Potentials of multi-stress tolerant yeasts, Saccharomyces cerevisiae and Pichia kudriavzevii for fuel ethanol production from industrial cassava wastes. (December 2021)

• Record Type: Journal Article
• Authors: Murata, Yoshinori; Nwuche, Charles O.; Nweze, Julius E.; Ndubuisi, Ifeanyi A.; Ogbonna, James C.
• Is Part Of: Process biochemistry. Volume 111:Part 2(2021)
• Page Start: 305
• Page End: 314
• Publication Date: 2021-12
• Subjects: Industrial wastes -- Bioethanol production -- Fermentation yeasts -- Multi-stress tolerance -- Cyanide inhibition -- Detergent inhibition; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2021.11.014
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Bioethanol production from cassava peels and pulps under multiple stress condition by newly isolated tolerant yeasts, Saccharomyces cerevisiae LC 269108 and Pichia kudriavzevii LC375240. Highlights: Industrial cassava pulp contains detergents and other inhibitory substances. Cyanide and detergent inhibition site is on pyruvate synthetic pathway. S. cerevisiae LC269108 efficiently fermented cassava peel containing cyanide at 40 °C. P. kudriavzevii LC375240 could ferment cassava pulp containing detergent at 40 °C. Co-culture of the isolates improved ethanol production from cassava peels. Abstract: Cassava processing wastes are suitable substrates for bioethanol production due to their high starch contents. However, these cassava wastes often contain various substances that inhibit cell growth and ethanol production. The abilities of multi-stress tolerant Saccharomyces cerevisiae LC269108 and Pichia kudriavzevii LC375240 to produce ethanol from cassava industrial wastes were evaluated. Analysis of cassava peels and pulps from two cassava starch factories showed that the cassava peels contained high cyanide (KCN) concentrations while cassava pulps contained high concentrations of sodium dodecyl benzene sulfonate (SDBS) used to improve starch extraction in the factory. Although S. cerevisiae LC269108 produced ethanol efficiently from the cassava peel, its growth and ethanol production were inhibited in the cassava pulp. On the other hand, the growth and ethanol production by P. kudriavzevii LC375240 were inhibited slightly in the cassava peel but not in the cassava pulp. Based on the intracellular pyruvate concentrations in the presence of KCN and SDBS, it was inferred that their inhibition site is on the pyruvate synthetic pathways. With a co-culture of the two strains, ethanol production from the cassava peel increased significantly but there was no significant improvement in ethanol production from the cassava pulp.