Construction of industrial Saccharomyces cerevisiae strains for the efficient consolidated bioprocessing of raw starch
| dc.contributor.author | Cripwell, Rosemary A. | en_ZA |
| dc.contributor.author | Rose, Shaunita H. | en_ZA |
| dc.contributor.author | Favaro, Lorenzo | en_ZA |
| dc.contributor.author | Van Zyl, Willem H. | en_ZA |
| dc.date.accessioned | 2019-08-26T07:37:27Z | |
| dc.date.available | 2019-08-26T07:37:27Z | |
| dc.date.issued | 2019-08-20 | |
| dc.date.updated | 2019-08-25T03:28:33Z | |
| dc.description | CITATION: Cripwell, R. A., et al. 2019. Construction of industrial Saccharomyces cerevisiae strains for the efficient consolidated bioprocessing of raw starch. Biotechnology for Biofuels, 12:201, doi:10.1186/s13068-019-1541-5. | en_ZA |
| dc.description.abstract | Background: Consolidated bioprocessing (CBP) combines enzyme production, saccharification and fermentation into a one-step process. This strategy represents a promising alternative for economic ethanol production from starchy biomass with the use of amylolytic industrial yeast strains. Results: Recombinant Saccharomyces cerevisiae Y294 laboratory strains simultaneously expressing an α-amylase and glucoamylase gene were screened to identify the best enzyme combination for raw starch hydrolysis. The codon optimised Talaromyces emersonii glucoamylase encoding gene (temG_Opt) and the native T. emersonii α-amylase encoding gene (temA) were selected for expression in two industrial S. cerevisiae yeast strains, namely Ethanol Red™ (hereafter referred to as the ER) and M2n. Two δ-integration gene cassettes were constructed to allow for the simultaneous multiple integrations of the temG_Opt and temA genes into the yeasts’ genomes. During the fermentation of 200 g l−1 raw corn starch, the amylolytic industrial strains were able to ferment raw corn starch to ethanol in a single step with high ethanol yields. After 192 h at 30 °C, the S. cerevisiae ER T12 and M2n T1 strains (containing integrated temA and temG_Opt gene cassettes) produced 89.35 and 98.13 g l−1 ethanol, respectively, corresponding to estimated carbon conversions of 87 and 94%, respectively. The addition of a commercial granular starch enzyme cocktail in combination with the amylolytic yeast allowed for a 90% reduction in exogenous enzyme dosage, compared to the conventional simultaneous saccharification and fermentation (SSF) control experiment with the parental industrial host strains. Conclusions: A novel amylolytic enzyme combination has been produced by two industrial S. cerevisiae strains. These recombinant strains represent potential drop-in CBP yeast substitutes for the existing conventional and raw starch fermentation processes. | en_ZA |
| dc.description.uri | https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-019-1541-5 | |
| dc.description.version | Publisher's version | en_ZA |
| dc.format.extent | 16 pages : illustrations | en_ZA |
| dc.identifier.citation | Cripwell, R. A., et al. 2019. Construction of industrial Saccharomyces cerevisiae strains for the efficient consolidated bioprocessing of raw starch. Biotechnology for Biofuels, 12:201, doi:10.1186/s13068-019-1541-5 | en_ZA |
| dc.identifier.issn | 1754-6834 (online) | |
| dc.identifier.other | doi:10.1186/s13068-019-1541-5 | |
| dc.identifier.uri | http://hdl.handle.net/10019.1/106373 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.publisher | BMC (part of Springer Nature) | en_ZA |
| dc.rights.holder | Authors retain copyright | en_ZA |
| dc.subject | Bioethanol production | en_ZA |
| dc.subject | Ethanol production from starchy biomass | en_ZA |
| dc.subject | Saccharomyces cerevisiae strains | en_ZA |
| dc.subject | Conversion of starch to ethanol | en_ZA |
| dc.subject | Consolidated bioprocessing (CBP) | en_ZA |
| dc.title | Construction of industrial Saccharomyces cerevisiae strains for the efficient consolidated bioprocessing of raw starch | en_ZA |
| dc.type | Article | en_ZA |