Journal of Fungi (Jul 2021)

Bioethanol Production from Cellulose-Rich Corncob Residue by the Thermotolerant <i>Saccharomyces cerevisiae</i> TC-5

  • Pinpanit Boonchuay,
  • Charin Techapun,
  • Noppol Leksawasdi,
  • Phisit Seesuriyachan,
  • Prasert Hanmoungjai,
  • Masanori Watanabe,
  • Siraprapa Srisupa,
  • Thanongsak Chaiyaso

DOI
https://doi.org/10.3390/jof7070547
Journal volume & issue
Vol. 7, no. 7
p. 547

Abstract

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This study aimed to select thermotolerant yeast for bioethanol production from cellulose-rich corncob (CRC) residue. An effective yeast strain was identified as Saccharomyces cerevisiae TC-5. Bioethanol production from CRC residue via separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and prehydrolysis-SSF (pre-SSF) using this strain were examined at 35–42 °C compared with the use of commercial S. cerevisiae. Temperatures up to 40 °C did not affect ethanol production by TC-5. The ethanol concentration obtained via the commercial S. cerevisiae decreased with increasing temperatures. The highest bioethanol concentrations obtained via SHF, SSF, and pre-SSF at 35–40 °C of strain TC-5 were not significantly different (20.13–21.64 g/L). The SSF process, with the highest ethanol productivity (0.291 g/L/h), was chosen to study the effect of solid loading at 40 °C. A CRC level of 12.5% (w/v) via fed-batch SSF resulted in the highest ethanol concentrations of 38.23 g/L. Thereafter, bioethanol production via fed-batch SSF with 12.5% (w/v) CRC was performed in 5-L bioreactor. The maximum ethanol concentration and ethanol productivity values were 31.96 g/L and 0.222 g/L/h, respectively. The thermotolerant S. cerevisiae TC-5 is promising yeast for bioethanol production under elevated temperatures via SSF and the use of second-generation substrates.

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