This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Taniai, H.
Right arrow Articles by Yoshida, S.-i.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Taniai, H.
Right arrow Articles by Yoshida, S.-i.
Right arrowPubmed/NCBI databases
*Substance via MeSH

 Previous Article  |  Next Article 

Journal of Bacteriology, May 2008, p. 3572-3579, Vol. 190, No. 10
0021-9193/08/$08.00+0     doi:10.1128/JB.01882-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Concerted Action of Lactate Oxidase and Pyruvate Oxidase in Aerobic Growth of Streptococcus pneumoniae: Role of Lactate as an Energy Source{triangledown}

Hiroaki Taniai,1,2* Ken-ichiro Iida,1 Masanori Seki,1 Mitsumasa Saito,1,3 Susumu Shiota,4 Hiroaki Nakayama,1 and Shin-ichi Yoshida1

Departments of Bacteriology,1 Environmental Medicine and Infectious Diseases,2 Pediatrics, Faculty of Medical Sciences,3 Department of Oral Health, Growth, and Development, Division of Oral Infectious Diseases and Immunology, Faculty of Dental Science, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan4

Received 30 November 2007/ Accepted 4 March 2008

Streptococcus pneumoniae was shown to possess lactate oxidase in addition to well-documented pyruvate oxidase. The activities of both H2O2-forming oxidases in wild-type cultures were detectable even in the early exponential phase of growth and attained the highest levels in the early stationary phase. For each of these oxidases, a defective mutant was constructed and compared to the parent regarding the dynamics of pyruvate and lactate in aerobic cultures. The results obtained indicated that the energy-yielding metabolism in the wild type could be best described by the following scheme. (i) As long as glucose is available, approximately one-fourth of the pyruvate formed is converted to acetate by the sequential action of pyruvate oxidase and acetate kinase with acquisition of additional ATP; (ii) the rest of the pyruvate is reduced by lactate dehydrogenase to form lactate, with partial achievement of redox balance; (iii) the lactate is oxidized by lactate oxidase back to pyruvate, which is converted to acetate as described above; and (iv) the sequential reactions mentioned above continue to occur as long as lactate is present. As predicted by this model, exogenously added lactate was shown to increase the final growth yield in the presence of both oxidases.

* Corresponding author. Mailing address: Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan. Phone: (81) 92 642 6130. Fax: (81) 92 642 6133. E-mail: taniai{at}bact.med.kyushu-u.ac.jp

{triangledown} Published ahead of print on 14 March 2008.

Journal of Bacteriology, May 2008, p. 3572-3579, Vol. 190, No. 10
0021-9193/08/$08.00+0     doi:10.1128/JB.01882-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»