Metabolic activities of sheep erythrocytes. I. Glycolytic activities

1962 ◽  
Vol 13 (1) ◽  
pp. 31 ◽  
Author(s):  
RA Leng ◽  
EF Annison
Keyword(s):  
Carbon Dioxide ◽  
Methylene Blue ◽  
Lactic Acid ◽  
Oxygen Uptake ◽  
Pentose Phosphate Pathway ◽  
Glucose Oxidation ◽  
Lactic Acid Production ◽  
Pentose Phosphate ◽  
Sheep Erythrocytes ◽  
Metabolic Activities

Sheep erythrocytes, which in most animals are impermeable to glucose, show low glycolytic activities relative to human cells. When 14C-labelled glucose was incubated with erythrocyte suspensions the oxygen uptake was 10.9 ± 1.8 µl/hr/ml of cells (5 replications), and glucose oxidation (measured by recovery of [14C]carbon dioxide) was 0.03 ± 0.007 µmole/hr/ml (5). Addition of methylene blue (0.4 µmole/ ml) increased oxygen uptake to 56 ± 3.5 µl/hr/ml (5) and glucose oxidation to 0.36 ± 0.02 µmole/hr/ml. Lactic acid production was increased from 1 .5 ± 0.06 µmole/hr/ml (7) to 1.7 ± 0.11 µmole/hr/ml (7) in the presence of methylene blue. Comparison of the yields of [14C]carbon dioxide from [1-14C]glucose and uniformly labelled [14C]glucose indicated that when stimulated by methylene blue 80–100% of glycolysis proceeded by the pentose phosphate pathway, but in the unstimulated system the alternative aerobic pathway accounted for only about 15% of total glycolysis.

scholarly journals Homo-d-Lactic Acid Fermentation from Arabinose by Redirection of the Phosphoketolase Pathway to the Pentose Phosphate Pathway in l-Lactate Dehydrogenase Gene-Deficient Lactobacillus plantarum

2009 ◽  
Vol 75 (15) ◽  
pp. 5175-5178 ◽  
Author(s):  
Kenji Okano ◽  
Shogo Yoshida ◽  
Tsutomu Tanaka ◽  
Chiaki Ogino ◽  
Hideki Fukuda ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactate Dehydrogenase ◽  
Lactobacillus Plantarum ◽  
Pentose Phosphate Pathway ◽  
Pentose Phosphate ◽  
Lactic Acid Fermentation ◽  
Acid Fermentation ◽  
Dehydrogenase Gene ◽  
Phosphoketolase Pathway ◽  
Optically Pure

ABSTRACT Optically pure d-lactic acid fermentation from arabinose was achieved by using the Lactobacillus plantarum NCIMB 8826 strain whose l-lactate dehydrogenase gene was deficient and whose phosphoketolase gene was substituted with a heterologous transketolase gene. After 27 h of fermentation, 38.6 g/liter of d-lactic acid was produced from 50 g/liter of arabinose.

Biochemical appraisal of a milk diluent for semen

1960 ◽  
Vol 54 (2) ◽  
pp. 166-169
Author(s):  
K. Friis Jakobsen ◽  
T. Mann
Keyword(s):  
Lactic Acid ◽  
Oxygen Uptake ◽  
Incubation Period ◽  
Milk Fat ◽  
Acid Production ◽  
Marked Effect ◽  
Lactic Acid Production ◽  
Milk Product ◽  
Bull Semen ◽  
Boar Spermatozoa

1. A study was made of the effects of a milk diluent on bull, ram and boar spermatozoa. Respiration and fructolysis of spermatozoa were used as the two main criteria of sperm activity. The milk diluent was a standardized and commercially available milk product, consisting of sterilized and homogenized milk, supplemented with milk fat.2. The rate of oxygen uptake measured manometrically in the presence of air was increased by the addition of the milk diluent throughout the entire incubation period. Fructose utilization was assessed by the rate of lactic-acid production. The rate of the anaerobic lactic-acid formation was higher in the presence of the milk diluent during the later stages of incubation.3. The effect of the milk diluent on sperm respiration was most striking in experiments with the sperm-rich portion of boar ejaculate obtained by fractionated collection. A somewhat less marked effect was observed with bull semen, and in ram semen the effect was comparatively weak.

