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Bioethanol production from cassava starch using co-culture of saccharolytic molds with Saccharomyces cerevisiae TISTR 5088
Author(s)
Date Issued
August 1, 2024
Type
Article
Abstract
Cassava serves as a cornerstone for sustainable bioethanol production in Thailand. The cassava root is highly valuable, comprising 50–70% starch on a dry weight basis. Starch can be converted into fermentable sugars through chemical or biological methods. This study focused on harnessing the enzymatic potential of saccharolytic molds, specifically Aspergillus oryzae TISTR 3086 or Amylomyces rouxii TISTR 3182, to facilitate saccharification of cassava starch, followed by fermentation using Saccharomyces cerevisiae TISTR 5088 for bioethanol production. Among the various configurations, the co-culture of Amy. rouxii TISTR 3182 with S. cerevisiae TISTR 5088 was the most effective, resulting in the highest ethanol yield. This finding was observed for both the separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes. Impressively, the SSF approach to ethanol productivity demonstrated superior results with an ethanol concentration of 25.4±0.3 g/l and an ethanol productivity of 0.53 g/l/h (yield of 1.40 g/g reducing sugars), surpassing the SHF approach (25.4±0.7 g/l, an ethanol productivity of 0.26 g/l/h, yield of 0.57 g/g reducing sugars) while also reducing the fermentation period. Further investigations into optimizing the conditions for ethanol production were carried out using a co-culture of Amy. rouxii TISTR 3182 with S. cerevisiae TISTR 5088 during SSF. This exploration revealed that employing 100 g/l cassava starch and initiating fermentation with a medium pH of 6.0 led to the highest ethanol concentration at 48 h. This process showed potential for ethanol production, harnessing the synergistic action of saccharolytic molds alongside yeast.
Citation
Scienceasia, 50(4), 2024