Seeing green bacteria in a new light: genomics-enabled studies of the photosynthetic apparatus in green sulfur bacteria and filamentous anoxygenic phototrophic bacteria

2004 ◽  
Vol 182 (4) ◽  
pp. 265-276 ◽  
Author(s):  
Niels-Ulrik Frigaard ◽  
Donald A. Bryant
Keyword(s):  
Photosynthetic Apparatus ◽  
Green Sulfur Bacteria ◽  
Phototrophic Bacteria ◽  
Anoxygenic Phototrophic Bacteria ◽  
Green Bacteria ◽  
Sulfur Bacteria ◽  
Green Sulfur

scholarly journals “Candidatus Chlorobium masyuteum,” a Novel Photoferrotrophic Green Sulfur Bacterium Enriched From a Ferruginous Meromictic Lake

2021 ◽  
Vol 12 ◽  
Author(s):  
Nicholas Lambrecht ◽  
Zackry Stevenson ◽  
Cody S. Sheik ◽  
Matthew A. Pronschinske ◽  
Hui Tong ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Tca Cycle ◽  
Green Sulfur Bacteria ◽  
Sulfur Compounds ◽  
Electron Donors ◽  
Anoxygenic Phototrophic Bacteria ◽  
Reduced Sulfur Compounds ◽  
Sulfur Bacteria ◽  
Green Sulfur ◽  
Reduced Sulfur

Anoxygenic phototrophic bacteria can be important primary producers in some meromictic lakes. Green sulfur bacteria (GSB) have been detected in ferruginous lakes, with some evidence that they are photosynthesizing using Fe(II) as an electron donor (i.e., photoferrotrophy). However, some photoferrotrophic GSB can also utilize reduced sulfur compounds, complicating the interpretation of Fe-dependent photosynthetic primary productivity. An enrichment (BLA1) from meromictic ferruginous Brownie Lake, Minnesota, United States, contains an Fe(II)-oxidizing GSB and a metabolically flexible putative Fe(III)-reducing anaerobe. “Candidatus Chlorobium masyuteum” grows photoautotrophically with Fe(II) and possesses the putative Fe(II) oxidase-encoding cyc2 gene also known from oxygen-dependent Fe(II)-oxidizing bacteria. It lacks genes for oxidation of reduced sulfur compounds. Its genome encodes for hydrogenases and a reverse TCA cycle that may allow it to utilize H2 and acetate as electron donors, an inference supported by the abundance of this organism when the enrichment was supplied by these substrates and light. The anaerobe “Candidatus Pseudopelobacter ferreus” is in low abundance (∼1%) in BLA1 and is a putative Fe(III)-reducing bacterium from the Geobacterales ord. nov. While “Ca. C. masyuteum” is closely related to the photoferrotrophs C. ferroooxidans strain KoFox and C. phaeoferrooxidans strain KB01, it is unique at the genomic level. The main light-harvesting molecule was identified as bacteriochlorophyll c with accessory carotenoids of the chlorobactene series. BLA1 optimally oxidizes Fe(II) at a pH of 6.8, and the rate of Fe(II) oxidation was 0.63 ± 0.069 mmol day–1, comparable to other photoferrotrophic GSB cultures or enrichments. Investigation of BLA1 expands the genetic basis for phototrophic Fe(II) oxidation by GSB and highlights the role these organisms may play in Fe(II) oxidation and carbon cycling in ferruginous lakes.

Architecture of the photosynthetic complex from a green sulfur bacterium

Science ◽  
2020 ◽  
Vol 370 (6519) ◽  
pp. eabb6350
Author(s):  
Jing-Hua Chen ◽  
Hangjun Wu ◽  
Caihuang Xu ◽  
Xiao-Chi Liu ◽  
Zihui Huang ◽  
...  
Keyword(s):  
Photosynthetic Apparatus ◽  
Green Sulfur Bacteria ◽  
Type I ◽  
Type Ii ◽  
Common Features ◽  
Sulfur Bacteria ◽  
Chlorobaculum Tepidum ◽  
Cryo Electron Microscopy ◽  
Green Sulfur ◽  
Insight Into

The photosynthetic apparatus of green sulfur bacteria (GSB) contains a peripheral antenna chlorosome, light-harvesting Fenna-Matthews-Olson proteins (FMO), and a reaction center (GsbRC). We used cryo–electron microscopy to determine a 2.7-angstrom structure of the FMO-GsbRC supercomplex from Chlorobaculum tepidum. The GsbRC binds considerably fewer (bacterio)chlorophylls [(B)Chls] than other known type I RCs do, and the organization of (B)Chls is similar to that in photosystem II. Two BChl layers in GsbRC are not connected by Chls, as seen in other RCs, but associate with two carotenoid derivatives. Relatively long distances of 22 to 33 angstroms were observed between BChls of FMO and GsbRC, consistent with the inefficient energy transfer between these entities. The structure contains common features of both type I and type II RCs and provides insight into the evolution of photosynthetic RCs.

scholarly journals Molecular Physiology of Anaerobic Phototrophic Purple and Green Sulfur Bacteria

2021 ◽  
Vol 22 (12) ◽  
pp. 6398
Author(s):  
Ivan Kushkevych ◽  
Jiří Procházka ◽  
Márió Gajdács ◽  
Simon K.-M. R. Rittmann ◽  
Monika Vítězová
Keyword(s):  
Hydrogen Sulfide ◽  
Molecular Mechanisms ◽  
Photosynthetic Apparatus ◽  
Green Sulfur Bacteria ◽  
Bacterial Photosynthesis ◽  
Molecular Physiology ◽  
Physiological Processes ◽  
Sulfur Bacteria ◽  
Phototrophic Microorganisms ◽  
Green Sulfur

