Puxi Fan,Xuyu Liang,Yongtao Fei,Wenhong Zhao,Jinglong Liang,Weidong Bai,Songgui He
The distinct flavor of chi-flavor baijiu (CFB) has garnered significant attention in China. After the optimization of fermentation conditions,Pichia anomalaandLactobacillus plantarumwere introduced into the fermentation process to enhance the flavor. Samples inoculated with these mixed strains (SY) exhibited higher levels of alcohol (from 33.04 to 178.55 mg/L) and esters (from 49.51 to 130.20 mg/L) compared to the control group (KB). In SY,P. anomalaandL. plantarumwere the predominant microorganisms, whilePediococcusandSaccharomyceswere more prevalent in KB. Moreover, 68 volatile flavor compounds were detected in SY, as opposed to 64 in KB. Notably,Pichiashowed a positive correlation with key flavor compounds. The synergistic fermentation with exogenous strains led to a 52.38% increase in phenethyl alcohol and a 4.91% increase in ethyl lactate. Additionally, the levels of other flavor compounds, like ethyl acetate, γ-nonanolactone, and (E)-2-octenal, also increased. The results demonstrated that the addition ofP. anomalaandL. plantarumto the fermentation process of CFB significantly increased the contents of flavor compounds. This research reveals valuable insights into flavor enhancement and the microbial community dynamics in CFB production.
Yanru Chen,Yin Wan,Wenqin Cai,Xiaming Che,Xuehui Sun,Hong Peng,Huibo Luo,Dan Huang,Guiming Fu
Ethanol stress is an important environmental factor that affects physiological metabolism and aroma-producing capacity of yeast during the brewing process of alcoholic products. To explore the mechanisms of the growth and aroma-producing metabolism of Pichia anomala under ethanol stress, transcriptomic and metabolomic results were collected from different concentrations (3%, 6% and 9%) of the ethanol stressor, and genes, metabolites and metabolic pathways that relate to growth and aroma-producing were screened. Integrated transcriptomic and metabolomic results showed that P. anomala could respond to ethanol stress by activating purine and pyrimidine , glycerophospholipid and antioxidant metabolic pathways. However, the damage to the growth of P. anomala under ethanol stress was closely related to the inhibition of carbohydrate metabolism, ABC transporter , energy metabolism and amino acid pathways, the influence on these pathways became more serious with the increase of ethanol concentrations. Meantime, the decrease in production of phenethyl alcohol and isoamyl alcohol was related to the significantly down-regulated of ARO9 , ARO10 , ADH1 and ADH2 genes expression in phenylalanine , tyrosine and tryptophan , and glycolysis pathways of P. anomala under ethanol stress. The enhanced expression of ATF1 , EAT1 , EEB1 and TGL2 genes in P. anomala was the main reason for the high yield of ethyl caproate and ethyl acetate under ethanol stress. These results revealed a theoretical basis for further study of the effect mechanisms of ethanol stress on P. anomala and molecular targets for the construction of genetic engineering strains with high ethanol tolerance and high aroma production.
危险品化学品经营许可证（带存储）