Comparative Enzymology of Sulfite Oxidation in Thiocapsa roseopersicina Strains 6311, M1 and BBS under Chemotrophic and Phototrophic Conditions

1989 ◽  
Vol 44 (7-8) ◽  
pp. 617-622 ◽  
Author(s):  
Christiane Dahl ◽  
Hans G. Trüper
Keyword(s):  
Growth Conditions ◽  
Reduced Sulfur Compounds ◽  
Atp Sulfurylase ◽  
Purple Sulfur Bacterium ◽  
Sulfite Oxidation ◽  
Aps Reductase ◽  
Comparative Enzymology ◽  
Membrane Bound ◽  
Specific Activities ◽  
Phototrophic Growth

The purple sulfur bacterium T. roseopersicina is able to grow chemoautotrophically in the dark under micro- to semiaerobic conditions. Under the latter cell yield and growth rate are considerably reduced. During chemo- and phototrophic growth reduced sulfur compounds are metabolized by the same pathway, i.e. oxidized to sulfate via adenylylsulfate. APS reductase (EC 1.8.99.2), ADP sulfurylase (EC 2.7.7.5) and ATP sulfurylase (EC 2.7.7.4) could be shown in all the strains tested, whereas only strain BBS contained an AMP independent sulfite-oxidizing activity under photo- as well as under chemotrophic conditions. Not only ADP but also ATP sulfurylase perform a dissimilatory function proven by their high specific activities. In contrast to the enzyme of T. roseopersicina strain 6311 APS reductases from strains M1 and BBS are strictly membrane-bound. The enzyme from strain M1 was solubilized, enriched and characterized. While the KM values of purified APS reductase remain unaffected, specific activities of APS reductase, ATP and ADP sulfurylase are increased substantially under chemotrophic growth conditions.

scholarly journals Key Role for Sulfur in Peptide Metabolism and in Regulation of Three Hydrogenases in the Hyperthermophilic ArchaeonPyrococcus furiosus

2001 ◽  
Vol 183 (2) ◽  
pp. 716-724 ◽  
Author(s):  
Michael W. W. Adams ◽  
James F. Holden ◽  
Angeli Lal Menon ◽  
Gerrit J. Schut ◽  
Amy M. Grunden ◽  
...  
Keyword(s):  
Growth Rates ◽  
Elemental Sulfur ◽  
Pyrococcus Furiosus ◽  
Growth Conditions ◽  
Growth Media ◽  
Hyperthermophilic Archaeon ◽  
Order Of Magnitude ◽  
Membrane Bound ◽  
Peptide Metabolism ◽  
Specific Activities

ABSTRACT The hyperthermophilic archaeon Pyrococcus furiosusgrows optimally at 100°C by the fermentation of peptides and carbohydrates. Growth of the organism was examined in media containing either maltose, peptides (hydrolyzed casein), or both as the carbon source(s), each with and without elemental sulfur (S0). Growth rates were highest on media containing peptides and S0, with or without maltose. Growth did not occur on the peptide medium without S0. S0 had no effect on growth rates in the maltose medium in the absence of peptides. Phenylacetate production rates (from phenylalanine fermentation) from cells grown in the peptide medium containing S0 with or without maltose were the same, suggesting that S0 is required for peptide utilization. The activities of 14 of 21 enzymes involved in or related to the fermentation pathways of P. furiosus were shown to be regulated under the five different growth conditions studied. The presence of S0 in the growth media resulted in decreases in specific activities of two cytoplasmic hydrogenases (I and II) and of a membrane-bound hydrogenase, each by an order of magnitude. The primary S0-reducing enzyme in this organism and the mechanism of the S0 dependence of peptide metabolism are not known. This study provides the first evidence for a highly regulated fermentation-based metabolism in P. furiosus and a significant regulatory role for elemental sulfur or its metabolites.

scholarly journals Glucose Signaling Pathway and Growth Conditions Regulate Gene Expression in Retrotransposon Ty2

2009 ◽  
Vol 64 (7-8) ◽  
pp. 526-532 ◽  
Author(s):  
Sezai Türkel ◽  
Özgür Bayram ◽  
Elif Arık
Keyword(s):  
Gene Expression ◽  
Growth Conditions ◽  
Glucose Sensors ◽  
Yeast Cells ◽  
Growth Stages ◽  
Regulate Gene Expression ◽  
Glucose Signaling ◽  
Yeast Cultures ◽  
Membrane Bound ◽  
High Level

