Abstract
Lactate dehydrogenase (LDH) was purified from three strains of Streptococcus bovis, and the gene ldh was cloned and sequenced. The ldh of S. bovis from a goat (TH1) was different from the ldhs of two other strains from cattle (TH2, JB1) in that Asp(220) was substituted for Glu. Northern blot analysis revealed that the LDH-mRNA of S. bovis was approximately 1.0 kbp, which was transcribed in a monocistronic fashion. When cells were grown at pH 6.9 in a batch culture, the level of ldh transcript decreased as the growth phase changed; from exponential growth to the cessation of growth. The level of ldh transcript was higher in cells grown at pH 4.5 than at pH 6.9. This observation was consistent with the amounts of LDH in cells and the percentages of lactate produced. These results support the hypothesis that S. bovis regulates LDH synthesis at the transcriptional level probably in response to intracellular pH.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
