bacteria forming a tight cluster with A. purpureus DSM4197 and Lamprocystis roseopersicinaDSM229. In situ hybridization with fluorescent (Cy3 labeled) oligonucleotide probes indicated that all large-celled phototrophic sulfur bacteria in the chemocline of Lake Cadagno were represented byC. okenii DSM169, while small-celled phototrophic sulfur bacteria consisted of four major populations with different distribution profiles in the chemocline indicating different ecophysiological adaptations.

Microbial microstratification, inorganic carbon photoassimilation and dark carbon fixation at the chemocline of the meromictic Lake Cadagno (Switzerland) and its relevance to the food web

2001 ◽  
Vol 63 (1) ◽  
pp. 91-106 ◽  
Author(s):  
Antonio Camacho ◽  
Jonathan Erez ◽  
Alvaro Chicote ◽  
Máximo Florín ◽  
Margaret M. Squires ◽  
...  
Keyword(s):  
Food Web ◽  
Inorganic Carbon ◽  
Carbon Fixation ◽  
Meromictic Lake ◽  
Dark Carbon Fixation

Biomass composition and methods for the determination of metabolic reserve polymers in phototrophic sulfur bacteria

1994 ◽  
Vol 56 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Claudio Del Don ◽  
Kurt W. Hanselmann ◽  
Raffaele Peduzzi ◽  
Reinhard Bachofen
Keyword(s):  
Biomass Composition ◽  
Phototrophic Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Metabolic Reserve

scholarly journals Microbial dark carbon fixation fueled by nitrate enrichment

2021 ◽  
Author(s):  
Joseph H. Vineis ◽  
Ashley N. Bulseco ◽  
Jennifer L. Bowen
Keyword(s):  
Microbial Communities ◽  
Marine Sediments ◽  
Salt Marshes ◽  
Carbon Fixation ◽  
Niche Partitioning ◽  
Coastal Marine Sediments ◽  
Functional Relationships ◽  
Coastal Marine ◽  
Dark Carbon Fixation ◽  
The Impact

Anthropogenic nitrate amendment to coastal marine sediments can increase rates of heterotrophic mineralization and autotrophic dark carbon fixation (DCF). DCF may be favored in sediments where organic matter is biologically unavailable, leading to a microbial community supported by chemoautotrophy. Niche partitioning among DCF communities and adaptations for nitrate metabolism in coastal marine sediments remain poorly characterized, especially within salt marshes. We used genome-resolved metagenomics, phylogenetics, and comparative genomics to characterize the potential niche space, phylogenetic relationships, and adaptations important to microbial communities within nitrate enriched sediment. We found that nitrate enrichment of sediment from discrete depths between 0-25 cm supported both heterotrophs and chemoautotrophs that use sulfur oxidizing denitrification to drive the Calvin-Benson-Bassham (CBB) or reductive TCA (rTCA) DCF pathways. Phylogenetic reconstruction indicated that the nitrate enriched community represented a small fraction of the phylogenetic diversity contained in coastal marine environmental genomes, while pangenomics revealed close evolutionary and functional relationships with DCF microbes in other oligotrophic environments. These results indicate that DCF can support coastal marine microbial communities and should be carefully considered when estimating the impact of nitrate on carbon cycling in these critical habitats.

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