Bioprocess and Biosystems Engineering

, Volume 35, Issue 1, pp 183–189

Reduction of PDC1 expression in S. cerevisiae with xylose isomerase on xylose medium

Authors

  • Dong Min Kim
    • BK21 Ubiquitous Information AppliancesChonnam National University
  • Seung-Hyun Choi
    • Department of Biological SciencesChonnam National University
  • Byung Sam Ko
    • Department of Biological SciencesChonnam National University
  • Gwon-Young Jeong
    • Department of Biological SciencesChonnam National University
  • Han-Bit Jang
    • Department of Biological SciencesChonnam National University
  • Jae-Gun Han
    • College of Bioscience and BiotechnologyKangwon National University
  • Kyung-Hwan Jeong
    • Department of BiotechnologyChungju National University
  • Hyeon-Yong Lee
    • College of Bioscience and BiotechnologyKangwon National University
    • BK21 Ubiquitous Information AppliancesChonnam National University
    • Department of Biological SciencesChonnam National University
Original Paper

DOI: 10.1007/s00449-011-0638-4

Cite this article as:
Kim, D.M., Choi, S., Ko, B.S. et al. Bioprocess Biosyst Eng (2012) 35: 183. doi:10.1007/s00449-011-0638-4

Abstract

Ethanol production using hemicelluloses has recently become a focus of many researchers. In order to promote d-xylose fermentation, we cloned the bacterial xylA gene encoding for xylose isomerase with 434 amino acid residues from Agrobacterium tumefaciens, and successfully expressed it in Saccharomyces cerevisiae, a non-xylose assimilating yeast. The recombinant strain S. cerevisiae W303-1A/pAGROXI successfully colonized a minimal medium containing d-xylose as a sole carbon source and was capable of growth in minimal medium containing 2% xylose via aerobic shake cultivation. Although the recombinant strain assimilates d-xylose, its ethanol productivity is quite low during fermentation with d-xylose alone. In order to ascertain the key enzyme in ethanol production from d-xylose, we checked the expression levels of the gene clusters involved in the xylose assimilating pathway. Among the genes classified into four groups by their expression patterns, the mRNA level of pyruvate decarboxylase (PDC1) was reduced dramatically in xylose media. This reduced expression of PDC1, an enzyme which converts pyruvate to acetaldehyde, may cause low ethanol productivity in xylose medium. Thus, the enhancement of PDC1 gene expression may provide us with a useful tool for the fermentation of ethanol from hemicellulose.

Keywords

EthanolPyruvate carboxylaseSaccharomyces cerevisiaeXyloseXylose isomerase

Copyright information

© Springer-Verlag 2011