There are two main types of bacterial photosynthesis: oxygenic (cyanobacteria) and anoxygenic (sulfur and non-sulfur phototrophs). Molecular mechanisms of photosynthesis in the phototrophic microorganisms can differ and depend on their location and pigments in the cells. This paper describes bacteria capable of molecular oxidizing hydrogen sulfide, specifically the families Chromatiaceae and Chlorobiaceae, also known as purple and green sulfur bacteria in the process of anoxygenic photosynthesis. Further, it analyzes certain important physiological processes, especially those which are characteristic for these bacterial families. Primarily, the molecular metabolism of sulfur, which oxidizes hydrogen sulfide to elementary molecular sulfur, as well as photosynthetic processes taking place inside of cells are presented. Particular attention is paid to the description of the molecular structure of the photosynthetic apparatus in these two families of phototrophs. Moreover, some of their molecular biotechnological perspectives are discussed.

scholarly journals Signature pigments of green sulfur bacteria in lower Pleistocene deposits from the Banyoles lacustrine area (Spain)

2005 ◽  
Vol 34 (2) ◽  
pp. 271-280 ◽  
Author(s):  
N. Mallorquí ◽  
J.B. Arellano ◽  
C.M. Borrego ◽  
L.J. Garcia-Gil
Keyword(s):  
Green Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Lower Pleistocene ◽  
Green Sulfur

scholarly journals Differential RNA Sequencing Implicates Sulfide as the Master Regulator of S 0 Metabolism in Chlorobaculum tepidum and Other Green Sulfur Bacteria

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Jacob M. Hilzinger ◽  
Vidhyavathi Raman ◽  
Kevin E. Shuman ◽  
Brian J. Eddie ◽  
Thomas E. Hanson
Keyword(s):  
Gene Expression ◽  
Elemental Sulfur ◽  
Green Sulfur Bacteria ◽  
Electron Donors ◽  
Reduced Sulfur Compounds ◽  
Promoter Elements ◽  
Content Type ◽  
Sulfur Bacteria ◽  
Chlorobaculum Tepidum ◽  
Green Sulfur

ABSTRACT The green sulfur bacteria ( Chlorobiaceae ) are anaerobes that use electrons from reduced sulfur compounds (sulfide, S 0 , and thiosulfate) as electron donors for photoautotrophic growth. Chlorobaculum tepidum , the model system for the Chlorobiaceae , both produces and consumes extracellular S 0 globules depending on the availability of sulfide in the environment. These physiological changes imply significant changes in gene regulation, which has been observed when sulfide is added to Cba. tepidum growing on thiosulfate. However, the underlying mechanisms driving these gene expression changes, i.e., the specific regulators and promoter elements involved, have not yet been defined. Here, differential RNA sequencing (dRNA-seq) was used to globally identify transcript start sites (TSS) that were present during growth on sulfide, biogenic S 0 , and thiosulfate as sole electron donors. TSS positions were used in combination with RNA-seq data from cultures growing on these same electron donors to identify both basal promoter elements and motifs associated with electron donor-dependent transcriptional regulation. These motifs were conserved across homologous Chlorobiaceae promoters. Two lines of evidence suggest that sulfide-mediated repression is the dominant regulatory mode in Cba. tepidum . First, motifs associated with genes regulated by sulfide overlap key basal promoter elements. Second, deletion of the Cba. tepidum 1277 ( CT1277 ) gene, encoding a putative regulatory protein, leads to constitutive overexpression of the sulfide:quinone oxidoreductase CT1087 in the absence of sulfide. The results suggest that sulfide is the master regulator of sulfur metabolism in Cba. tepidum and the Chlorobiaceae . Finally, the identification of basal promoter elements with differing strengths will further the development of synthetic biology in Cba. tepidum and perhaps other Chlorobiaceae . IMPORTANCE Elemental sulfur is a key intermediate in biogeochemical sulfur cycling. The photoautotrophic green sulfur bacterium Chlorobaculum tepidum either produces or consumes elemental sulfur depending on the availability of sulfide in the environment. Our results reveal transcriptional dynamics of Chlorobaculum tepidum on elemental sulfur and increase our understanding of the mechanisms of transcriptional regulation governing growth on different reduced sulfur compounds. This report identifies genes and sequence motifs that likely play significant roles in the production and consumption of elemental sulfur. Beyond this focused impact, this report paves the way for the development of synthetic biology in Chlorobaculum tepidum and other Chlorobiaceae by providing a comprehensive identification of promoter elements for control of gene expression, a key element of strain engineering.

Linearly polarized light absorption spectra of chlorosomes, light-harvesting antennas of photosynthetic green sulfur bacteria

2010 ◽  
Vol 484 (4-6) ◽  
pp. 333-337 ◽  
Author(s):  
Hitoshi Tamiaki ◽  
Shingo Tateishi ◽  
Shosuke Nakabayashi ◽  
Yutaka Shibata ◽  
Shigeru Itoh
Keyword(s):  
Absorption Spectra ◽  
Light Absorption ◽  
Light Harvesting ◽  
Polarized Light ◽  
Green Sulfur Bacteria ◽  
Sulfur Bacteria ◽  
Linearly Polarized ◽  
Green Sulfur
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