1. Advances in the Biology of Phototrophic Bacteria.
- Author
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Imhoff, Johannes F. and Imhoff, Johannes F.
- Subjects
Research & information: general ,Alphaproteobacteria ,CAS assay ,ChpT ,Chromocurvus halotolerans strain EG19 ,Crp/Fnr ,Dnr ,Heliorestis convoluta ,Irr ,IscR ,OxyR ,RegA ,Rhodobacter capsulatus ,Rhodobacter sphaeroides ,Rhodobacteraceae ,Rhodovulum ,Sphingomonadaceae ,adhesion protein ,aerobic anoxygenic phototrophic bacteria ,aerobic anoxygenic phototrophs ,alkaliphilic bacteria ,anoxygenic phototroph ,anoxygenic phototrophic bacteria ,antisense promoters ,bacteriochlorophyll a ,bacteriochlorophyll biosynthesis ,bacteriochlorophyll g ,bioerosion ,biological soil crust ,carbon fixation ,drylands ,e-pili ,ectoine biosynthesis ,energy metabolism ,euendolith ,evolution of anoxygenic photosynthesis ,filamentous anoxygenic phototroph ,gene transfer agent ,genomes of photosynthetic bacteria ,glycine betaine biosynthesis ,green sulfur bacteria ,heliobacteria ,hot springs ,iron-sulfur cluster ,isc genes ,large multiheme cytochrome ,massive blooms ,metagenomic binning ,metallophore ,metatranscriptomics ,microbial mats ,microbiome ,motility ,n/a ,niche partitioning ,nitric oxide ,nitrogen fixing cyanobacteria ,osmotic adaptation ,photooxidative stress ,photosynthesis genes ,photosynthetic reaction center proteins ,photosynthetic symbionts ,phototrophic purple bacteria ,phylogenomics ,phylogeny ,phylogeny of osmolyte biosynthesis ,proteomics ,pufM gene ,purple nonsulfur bacteria ,quorum sensing ,rhodopsin ,siderophore ,soda lake ,stress defense ,suf genes ,syntrophy ,transcriptomics - Abstract
Summary: The application of genomic, transcriptomic, and proteomic analyses brings new dimensions to our understanding of the biology of phototrophic bacteria. Comparing gene sequences of photosynthetic reaction center proteins and a key enzyme of bacteriochlorophyll biosynthesis from more than 150 genomes demonstrates the ancient roots of phototrophic bacteria. The presence and phylogeny of biosynthetic pathways of the compatible solutes ectoine and glycine betaine define groups of marine and halophilic phototrophic bacteria. The wide range of ecological niches conquered during evolution is demonstrated by the adaptation of cyanobacterial genera Scytonema, Tolypothrix, and Nostoc to different temperature ranges and the adaptation of Heliorestis species to alkaline habitats. Differences between phototrophic purple bacteria from marine and freshwater habitats are reflected in the preference for sulfidic and non-sulfidic niches. Also, a high proportion of siderophore producers was found among isolates from freshwater sources opposed to those from salty habitats . The primary colonization of carbonate rocks by a group of novel endolithic cyanobacteria and the following successions were studied over 9 months. The genomic characterization of the aerobic Dinoroseobacter strain AAP5, the strictly anaerobic and syntrophic Prosthecochloris ethylica, and the strictly anaerobic Heliorestis convoluta is reported. Significant differences in relation to oxygen are reflected in oxygen production by some species, oxygen tolerance over a wide range of concentrations, and the use of oxygen for energy generation or a strictly anaerobic lifestyle. Relations to oxygen are highlighted in papers on photooxidative stress, regulation of iron-sulfur cluster formation, and interactions of redox regulators. In situ metatranscriptomic and proteomic studies demonstrate the high metabolic flexibility of Chloroflexus aggregans in a hot spring microbial mat and show its adaptation to the changing conditions over day and night periods by a well-coordinated regulation of key metabolic processes for both phototrophic and chemotrophic growth.