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Saccharomycopsis fibuligera, which produces enzymes like amylase and protease as well as flavor substances like β-phenyl ethanol and phenyl acetate, plays a crucial role in traditional fermented foods. However, this strain still lacks a high-density fermentation culture, which has had an impact on the strain's industrial application process. Therefore, this study investigated the optimization of medium ingredients and fermentation conditions for high-density fermentation of S. fibuligera Y1402 through single-factor design, Plackett–Burman design, steepest ascent test, and response surface analysis. The study found that glucose at 360.61 g/L, peptone at 50 g/L, yeast extract at 14.65 g/L, KH2PO4 at 5.49 g/L, MgSO4 at 0.40 g/L, and CuSO4 at 0.01 g/L were the best medium ingredients for S. fibuligera Y1402. Under these conditions, after three days of fermentation, the total colony count reached 1.79 × 108 CFU/mL. The optimal fermentation conditions were determined to be an initial pH of 6.0, an inoculum size of 1.10%, a liquid volume of 12.5 mL/250 mL, a rotation speed of 120 r/min, a fermentation temperature of 21 °C and a fermentation time of 53.50 h. When fermentation was conducted using the optimized medium and conditions, the total colony count achieved a remarkable value of 5.50 × 109 CFU/mL, exhibiting a substantial increase of nearly 31 times the original value in the optimal culture medium. This significant advancement offers valuable insights and a reference for the industrial-scale production of S. fibuligera. [ABSTRACT FROM AUTHOR]

A high-yield 3-methylthiopropanol (3-Met) yeast Y1402 was obtained from sesame-flavored Daqu, and it was identified as Saccharomycopsis fibuligera. S. fibuligera Y1402 showed a broad range of growth temperatures and pH, as well as the maximum tolerance to glucose, NaCl, nicotine, and 3-Met at 50% (w/w), 15% (w/v), 1.2 g/L, and 18 g/L, respectively. After optimization using single-factor experiments, a Plackett–Burman design, a steepest ascent test, and a Box–Behnken design, the 3-Met yield reached 4.03 g/L by S. fibuligera Y1402 under the following optimal conditions: glucose concentration of 40 g/L, yeast extract concentration of 0.63 g/L, Tween 80 concentration of 2 g/L, L-methionine concentration of 5 g/L, liquid volume of 25 mL/250 mL, initial pH of 5.3, fermentation temperature of 32 °C, inoculum size of 0.8%, shaking speed of 210 rpm, and fermentation time of 54 h. The fermentation was scaled up to a 3 L fermenter under the optimized conditions, and the yield of 3-Met reached 0.71 g/L. Additionally, an aroma analysis revealed that the flavor substances produced by S. fibuligera Y1402 in sorghum hydrolysate medium was mainly composed of compounds with floral, sweet, creamy, roasted nut, and clove-like aromas. Therefore, S. fibuligera has great potential for application in the brewing of Baijiu and other fermented foods. [ABSTRACT FROM AUTHOR]

Fermented foods, which have emerged fortuitously over the course of human development, have become an essential part of human history worldwide. Third, researchers have explored the application of microorganisms in various stages of fermented food production, for example, in pre-treatment, fermentation, and post-fermentation processes. On the other hand, after 28 days of solid-state fermentation, the same actinomycete strains produced a total of 64 terpenoids using the five fermentation substrates, and the cumulative terpenoid content was determined to be 23,651.52 g/kg in the fermentation products. Despite the popularity of fermented foods globally, many traditional fermented foods are still produced using open fermentation methods where it is difficult to evaluate the safety or function of microorganisms, leading to inevitable challenges. [Extracted from the article]

This study optimized the fermentation conditions for producing glucanase from Burkholderia pyrrocinia B1213 using Jiuzao, a residue from Baijiu distillation, as the carbon source. The effects of Jiuzao particle size and concentration, type of nitrogen source, urea concentration, initial pH, inoculum size, loading volume, shaking speed, temperature, surfactant type and incubation time on glucanase production by B. pyrrocinia B1213 were investigated separately through single factor design. Then, five variables, Jiuzao concentration, inoculum size, initial pH, temperature and incubation time, were found to significantly affect glucanase production using the Plackett-Burman design. Following, the optimal conditions for glucanase production by B. pyrrocinia B1213 were found using the steepest ascent path and response surface methodology designs as: particle size, 40-60 mesh; Jiuzao concentration, 58.4 g/L; urea concentration, 8 g/L; initial pH, 6; loading volume, 15 mL/250 mL; inoculum size, 0.63% (v/v); temperature, 26 °C; shaking speed, 160 rpm; and incubation time, 120 h. Under these conditions, the glucanase activity of the B. pyrrcinia B1213 strain was 1336 U/mL, producing the biological enzymes needed in Baijiu making from a by-product. This study has provided experimental data and theoretical information for using B. pyrrcinia B1213 in Baijiu production. [ABSTRACT FROM AUTHOR]