Gene expression in the yeast retrotransposon Ty2 is regulated at transcriptional and translational levels. In this study, we have shown that the transcription of Ty2 is partially dependent on the membrane-bound glucose sensors Gpr1p and Mth1p in Saccharomyces cerevisiae. Transcription of Ty2 decreased approx. 3-fold in the gpr1, mth1 yeast mutant. Moreover, our results revealed that the transcription of Ty2 fluctuates during the growth stages of S. cerevisae. Both transcription and the frameshift rate of Ty2 rapidly dropped when the stationary stage yeast cells were inoculated into fresh medium. There was an instant activation of Ty2 transcription and a high level expression during the entire logarithmic stage of yeast growth. However, the transcription of Ty2 decreased 2-fold when the yeast cultures entered the stationary stage. The frameshift rate in Ty2 also varied depending on the growth conditions. The highest frameshift level was observed during the mid-logarithmic stage. It decreased up to 2-fold during the stationary stage. Furthermore, we have found that the frameshift rate of Ty2 diminished at least 5-fold in slowly growing yeasts. These results indicate that the transcription and the frameshift efficiency are coordinately regulated in the retrotransposon Ty2 depending on the growth conditions of S. cerevisiae.

Effect of Differential Sulfur Nutrition on the Specific Activity of ATP Sulfurylase in Mature Grain From Five Wheat Cultivars (Triticum aestivum L.)

1987 ◽  
Vol 14 (3) ◽  
pp. 239 ◽  
Author(s):  
MJ Archer
Keyword(s):  
Grain Yield ◽  
Specific Activity ◽  
Triticum Aestivum L ◽  
Quality Data ◽  
Sand Culture ◽  
Wheat Cultivars ◽  
Sulfur Deficiency ◽  
Atp Sulfurylase ◽  
Specific Activities ◽  
Sulfur Nutrition

Wholemeal grists of five wheat cultivars (T. aestivum L.) - Gabo, Olympic, Stockade, Insignia and Summit - grown in sand culture supplied with low (10 �M), medium (375 �M) and high (875 �M) concentrations of sulfur, were analysed for their specific activities of ATP sulfurylase (EC 2.7.7.4, ATP:sulfate adenylyltransferase). Under sulfur deficient conditions, residual activities were significantly higher in Gabo, Olympic and Stockade. Olympic maintained significantly higher activities at both the medium and high sulfur concentrations. All cultivars except Summit showed significantly lower activities when the sulfur deficiency was corrected. The results are discussed in relation to grain yield per plant, yield components, grain N, S, P contents and Pelshenke quality data. Grain yield per plant and ATP sulfurylase activity were positively correlated at all sulfur levels.

scholarly journals Free and membrane-bound forms of bacterial cytochrome c4

1988 ◽  
Vol 252 (2) ◽  
pp. 427-435 ◽  
Author(s):  
G W Pettigrew ◽  
K R Brown
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Azotobacter Vinelandii ◽  
Pseudomonas Stutzeri ◽  
Growth Conditions ◽  
Free Form ◽  
Aerobic Growth ◽  
Cytochromes C ◽  
Membrane Bound ◽  
Solubilized Form ◽  
Attached Form

Cytochrome c4 was isolated from cells of Pseudomonas aeruginosa, Pseudomonas stutzeri and Azotobacter vinelandii. The dihaem nature, Mr of approx. 20,000 and ferrohaem spectra in the region of the alpha- and beta-peaks define this family of cytochromes c. The behaviour of the holocytochromes in SDS was atypical, but removal of the haem groups resulted in a normal migration. In all three organisms most of the cytochrome c4 was tightly bound to the membrane, but some free cytochrome was detected. The membrane-attached cytochrome could be extracted with butanol, and this solubilized form was then indistinguishable in properties from the free form. Denitrifying rather than aerobic growth conditions hardly affected the total cytochrome c4 in the two pseudomonads, but there was slightly more free form and less membrane-attached form in denitrifying growth. The nature of the attachment of cytochrome c4 to the membrane is discussed and a model is proposed for the process of solubilization.

scholarly journals Complex formation between recombinant ATP sulfurylase and APS reductase ofAllium cepa(L.)

FEBS Letters ◽  
2007 ◽  
Vol 581 (22) ◽  
pp. 4139-4147 ◽  
Author(s):  
Mathew Cumming ◽  
Susanna Leung ◽  
John McCallum ◽  
Michael T. McManus
Keyword(s):  
Complex Formation ◽  
Atp Sulfurylase ◽  
Aps Reductase ◽  
Ofallium Cepa

scholarly journals Differential Regulation of Soluble and Membrane-Bound Inorganic Pyrophosphatases in the Photosynthetic Bacterium Rhodospirillum rubrum Provides Insights into Pyrophosphate-Based Stress Bioenergetics

2004 ◽  
Vol 186 (16) ◽  
pp. 5418-5426 ◽  
Author(s):  
Rosa L. López-Marqués ◽  
José R. Pérez-Castiñeira ◽  
Manuel Losada ◽  
Aurelio Serrano
Keyword(s):  
Salt Stress ◽  
Rhodospirillum Rubrum ◽  
Photosynthetic Bacterium ◽  
Growth Conditions ◽  
Anaerobic Growth ◽  
Sequence Motif ◽  
Batch Cultures ◽  
Time Patterns ◽  
Membrane Bound ◽  
Respiratory Conditions

