Endonuclease α from Saccharomyces cerevisiae shows increased activity on ultraviolet irradiated native DNA

1978 ◽  
Vol 167 (2) ◽  
pp. 139-145 ◽  
Author(s):  
Douglas W. Bryant ◽  
Robert H. Haynes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Increased Activity

scholarly journals Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae

2009 ◽  
Vol 75 (8) ◽  
pp. 2320-2325 ◽  
Author(s):  
Derek A. Abbott ◽  
Erwin Suir ◽  
Giang-Huong Duong ◽  
Erik de Hulster ◽  
Jack T. Pronk ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Reference Strain ◽  
Specific Growth ◽  
Pyruvate Decarboxylase ◽  
Additional Stress ◽  
Batch Cultures ◽  
Native Promoter ◽  
Specific Growth Rates ◽  
Increased Activity

ABSTRACT Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2Δ reference strain, used to avoid aerobic consumption of lactic acid, had a specific growth rate of 0.25 h−1 in anaerobic batch cultures containing lactic acid but only 0.16 h−1 in identical aerobic cultures. Measurements of aerobic cultures of S. cerevisiae showed that the addition of lactic acid to the growth medium resulted in elevated levels of reactive oxygen species (ROS). To reduce the accumulation of lactic acid-induced ROS, cytosolic catalase (CTT1) was overexpressed by replacing the native promoter with the strong constitutive TPI1 promoter. Increased activity of catalase was confirmed and later correlated with decreased levels of ROS and increased specific growth rates in the presence of high lactic acid concentrations. The increased fitness of this genetically modified strain demonstrates the successful attenuation of additional stress that is derived from aerobic metabolism and may provide the basis for enhanced (micro)aerobic production of organic acids in S. cerevisiae.

Increased Activity of Wall Hydrolytic Enzymes May Explain the Phenotype of Saccharomyces cerevisiae Fragile Mutants

1998 ◽  
Vol 37 (6) ◽  
pp. 365-367 ◽  
Author(s):  
José Ruiz-Herrera ◽  
Claudia León-Ramírez ◽  
P. Elizabeth Alvarez ◽  
Pencho Venkov
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Hydrolytic Enzymes ◽  
Increased Activity

Activation of chitin synthetase in permeabilized cells of a Saccharomyces cerevisiae mutant lacking proteinase B

1982 ◽  
Vol 152 (3) ◽  
pp. 1255-1264
Author(s):  
M P Fernandez ◽  
J U Correa ◽  
E Cabib
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chelating Agent ◽  
Metal Chelators ◽  
Trypsin Treatment ◽  
Permeabilized Cells ◽  
Chitin Synthetase ◽  
Activity Curve ◽  
Subsequent Step ◽  
Increased Activity

Digitonin treatment at 30 degrees C of a Saccharomyces cerevisiae mutant lacking proteinase B permeabilized the cells and caused rapid and extensive activation of chitin synthetase in situ. The same result was obtained with a mutant generally defective in vacuolar proteases. By lowering the temperature and using different permeabilization procedures, we showed that increases in permeability and activation are distinct processes. Activation was inhibited by the protease inhibitors antipain and leupeptin, but by pepstatin or chymostatin. Metal chelators were also inhibitory, and their effect was reversed by the addition of Ca2+ but not by Mg2+. Antipain added together with Ca2+ after incubation of the cells in the presence of a chelating agent prevented reversal of inhibition, a result that was interpreted as indicating that antipain acts either on the same step affected by Ca2+ or on a subsequent step. Efforts to obtain activation in cell-free extracts were unsuccessful, but it was possible to extract the synthetase, once activated, by breaking permeabilized cells with glass beads. Treatment of the cell-free extracts with trypsin led not only to increased activity of chitin synthetase, but also to a change in the pH-activity curve and a diminished requirement by the enzyme for free N-acetylglucosamine. These observations suggest that the modification undergone by the synthetase during endogenous activation is different from that brought about by trypsin treatment.

Anti-Saccharomyces cerevisiae Antibodies in Inflammatory Bowel Disease: a Family Study

2001 ◽  
Vol 36 (2) ◽  
pp. 196-201 ◽  
Author(s):  
F. Seibold ◽  
O. Stich ◽  
R. Hufnagl ◽  
S. Kamil ◽  
M. Scheurlen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Family Study ◽  
Inflammatory Bowel
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