scholarly journals Anoxygenic phototrophic Chloroflexota member uses a Type I reaction center

2020 ◽  
Author(s):  
J. M. Tsuji ◽  
N. A. Shaw ◽  
S. Nagashima ◽  
J. J. Venkiteswaran ◽  
S. L. Schiff ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Reaction Center ◽  
Photosynthetic Reaction Center ◽  
Model System ◽  
Type I ◽  
Gene Exchange ◽  
Type Ii ◽  
Experimental Lakes Area ◽  
Light Energy Conversion ◽  
Evolution Of Photosynthesis

AbstractPhototrophic bacteria within the Chloroflexota phylum are puzzling in their evolutionary origin. Previously known phototrophic Chloroflexota members use a Type II photosynthetic reaction center for light energy conversion but contain other photosynthesis machinery associated with Type I reaction center-utilizing phototrophs. We sampled an iron-rich boreal lake at the IISD-Experimental Lakes Area and enriched ‘Candidatus Chlorohelix allophototropha’, a phototrophic Chloroflexota member that uses a Type I reaction center. Phylogenomic evidence suggests that ancestors of ‘Ca. Chx. allophototropha’ served as a bridge for historic phototrophy gene exchange within the phylum. The Chloroflexota now represents the only bacterial phylum outside the Cyanobacteria where both major classes of photosynthetic reaction center occur and can serve as a model system to explore fundamental questions about the evolution of photosynthesis.

scholarly journals Type II photosynthetic reaction center genes of avocado (Persea americana Mill.) bark microbial communities are dominated by aerobic anoxygenic Alphaproteobacteria

2020 ◽  
Author(s):  
Eneas Aguirre-von-Wobeser
Keyword(s):  
Microbial Communities ◽  
Reaction Center ◽  
Photosynthetic Reaction Center ◽  
Persea Americana ◽  
Algorithm Analysis ◽  
Tree Bark ◽  
Oxygenic Photosynthesis ◽  
Type Ii ◽  
Additional Energy ◽  
Anoxygenic Photosynthesis

AbstractThe tree bark environment is an important microbial habitat distributed worldwide on thrillions of trees. However, the microbial communities of tree bark are largely unknown, with most studies on plant aerial surfaces focused on the leaves. Recently, we presented a metagenomic study of bark microbial communities from avocado. In these communities, oxygenic and anoxygenic photosynthesis genes were very abundant, especially when compared to rhizospheric soil from the same trees. In this work, Evolutionary Placement Algorithm analysis was performed on metagenomic reads orthologous to the PufLM gene cluster, encoding for the bacterial type II photosynthetic reaction center. These photosynthetic genes were found affiliated to different groups of bacteria, mostly aerobic anoxygenic photosynthetic Alphaproteobacteria, including Sphingomonas, Methylobacterium and several Rhodospirillales. These results suggest that anoxygenic photosynthesis in avocado bark microbial communities functions primarily as additional energy source for heterotrophic growth. Together with our previous results, showing a large abundance of cyanobacteria in these communities, a picture emerges of the tree holobiont, where light penetrating the trees canopies and reaching the inner stems, including the trunk, is probably utilized by cyanobacteria for oxygenic photosynthesis, and the far-red light aids the growth of aerobic anoxygenic photosynthetic bacteria.

Thermodynamics of the Electron Acceptors inHeliobacterium modesticaldum: An Exemplar of an Early Homodimeric Type I Photosynthetic Reaction Center

Biochemistry ◽  
2016 ◽  
Vol 55 (16) ◽  
pp. 2358-2370 ◽  
Author(s):  
Bryan Ferlez ◽  
John Cowgill ◽  
Weibing Dong ◽  
Christopher Gisriel ◽  
Su Lin ◽  
...  
Keyword(s):  
Reaction Center ◽  
Photosynthetic Reaction Center ◽  
Electron Acceptors ◽  
Type I

scholarly journals Phylogeny of Anoxygenic Photosynthesis Based on Sequences of Photosynthetic Reaction Center Proteins and a Key Enzyme in Bacteriochlorophyll Biosynthesis, the Chlorophyllide Reductase

2019 ◽  
Vol 7 (11) ◽  
pp. 576 ◽  
Author(s):  
Johannes F. Imhoff ◽  
Tanja Rahn ◽  
Sven Künzel ◽  
Sven C. Neulinger
Keyword(s):  
16S Rrna ◽  
Reaction Center ◽  
Purple Bacteria ◽  
Photosynthetic Reaction Center ◽  
Phototrophic Bacteria ◽  
Anoxygenic Phototrophic Bacteria ◽  
Type Ii ◽  
Phylogenetic Relations ◽  
Key Enzyme ◽  
Bacteriochlorophyll Biosynthesis

Photosynthesis is a key process for the establishment and maintenance of life on earth, and it is manifested in several major lineages of the prokaryote tree of life. The evolution of photosynthesis in anoxygenic photosynthetic bacteria is of major interest as these have the most ancient roots of photosynthetic systems. The phylogenetic relations between anoxygenic phototrophic bacteria were compared on the basis of sequences of key proteins of the type-II photosynthetic reaction center, including PufLM and PufH (PuhA), and a key enzyme of bacteriochlorophyll biosynthesis, the light-independent chlorophyllide reductase BchXYZ. The latter was common to all anoxygenic phototrophic bacteria, including those with a type-I and those with a type-II photosynthetic reaction center. The phylogenetic considerations included cultured phototrophic bacteria from several phyla, including Proteobacteria (138 species), Chloroflexi (five species), Chlorobi (six species), as well as Heliobacterium modesticaldum (Firmicutes), Chloracidobacterium acidophilum (Acidobacteria), and Gemmatimonas phototrophica (Gemmatimonadetes). Whenever available, type strains were studied. Phylogenetic relationships based on a photosynthesis tree (PS tree, including sequences of PufHLM-BchXYZ) were compared with those of 16S rRNA gene sequences (RNS tree). Despite some significant differences, large parts were congruent between the 16S rRNA phylogeny and photosynthesis proteins. The phylogenetic relations demonstrated that bacteriochlorophyll biosynthesis had evolved in ancestors of phototrophic green bacteria much earlier as compared to phototrophic purple bacteria and that multiple events independently formed different lineages of aerobic phototrophic purple bacteria, many of which have very ancient roots. The Rhodobacterales clearly represented the youngest group, which was separated from other Proteobacteria by a large evolutionary gap.

Sign in / Sign up

Export Citation Format

Share Document