Journal ArticleDOI
Galactose fermentation by Streptococcus lactis and Streptococcus cremoris: pathways, products, and regulation.
TLDR
All of the lactic streptococci examined except Streptococcus lactis ML8 fermented galactose to lactate, formate, acetate, and ethanol, and reduced intracellular levels of both the lactate dehydrogenase activator and pyruvate-formate lyase inhibitors appeared to be the main factors involved in the diversion of lactate to the other products.Abstract:
All of the lactic streptococci examined except Streptococcus lactis ML8 fermented galactose to lactate, formate, acetate, and ethanol. The levels of pyruvate-formate lyase and lactate dehydrogenase were elevated and reduced, respectively, in galactose-grown cells compared with glucose- or lactose-grown cells. Reduced intracellular levels of both the lactate dehydrogenase activator (fructose, 1,6-diphosphate) and pyruvate-formate lyase inhibitors (triose phosphates) appeared to be the main factors involved in the diversion of lactate to the other products. S. lactis ML8 produced only lactate from galactose, apparently due to the maintenance of high intracellular levels of fructose 1,6-diphosphate and triose phosphates. The growth rates of all 10 Streptococcus cremoris strains examined decreased markedly with galactose concentrations below about 30 mM. This effect appeared to be correlated with uptake predominantly by the low-affinity galactose phosphotransferase system and initial metabolism via the D-tagatose 6-phosphate pathway. In contrast, with four of the five S. lactis strains examined, galactose uptake and initial metabolism involved more extensive use of the high-affinity galactose permease and Leloir pathway. With these strains the relative flux of galactose through the alternate pathways would depend on the exogenous galactose concentration.read more
Citations
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OtherDOI
Lactic acid bacteria: classification and physiology.
TL;DR: The present taxonomy relies partly on true phylogenetic relationships, largely based on morphology, mode of glucose fermentation, growth at different temperatures, configuration of the lactic acid produced, ability to grow at high salt concentrations, and acid or alkaline tolerance.
Journal ArticleDOI
Factors affecting the fermentative lactic acid production from renewable resources1
TL;DR: Parameters affecting the fermentative lactic acid (LA) production are summarized and discussed: microorganism, carbon- and nitrogen-source, fermentation mode, pH, and temperature.
Journal ArticleDOI
Food fermentations: Microorganisms with technological beneficial use
F Bourdichon,Serge Casaregola,Choreh Farrokh,Jens Christian Frisvad,Monica L. Gerds,Walter P. Hammes,James Harnett,Geert Huys,Svend Laulund,Arthur C. Ouwehand,Ian B. Powell,Jashbhai B. Prajapati,Yasuyuki Seto,Eelko Ter Schure,Aart Van Boven,Vanessa Vankerckhoven,Annabelle Zgoda,Sandra Tuijtelaars,Egon Bech Hansen +18 more
TL;DR: An updated inventory of microorganisms used in food fermentations covering a wide range of food matrices and the taxonomy is reviewed and updated in order to bring theTaxonomy in agreement with the current standing in nomenclature.
Journal ArticleDOI
Responses of lactic acid bacteria to oxygen
TL;DR: Lactic acid bacteria exhibit an inducible oxidative stress response when exposed to sublethal levels of H2O2, and this response protects them if they are subsequently exposed to lethal concentrations of H 2O2.
Journal ArticleDOI
Control of the shift from homolactic acid to mixed-acid fermentation in Lactococcus lactis: predominant role of the NADH/NAD+ ratio.
TL;DR: During batch growth of Lactococcus lactis subsp.
References
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Journal ArticleDOI
Determination of protein: A modification of the lowry method that gives a linear photometric response
TL;DR: Under the new conditions there is direct proportionality between absorbance at 650 nm and weight of protein within the range 15–110 μg.
Journal ArticleDOI
A specific micromethod for the determination of acyl phosphates
TL;DR: In this communication, a method is described which utilizes the reaction of acyl phosphates with hydroxylamine and the acyl part of the acid anhydride is converted into hydroxamic acid.
Journal ArticleDOI
Change from Homo- to Heterolactic Fermentation by Streptococcus lactis Resulting from Glucose Limitation in Anaerobic Chemostat Cultures
TL;DR: Lactic streptococci, classically regarded as homolactic fermenters of glucose and lactose, became heterolactic when grown with limiting carbohydrate concentrations in a chemostat, indicating that fine control of enzyme activity is an important factor in the fermentation change.