Glucose oxidation in white adipose tissue from BIO 14.6 dystrophic hamsters

1986 ◽  
Vol 64 (10) ◽  
pp. 1321-1324
Author(s):  
J. Elbrink ◽  
E. G. Hunter
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Pentose Phosphate Pathway ◽  
Glucose Oxidation ◽  
Pentose Phosphate ◽  
Muscle Degeneration ◽  
Functional Integrity ◽  
Enhanced Activity ◽  
Retroperitoneal Adipose Tissue

In studies of glucose oxidation in white retroperitoneal adipose tissue of BIO 14.6 dystrophic and FIB normal hamsters aged 55–67 and 368–379 days, no difference was found in the basal state of radiolabelled 14CO2 production using either D-[6-14C]glucose or D-[1-14C]glucose. When C6-labelled glucose was used, insulin induced a slightly greater increase in glucose oxidation in dystrophic adipose tissue at both ages. When C1-labelled glucose was used, insulin enhanced glucose oxidation in dystrophic tissue more than twice normal in tissues from young animals and five times normal in tissues from the old ones. The increase in oxidation with D-[1-14C]glucose likely represents enhanced activity of the pentose phosphate pathway, which has also been observed in certain tissues of other animals with inherited skeletal-muscle degeneration. The change can probably be classified as being compensatory, an attempt by tissues to maintain functional integrity.

scholarly journals Isolation and Characterization of Acid-Tolerant, Thermophilic Bacteria for Effective Fermentation of Biomass-Derived Sugars to Lactic Acid

2006 ◽  
Vol 72 (5) ◽  
pp. 3228-3235 ◽  
Author(s):  
Milind A. Patel ◽  
Mark S. Ou ◽  
Roberta Harbrucker ◽  
Henry C. Aldrich ◽  
Marian L. Buszko ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Pentose Phosphate Pathway ◽  
Thermophilic Bacteria ◽  
Cellulase Activity ◽  
Pentose Phosphate ◽  
Bacterial Strains ◽  
16S Rrna Sequence ◽  
Cost Component ◽  
Isolation And Characterization ◽  
Fungal Cellulase

ABSTRACT Biomass-derived sugars, such as glucose, xylose, and other minor sugars, can be readily fermented to fuel ethanol and commodity chemicals by the appropriate microbes. Due to the differences in the optimum conditions for the activity of the fungal cellulases that are required for depolymerization of cellulose to fermentable sugars and the growth and fermentation characteristics of the current industrial microbes, simultaneous saccharification and fermentation (SSF) of cellulose is envisioned at conditions that are not optimal for the fungal cellulase activity, leading to a higher-than-required cost of cellulase in SSF. We have isolated bacterial strains that grew and fermented both glucose and xylose, major components of cellulose and hemicellulose, respectively, to l(+)-lactic acid at 50�C and pH 5.0, conditions that are also optimal for fungal cellulase activity. Xylose was metabolized by these new isolates through the pentose-phosphate pathway. As expected for the metabolism of xylose by the pentose-phosphate pathway, [13C]lactate accounted for more than 90% of the total 13C-labeled products from [13C]xylose. Based on fatty acid profile and 16S rRNA sequence, these isolates cluster with Bacillus coagulans, although the B. coagulans type strain, ATCC 7050, failed to utilize xylose as a carbon source. These new B. coagulans isolates have the potential to reduce the cost of SSF by minimizing the amount of fungal cellulases, a significant cost component in the use of biomass as a renewable resource, for the production of fuels and chemicals.

Pentose phosphate pathway in cellular trophoblasts from full-term human placentas

1991 ◽  
Vol 261 (6) ◽  
pp. C1042-C1047 ◽  
Author(s):  
A. J. Moe ◽  
D. R. Farmer ◽  
D. M. Nelson ◽  
C. H. Smith
Keyword(s):  
Amino Acids ◽  
Methylene Blue ◽  
Glucose Metabolism ◽  
Electron Acceptor ◽  
Pentose Phosphate Pathway ◽  
Cultured Cells ◽  
Minor Component ◽  
Pentose Phosphate ◽  
Full Term ◽  
A Minor

Glucose metabolism was investigated in cellular trophoblasts isolated from full-term human placentas. The specific yields of 14CO2 from D-[1-14C]glucose and D-[6-14C]glucose were used to determine glucose metabolism via the pentose cycle for cells freshly isolated or cells grown in culture for 1 and 3 days. Cells were mononucleated on day 1 but fused to form multinucleated syncytiotrophoblasts by day 3. The principal product of glucose metabolism under all conditions was lactate, accounting for approximately three-fourths of recovered 14C in products. Pentose cycle activity contributed 0.57 +/- 0.01, 0.39 +/- 0.06, and 0.21 +/- 0.05% of the glucose metabolized by cells freshly isolated, cultured for 1 day, and cultured for 3 days, respectively. In the presence of the electron acceptor methylene blue, pentose cycle activity increased to 16.5 +/- 2.1, 13.8 +/- 1.5, and 18.2 +/- 1.7% for cells freshly isolated, cultured for 1 day, and cultured for 3 days, respectively. Trace amounts of 14C were recovered in other products including amino acids and glycogen. These data suggest that pentose cycle activity in cellular trophoblasts from full-term placenta, like those in full-term villous tissue, is a minor component of glucose metabolism. However, these cultured cells maintain a capacity to oxidize glucose via the pentose cycle at relatively high rates.

