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The pyruvate dehydrogenase complex from the photosynthetic bacterium Rhodospirillum rubrum was associated with the membrane fraction both in heterotrophically and photosynthetically grown cells. The complex was separated from the membranes and partially purified by precipitation with MgSO4 and gelfiltration through Sepharose 4B. The purified complex had a(More)
In Rhodospirillum rubrum, inorganic pyrophosphatase activity is observed in both the cytoplasmic and membrane fractions. The soluble enzyme accounts for about 80% of the total activity in crude extracts, and is the subject of this report. Zn(2+) is required for both activity and stability of the enzyme, which has a molecular weight of approximately 90,000(More)
Soluble inorganic pyrophosphatases of five species of nonsulfur purple bacteria were investigated in respect to reaction kinetics, regulatory behavior, and other characteristics. The enzymes appear to fall into two groups with correlated properties. The pyrophosphatases of Rhodopseudomonas capsulata and R. spheroides have molecular weights of approximately(More)
30 strains of xylanolytic thermophilic actinomycetes were isolated from composted grass and cattle manure and identified as members of the genera Thermomonospora, Saccharomonospora, Microbispora, Streptomyces and Actinomadura. Screening of these strains for extracellular xylanase indicated that strains of Saccharomonospora and Microbispora generally were(More)
Transposon Tn5 mutagenesis was used to isolate mutants of Rhodospirillum rubrum which lack uptake hydrogenase (Hup) activity. Three Tn5 insertions mapped at different positions within the same 13-kb EcoRI fragment (fragment E1). Hybridization experiments revealed homology to the structural hydrogenase genes hupSLM from Rhodobacter capsulatus and hupSL from(More)
A dissimilatory nitrite reductase from the facultatively phototrophic bacterium, Rhodopseudomonas palustris strain 1a1 was studied. A basic level of the enzyme (10-50 mU/mg protein) was measured in dark, aerated and anaerobic, photosynthetic cultures. A marked derepression of enzyme synthesis occurred under conditions of oxygen limitation (200-300 mU/mg(More)
Two endoxylanases were isolated from the xylanolytic enzyme system of the thermophilic actinomycete Microtetraspora flexuosa SIIX, and purified by ammonium sulfate fractionation, DEAE-Sepharose chromatography, gel filtration on Sephacryl S 200 and fast protein liquid chromatography on Q-Sepharose. The molecular masses of xylanase I and II were 26.3 and 16.8(More)
A pyrophosphate-dependent fructose-6-phosphate phosphotransferase from the photosynthetic bacterium Rhodospirillum rubrum was partially purified and characterized in respect to kinetic and regulatory properties. The enzyme had a molecular weight of about 95 000 dalton and required Mg2+-ions for catalysis and maintenance of activity. The phosphotransferase(More)
During the course of isolating and identifying purple non-sulfur bacteria, one nitrate-reducing strain was isolated which did not fit the description of any other purple non-sulfur bacterium known to date. The isolate had rod-shaped cells that contained lamellar intracytoplasmic membranes and produced red cultures. Absorption maxima of photosynthetically(More)