Microorganisms
·
2024
·Vol. 13
·期 1
·22
·
IF 4.1
Hyun-Jin Kang,Hwan Hee Yu,Chang-Won Cho,Young Kyung Rhee,Tae-Wan Kim,Young-Wook Chin
Yeast formulations such as dry yeast are essential for supplying microbial starters to the alcoholic beverage industry. In Korea, the expensive freeze-drying method is used to manufacture brewer’s dry yeast, and therefore an economical process such as fluidized bed drying is needed. In the dry yeast manufacturing process, the medium and drying conditions are key factors that determine its quality and manufacturing cost. In this study, we aimed to optimize the medium composition and fluidized bed drying conditions for the efficient production of dry yeast. Muscovado and corn steep liquor were used as the carbon and nitrogen sources, respectively, and their optimal concentrations were identified using response surface methodology for efficient cultivation ofSaccharomyces cerevisiaeReY4-7 isolated fromnuruk. Central composite design analysis revealed that the optimal medium composition was 146.12 g/L muscovado and 58.68 g/L corn steep liquor. A dry cell weight of 36 g/L was achieved during 24 h of batch fermentation in a 30-L bioreactor containing this medium. Analysis of protective agents against fluidized bed drying revealed Span 80 as the strongest protective agent forS. cerevisiaeReY4-7. Response surface methodology revealed 50 °C and 41.45 min as the optimal fluidized bed drying conditions, under which the viable cell count reached 10.28 log CFU/g, comparable to that of the commercial dry yeast products. Overall, optimization of the medium and drying conditions significantly improved the final cell concentration in the cultivation process and the viable cell count in the drying process of dry yeast.
研究领域:
生物工程
·
食品科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF DAIRY SCIENCE
·
2025
·
IF 4.4
Huixin Dong,Xintong Zhang,Shuaishuai Li,Jingbo Ma,Jun Zhang,Hongyang Chen,Yudith lamothe Crespo,Junhu Yao,Zongjun Li
The objective of the current study was to evaluate the short-term effects of fumarate and active dry yeast (ADY) on ruminal fermentation, methane (CH 4 ) emissions, microbiota (composition and function), apparent total-tract digestibility, production performance, and blood metabolites in dairy goats using a 2 × 2 factorial design. Twenty-eight primiparous dairy goats were blocked and randomly assigned to 1 of 4 treatments: (1) control; (2) fumarate supplied at 34 g/d; (3) ADY supplied at 1.5 g/d; and (4) fumarate and ADY supplied in combination. The treatments lasted for 38 d. The results showed that fumarate supplementation reduced CH 4 production (L/d), yield (L/kg DMI), and intensity (L/kg milk yield) by 11.3%, 15.5%, and 21.9%, respectively, without affecting DMI, milk yield, or apparent nutrient digestibility. However, the CH 4 -depressing effect of fumarate began to decline 3 h postprandially and gradually diminished thereafter. Additionally, fumarate supplementation increased FCM with a higher NE L while reducing the ADG of goats with a lower NE G , resulting in no overall change in the net energy available for production. Fumarate supplementation also increased ruminal pH but reduced total VFA concentrations and microbial α diversity. Although fumarate did not alter the ruminal microbial structure at the genome or gene level, it stimulated the growth of fumarate- and lactate-utilizing bacteria, which may contribute to CH 4 mitigation and raise rumen pH. Supplementation with ADY increased the NE L and the molar proportion of ruminal butyrate and tended to increase CH 4 production and FCM without affecting CH 4 yield or intensity. Most of the blood metabolites and enzymes influenced by fumarate were involved in the tricarboxylic acid (TCA) and the urea cycles. Fumarate reduced the substrate concentrations of the TCA cycle (e.g., glucose, malondialdehyde) and the urea cycle (e.g., ammonia) in blood, but it increased the end products of the urea cycle (BUN, MUN) and enhanced the activity of malate dehydrogenase, a key enzyme in the TCA cycle. These findings indicate that fumarate can reduce enteric CH 4 emissions and enhance the TCA and the urea cycles in host animals.
研究领域:
畜牧学
·
反刍动物营养
·
甲烷减排
·
微生物学
·
代谢组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2022
·
IF 5.318
Yaling Huang,Junwen Wan,Min Sun,Tao Feng,Qian Liu,Shiqing Song,Xiaoming Zhang,Chi-Tang Ho
The sensomics approach was applied to elucidate the flavor profile of Chinese steamed breads (CSBs) fermented by different fresh and dry yeast, respectively. The quantitative descriptive analysis (QDA) led to the establishment of seven sensory attributes. Results noted that fresh yeast CSBs were characterized by milk, bouquet, sweet, and sour attributes, while the corresponding dry yeast CSBs exhibited wheat and yeast attributes. According to OAVs ≥1, 34 aroma-active chemicals were shown to be significant odorants. Isoamyl alcohol, 2,3-butanediol, benzoic acid , acetoin, hexanal, and indole had a significant contribution to the different aroma profiles of dry and fresh yeast CSBs. The result of correlation analysis showed that 2,3-butanediol and benzoic acid were correlated with sweet, milk, and sour attributes, hexanal and indole were related to bouquet attribute, and acetoin was associated with flour. Further aroma recombination confirmed the contribution of these key components in flavor discrimination of CSBs. These results will provide guidance for the yeast-CSBs flavor evaluation, improvement, and quality control.
研究领域:
食品科学
·
感官科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）