Studies on the Biosynthesis of Mitomycin C by Streptomyces verticillatus

1971 ◽  
Vol 49 (8) ◽  
pp. 911-918 ◽  
Author(s):  
G. S. Bezanson ◽  
L. C. Vining
Keyword(s):  
Carbon Dioxide ◽  
Mitomycin C ◽  
Pentose Phosphate Pathway ◽  
Pentose Phosphate ◽  
Carbon Skeleton ◽  
Methyl Substituent ◽  
Methyl Group

Of a series of 14C-labeled substrates tested as precursors of mitomycin C, D-glucose was the most effective. L-Methionine-methyl-14C specifically labeled the methoxyl but not the C-methyl substituent; several precursors which labeled the carbamyl group were probably first metabolized to carbon dioxide. Other results suggest that the carbon skeleton of mitomycin is not assembled from an aromatic precursor derived by either the shikimate or polyketide pathways, and is not a disguised sesquiterpene. The distribution of radioactivity in C-6 and the attached methyl group of mitomycin C labeled from glucose-1-14C, -2-14C, and -6-14C is consistent with derivation of the methylbenzoquinone moiety from a seven-carbon intermediate which, in turn, originates from glucose by reactions of the nonoxidative pentose phosphate pathway. An additional molecule of glucose may supply the six remaining carbon atoms of the mitomycin C skeleton.

Metabolic activities of sheep erythrocytes. II. Formate metabolism

1962 ◽  
Vol 13 (1) ◽  
pp. 45 ◽  
Author(s):  
RA Leng ◽  
EF Annison
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Peroxide ◽  
Methylene Blue ◽  
Aerobic Oxidation ◽  
Carbon Dioxide Production ◽  
Anaerobic Conditions ◽  
Formate Oxidation ◽  
Metabolic Activities ◽  
Sulphydryl Compounds ◽  
Formate Metabolism

Whole sheep blood, washed erythrocytes, and haemolysates showed only a slight capacity to oxidize 14C-labelled formate, as measured by labelled carbon dioxide production. Considerable oxidation of formate by washed erythrocytes or haemolysates occurred in the presence of systems generating hydrogen peroxide enzymically or non-enzymically under aerobic conditions. In addition, methylene blue was found to stimulate markedly the aerobic oxidation of formate by erythrocytes and haemolysates, the effect being abolished under anaerobic conditions. The stimulatory effects of methylene blue and sulphydryl compounds were additive. Evidence was obtained that the effect of methylene blue was mediated through an enzyme which directly or indirectly gave rise to hydrogen peroxide, formate oxidation being achieved by a hydrogen peroxide-catalase complex. No evidence was obtained of formate incorporation into red cells.

The Effect of Washing on the Motility and Metabolism of Ram, Bull and Rabbit Spermatozoa

1953 ◽  
Vol 30 (2) ◽  
pp. 200-213
Author(s):  
I G. WHITE
Keyword(s):  
Lactic Acid ◽  
Oxygen Uptake ◽  
Acid Production ◽  
Bacterial Contamination ◽  
Aerobic Glycolysis ◽  
Lactic Acid Production ◽  
Total Oxygen ◽  
The Mean ◽  
Almost All ◽  
Rabbit Spermatozoa

1. The motility, oxygen uptake and aerobic glycolysis of unwashed, once- and twice-washed ram, bull and rabbit spermatozoa have been studied in a sodium phosphate-fructose diluent over a 5 hr. period at 37° C. 2. The mean ZO2 values obtained over the first hour for ram, bull and rabbit spermatozoa were 13.6, 13.3 and 7.1 respectively, and the corresponding mean total lactic acid production for each of these species over the 5 hr. period was 297, 439 and 413 µg./108 cells. Significant differences in oxygen uptake, lactic acid production and motility occurred between pooled ejaculates. 3. There was a decline in motility in almost all experiments, and a similar decline in oxygen consumption during the early hours. Towards the end of some experiments on unwashed ram and rabbit spermatozoa there was a rise in oxygen uptake which was shown to be due to bacterial contamination. 4. Washing once had no significant effect on motility, but washing twice adversely affected the motility of ram spermatozoa. 5. Significant decreases in total oxygen uptake occurred on washing ram spermatozoa twice and on washing rabbit spermatozoa both once and twice. This is believed to be due to the removal of bacteria. 6. Washing once had no significant effect on total lactic acid production, but it was significantly reduced on washing ram, bull and rabbit spermatozoa twice. This effect is believed to be associated with the spermatozoa themselves.

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