Identification of Core Regulatory Genes and Metabolic Pathways for the n-Propanol Synthesis in Saccharomyces cerevisiae

The n-propanol produced by Saccharomyces cerevisiae has a remarkable effect on the taste and flavor of Chinese Baijiu. The n-propanol metabolism-related genes were deleted to evaluate the role in the synthesis of n-propanol to ascertain the key genes and pathways for the production of n-propanol by S. cerevisiae. The results showed that CYS3, GLY1, ALD6, PDC1, ADH5, and YML082W were the key genes affecting the n-propanol metabolism in yeast. The n-propanol concentrations of alpha 5 Delta GLY1, alpha 5 Delta CYS3, and alpha 5 Delta ALD6 increased by 121.75, 22.75, and 17.78%, respectively, compared with alpha 5. The n-propanol content of alpha 5 Delta PDC1, alpha 5 Delta ADH5, and alpha 5 Delta YML082W decreased by 24.98, 8.35, and 8.44%, respectively, compared with alpha 5. The contents of intermediate metabolites were measured, and results showed that the mutual transformation of glycine and threonine in the threonine pathway and the formation of propanal from 2-ketobutyrate were the core pathways for the formation of n-propanol. Additionally, YML082W played important role in the synthesis of n-propanol by directly producing 2-ketobutyric acid through L-homoserine. This study provided valuable insights into the n-propanol synthesis in S. cerevisiae and the theoretical basis for future optimization of yeast strains in Baijiu making.

Automated summary

This study identified key genes and pathways for the production of n-propanol by S. cerevisiae by deleting n-propanol metabolism-related genes. It revealed that glycine and threonine transformation and the formation of propanal from 2-ketobutyrate were core pathways for n-propanol synthesis, with YML082W playing an important role in directly producing 2-ketobutyric acid. The findings provide valuable insights for future optimization of yeast strains in Baijiu making.