title: The effect of lactic acid on anaerobic carbon or nitrogen limited chemostat cultures of Saccharomyces cerevisiae.
abstract: Weak organic acids are well-known metabolic effectors in yeast and other micro-organisms. High concentrations of lactic acid due to infection of lactic acid bacteria often occurs in combination with growth under nutrient-limiting conditions in industrial yeast fermentations. The effects of lactic acid on growth and product formation of Saccharomyces cerevisiae were studied, with cells growing under carbon- or nitrogen-limiting conditions in anaerobic chemostat cultures (D=0.1 h(-1)) at pH values 3.25 and 5. It was shown that lactic acid in industrially relevant concentrations had a rather limited effect on the metabolism of S. cerevisiae. However, there was an effect on the energetic status of the cells, i.e. lactic acid addition provoked a reduction in the adenosine triphosphate (ATP) content of the cells. The decrease in ATP was not accompanied by a significant increase in the adenosine monophosphate levels.
authors.affiliation: Department of Chemistry and Bioscience, Molecular Biotechnology, Lundberg Laboratory, Chalmers University of Technology, Box 462, 405 30, Gothenburg, Sweden. elisabeth.thomsson@chembio.chalmers.se
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Thomsson
authors.forename: Christer
authors.initials: C
authors.lastname: Larsson
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000693:Anaerobiosis; D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism; D007218:Industrial Microbiology / Q000379:methods*; D019344:Lactic Acid / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000254:growth & development* / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; D019344:Lactic Acid; D000431:Ethanol; D002244:Carbon; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D005947:Glucose; D009584:Nitrogen; D005990:Glycerol