The filamentous anoxygenic phototrophic bacterium Oscillochloris trichoides DG-6 has been studied, and it has been shown that there are no lipopolysaccharides on the cell surface. Fatty acids hydroxylated at the C3 position, amino sugars and phosphate-containing compounds characteristic of lipid A have also not been found. The genes encoding for proteins responsible for the synthesis of lipopolysaccharides and the genes for the transport system, usually localized in the outer membrane of Gram-negative bacteria, have not been detected in the genome.
View Article and Find Full Text PDFFor the first decade following its description in 1954, the Calvin-Benson cycle was considered the sole pathway of autotrophic CO assimilation. In the early 1960s, experiments with fermentative bacteria uncovered reactions that challenged this concept. Ferredoxin was found to donate electrons directly for the reductive fixation of CO into alpha-keto acids via reactions considered irreversible.
View Article and Find Full Text PDFMGU-K5 is an anoxygenic, purple, photoheterotrophic, nonsulfur alphaproteobacterium. Unlike most purple nonsulfur bacteria, MGU-K5 is unable to grow aerobically under chemoorganotrophic conditions. Here, we present the draft genome sequence of to provide insights into its physiology.
View Article and Find Full Text PDFMicrobiology (Reading)
January 2015
It is commonly accepted that green filamentous anoxygenic phototrophic (FAP) bacteria are the most ancient representatives of phototrophic micro-organisms. Modern FAPs belonging to the order Chloroflexales are divided into two suborders: Chloroflexineae and Roseiflexineae. Representatives of Roseiflexineae lack chlorosomes and synthesize bacteriochlorophyll a, whereas those of Chloroflexineae synthesize bacteriochlorophylls a and c and utilize chlorosomes for light harvesting.
View Article and Find Full Text PDFHere we show that carbon dioxide (CO2) stimulates budding and shortens the lag-period of Saccharomyces cerevisiae cultures, grown on specific weak media. CO2 can be both exogenous and secreted by another growing yeast culture. We also show that this effect can be observed only in the lag-period, and demonstrate minimal doses and duration of culture exposition to CO2.
View Article and Find Full Text PDFOscillochloris trichoides is a mesophilic, filamentous, photoautotrophic, nonsulfur, diazotrophic bacterium which is capable of carbon dioxide fixation via the reductive pentose phosphate cycle and possesses no assimilative sulfate reduction. Here, we present the draft genome sequence of Oscillochloris trichoides subsp. DG-6, the type strain of the species, which has permitted the prediction of genes for carbon and nitrogen metabolism and for the light-harvesting apparatus.
View Article and Find Full Text PDFItaconate is known as a potent inhibitor of isocitrate lyase. Unexpectedly, itaconate was a strong inhibitor of acetate and propionate assimilation in isocitrate lyase-negative purple non-sulfur bacterium Rhodospirillum rubrum. It was shown that in cell extracts of R.
View Article and Find Full Text PDFStudies on autotrophic CO2 fixation by the filamentous anoxygenic photosynthetic bacterium Oscillochloris trichoides strain DG-6 demonstrated that, unlike other green bacteria, this organism metabolized CO2 via the reductive pentose phosphate cycle. Both key enzymes of this cycle--ribulose-1,5-bisphosphate carboxylase/oxygenase and phosphoribulokinase--were detected in cell extracts. The main product of ribulose 1,5-bisphosphate-dependent CO2 fixation was 3-phosphoglyceric acid.
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