Collagen Peptide Provides Saccharomyces cerevisiae with Robust Stress Tolerance for Enhanced Bioethanol Production

Efficient production of bioethanol is desirable for bioenergy large-scale applications, but it is severely challenged by ethanol and sugar stresses. Here, collagen peptide (CP), as a renewable nitrogen-containing biomass, remarkably enhanced the stress resistance of Saccharomyces cerevisiae SLL-510 against ethanol challenge, based on its unique amino acid composition. Transcriptome analysis showed that the energy, lipid, cofactor, and vitamin metabolism may involve in stress tolerance provided by CP. When CP was added into the media containing 249.99 mg/mL glucose, the bioethanol yield increased from 8.03 to 12.25% (v/v) and 11.35 to 12.29% (v/v) at 43 and 120 h, respectively. Moreover, at 286.79 mg/mL glucose, the highest yield reached 14.48% (v/v), with 99.58% glucose utilization rate. The protection and promotion effects of CP were also shown by four other industrial S. cerevisiae strains. These results coupled with the advantages of abundant reserves, cleanliness, and renewability revealed that CP is a promising economically viable and industrially scalable enhancer for bioethanol fermentation.