title: Contribution of the tricarboxylic acid (TCA) cycle and the glyoxylate shunt in Saccharomyces cerevisiae to succinic acid production during dough fermentation.
abstract: Succinic acid produced by yeast during bread dough fermentation can significantly affect the rheological properties of the dough. By introducing mutations in the model S288C yeast strain, we show that the oxidative pathway of the TCA cycle and the glyoxylate shunt contribute significantly to succinic acid production during dough fermentation. More specifically, deletion of ACO1 and double deletion of ACO1 and ICL1 resulted in a 36 and 77% decrease in succinic acid levels in fermented dough, respectively. Similarly, double deletion of IDH1 and IDP1 decreased succinic acid production by 85%, while also affecting the fermentation rate. By contrast, double deletion of SDH1 and SDH2 resulted in a two-fold higher succinic acid accumulation compared to the wild-type. Deletion of fumarate reductase activity (FRD1 and OSM1) in the reductive pathway of the TCA cycle did not affect the fermentation rate and succinic acid production. The changes in the levels of succinic acid produced by mutants Δidh1Δidp1 (low level) and Δsdh1Δsdh2 (high level) in fermented dough only resulted in small pH differences, reflecting the buffering capacity of dough at a pH of around 5.1. Moreover, Rheofermentometer analysis using these mutants revealed no difference in maximum dough height and gas retention capacity with the dough prepared with S288C. The impact of the changed succinic acid profile on the organoleptic or antimicrobial properties of bread remains to be demonstrated.
authors.affiliation: Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
authors.forename: Mohammad N
authors.initials: MN
authors.lastname: Rezaei
authors.affiliation: VIB Laboratory for Systems Biology & CMPG Laboratory for Genetics and Genomics, KU Leuven, Bio-Incubator, Gaston Geenslaan 1, B-3001 Heverlee, Belgium.
authors.forename: Elham
authors.initials: E
authors.lastname: Aslankoohi
authors.affiliation: VIB Laboratory for Systems Biology & CMPG Laboratory for Genetics and Genomics, KU Leuven, Bio-Incubator, Gaston Geenslaan 1, B-3001 Heverlee, Belgium.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Verstrepen
authors.affiliation: Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium. Electronic address: christophe.courtin@biw.kuleuven.be.
authors.forename: Christophe M
authors.initials: CM
authors.lastname: Courtin
mesh_terms: D019149:Bioreactors; D001939:Bread / Q000382:microbiology*; D002952:Citric Acid Cycle / Q000502:physiology*; D005285:Fermentation / Q000502:physiology*; D017353:Gene Deletion; D006038:Glyoxylates / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D013385:Succinate Dehydrogenase / Q000235:genetics; D019802:Succinic Acid / Q000378:metabolism
chemical_list: D006038:Glyoxylates; C063916:OSM1 protein, S cerevisiae; C528541:SDH1 protein, S cerevisiae; C541941:SDH2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D019802:Succinic Acid; D013385:Succinate Dehydrogenase; C031150:glyoxylic acid
keywords: Dough fermentation; Glyoxylate shunt; Rheology; Saccharomyces cerevisiae; Succinic acid; TCA cycle