Ethanol production from non-detoxified hardwood spent sulfite liquor in submerged fed-batch culture using advanced yeasts

Autor: Niel Bezuidenhout, Daneal C. S. Rorke, Eugéne van Rensburg, Danie Diedericks, Johann F. Görgens
Rok vydání: 2023
Předmět:
Zdroj: Biomass Conversion and Biorefinery.
ISSN: 2190-6823
2190-6815
DOI: 10.1007/s13399-023-03992-6
Popis: To improve process feasibility, it is essential to use hardwood spent sulfite liquor (HSSL) as the main feedstock for bioethanol production, without prior detoxification. In addition, operating at large-scale under cost-effective conditions such as a small inoculum size (Saccharomyces cerevisiae strains, CelluX™4 and TFA7, was assessed. The inhibitory effect of non-detoxified HSSL was mitigated, and the ethanol titer increased from 4.1 to 7.9 g/L when pulse fed-batch was used instead of batch production, with CelluX™4 performing best. Both strains made use of the xylose isomerase (XI) pathway, with strain TFA7 engineered for increased tolerance against inhibitors. By administering concentrated HSSL in pulses to shake-flask cultures, the ethanol titer could be increased by approximately 50–90% when compared to simple batch cultures supplemented with 20%, 40%, and 60% (v/v) dilutions of HSSL. CelluX™4 was used in non-aerated, non-sterile 5-L bioreactor fermentations with a low cell concentration (S. cerevisiae strain, CelluX™4, combined with a fed-batch strategy, offers an inexpensive and straightforward process with real upscaling potential for industrial HSSL fermentations.
Databáze: OpenAIRE
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