Abstract (Expand)
Several lactic acid bacteria use homolactic fermentation for generation of ATP. Here we studied the role of the lactate dehydrogenase enzyme on the general physiology of the three homolactic acid … bacteria Lactococcus lactis, Enterococcus faecalis and Streptococcus pyogenes. Of note, deletion of the ldh genes hardly affected the growth rate in chemically defined medium in microaerophilic conditions. However, growth rate was affected in rich medium. Furthermore, deletion of ldh affected the ability for utilization of various substrates as a carbon source. A switch to mixed acid fermentation was observed in glucose-limited continuous growth and was dependent on the growth rate for S. pyogenes and dependent on the pH for E. faecalis. In S. pyogenes and L. lactis a change in pH resulted in a clear change in Yatp. The pH that showed the highest Yatp corresponded to the pH of the natural habitat of the organisms.
Authors: , , , , Anja Pritzschke, Nikolai Siemens, , ,
Date Published: 25th Nov 2010
Publication Type: Not specified
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