ABSTRACT Soluble and membrane-bound inorganic pyrophosphatases (sPPase and H+-PPase, respectively) of the purple nonsulfur bacterium Rhodospirillum rubrum are differentially regulated by environmental growth conditions. Both proteins and their transcripts were found in cells of anaerobic phototrophic batch cultures along all growth phases, although they displayed different time patterns. However, in aerobic cells that grow in the dark, which exhibited the highest growth rates, Northern and Western blot analyses as well as activity assays demonstrated high sPPase levels but no H+-PPase. It is noteworthy that H+-PPase is highly expressed in aerobic cells under acute salt stress (1 M NaCl). H+-PPase was also present in anaerobic cells growing at reduced rates in the dark under either fermentative or anaerobic respiratory conditions. Since H+-PPase was detected not only under all anaerobic growth conditions but also under salt stress in aerobiosis, the corresponding gene is not invariably repressed by oxygen. Primer extension analyses showed that, under all anaerobic conditions tested, the R. rubrum H+-PPase gene utilizes two activator-dependent tandem promoters, one with an FNR-like sequence motif and the other with a RegA motif, whereas in aerobiosis under salt stress, the H+-PPase gene is transcribed from two further tandem promoters involving other transcription factors. These results demonstrate a tight transcriptional regulation of the H+-PPase gene, which appears to be induced in response to a variety of environmental conditions, all of which constrain cell energetics.

Nuclear membrane-bound UDPglucuronosyltransferase of rat liver

1982 ◽  
Vol 60 (10) ◽  
pp. 972-979 ◽  
Author(s):  
Jan Zaleski ◽  
Surendra K. Bansal ◽  
Teresa Gessner
Keyword(s):  
Endoplasmic Reticulum ◽  
High Activity ◽  
Rat Liver ◽  
Nuclear Membrane ◽  
Glucuronic Acid ◽  
Microsomal Enzyme ◽  
Subcellular Membrane ◽  
Membrane Bound ◽  
Specific Activities

Some properties of rat liver nuclear membrane-bound UDPglucuronosyltransferase were compared with those of the endoplasmic reticulum bound enzyme. The activity of nuclear membrane-bound UDPglucuronosyltransferase was stimulated only about 1.5-fold by Lubrol WX. Under the same conditions microsomal UDPglucuronosyltransferase was, as usual, highly activated (up to 10-fold), when 4-nitrophenol was the acceptor of glucuronic acid. Specific activities of the detergent-activated enzyme were similar in microsomal and nuclear membrane preparations, when the following aglycone substrates were used: 4-methylumbelliferone, 4-nitrophenol, 1-naphthol, phenolphthalein, and testosterone. Apparent Km values for UDP-glucuronic acid ranged between 0.15–0.25 mM for glucuronidation of 4-nitrophenol and 1-naphthol, by either Lubrol WX activated or non-activated, nuclear membrane-bound UDPglucuronosyltransferase. These values were comparable to those found for detergent activated microsomal enzyme. The results show a similarity in behavior of detergent-activated UDPglucuronosyltransferase regardless of subcellular membrane source and, therefore, suggest the association of the same glucuronosyltransferase with nuclear membrane and endoplasmic reticulum. A possible significance of the presence of high activity of this enzyme in nuclear membrane is discussed.

scholarly journals Optimizing bioreactor growth of the smallest eukaryote

2018 ◽  
Author(s):  
Chuck R. Smallwood ◽  
Eric A. Hill ◽  
William Chrisler ◽  
Jory Brookreson ◽  
James E. Evans
Keyword(s):  
Growth Conditions ◽  
Energy Resources ◽  
Total Biomass ◽  
Nutrient Requirements ◽  
Free Living ◽  
Nutrient Pools ◽  
Photosynthetic Organisms ◽  
Ostreococcus Tauri ◽  
Phototrophic Growth ◽  
Doubling Times

AbstractPhotosynthetic organisms are adept at circumventing nutrient deprivation. Microalgae in particular present novel adaptations to nutrient and light starvation since they can scavenge external and internal nutrient pools to redistribute energy resources for survival. In this report, a turbidostatic photobioreactor was used to characterize environmental conditions and nutrient requirements for cultures of the smallest free-living eukaryote Ostreococcus tauri. Optimized growth conditions were identified that enable 4-times faster phototrophic growth-rates while increasing total biomass 10-fold. By achieving phototrophic doubling times shorter than 6 hours, these results highlight the potential of this smallest eukaryote for future industrial bioproduct applications.

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