Glucose metabolism in Lactococcus lactis MG1363 under different aeration conditions: requirement of acetate to sustain growth under microaerobic conditions

Appl Environ Microbiol. 2003 Jun;69(6):3462-8. doi: 10.1128/AEM.69.6.3462-3468.2003.


Lactococcus lactis subsp. lactis MG1363 was grown in batch cultures on a defined medium with glucose as the energy source under different aeration conditions, namely, anaerobic conditions, aerobic conditions, and microaerobic conditions with a dissolved oxygen tension of 5% (when saturation with air was used as the reference). The maximum specific growth rate was high (0.78 to 0.91 h(-1)) under all aeration conditions but decreased with increasing aeration, and more than 90% of the glucose was converted to lactate. However, a shift in by-product formation was observed. Increasing aeration resulted in acetate, CO(2), and acetoin replacing formate and ethanol as end products. Under microaerobic conditions, growth came to a gradual halt, although more than 60% of the glucose was still left. A decline in growth was not observed during microaerobic cultivation when acetate was added to the medium. We hypothesize that the decline in growth was due to a lack of acetyl coenzyme A (acetyl-CoA) needed for fatty acid synthesis since acetyl-CoA can be synthesized from acetate by means of acetate kinase and phosphotransacetylase activities.

MeSH terms

  • Acetates / metabolism
  • Aerobiosis
  • Anaerobiosis
  • Biomass
  • Culture Media
  • Glucose / metabolism*
  • Lactococcus lactis / enzymology
  • Lactococcus lactis / growth & development*
  • Lactococcus lactis / metabolism


  • Acetates
  • Culture Media
  • Glucose