Proteomic analysis of Saccharomyces cerevisiae under high gravity fermentation conditions.
Saccharomyces cerevisiae KAY446 was utilized for ethanol production, with glucose concentrations ranging from 120 g/L (normal) to 300 g/L (high). Although grown in a high glucose environment, S. cerevisiae still retained the ability to produce ethanol with a high degree of glucose utilization. iTRAQ-mediated shotgun proteomics was applied to identify relative expression change of proteins under the different glucose conditions. A total of 413 proteins were identified from three replicate, independent LC-MS/MS runs. Unsurprisingly, many proteins in the glycolysis/gluconeogenesis pathway showed significant changes in expression level. Twenty five proteins involved in amino acid metabolism decreased their expression, while the expressions of 12 heat-shock related proteins were also identified. Under high glucose conditions, ethanol was produced as a major product. However, the assimilation of glucose as well as a number of byproducts was also enhanced. Therefore, to optimize the ethanol production under very high gravity conditions, a number of pathways will need to be deactivated, while still maintaining the correct cellular redox or osmotic state. Proteomics is demonstrated here as a tool to aid in this forward metabolic engineering.
Pham
Trong Khoa
TK
Biological and Environmental Systems Group, Department of Chemical and Process Engineering, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK.
Chong
Poh Kuan
PK
Gan
Chee Sian
CS
Wright
Phillip C
PC
D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D005947:Glucose; D006019:Glycolysis / Q000235:genetics*; D018471:Hypergravity; D013058:Mass Spectrometry; D040901:Proteomics; D012441:Saccharomyces cerevisiae
D005656:Fungal Proteins; D000431:Ethanol; D005947:Glucose