The present invention provides an acid-tolerant Saccharomyces cerevisiae strain and use thereof. By using exogenously added malic acid as a stress, an acid-tolerant mutant S. cerevisiae strain MTPfo-4 is obtained by directed evolution screening in the laboratory, which tolerates a minimum pH of 2.44. The mutant strain MTPfo-4, tolerant to multiple organic acids, has an increased tolerance to exogenous malic acid of up to 86.6 g/L. The mutant strain MTPfo-4 obtained is further identified. The mutant strain grows stably and well, and can tolerate a variety of organic acids (lactic acid, malic acid, succinic acid, fumaric acid, citric acid, gluconic acid, and tartaric acid). It also has a strong tolerance to inorganic acids (HCl and H.sub.3PO.sub.4). This is difficult to achieve in the existing research and reports of S. cerevisiae. The strain is intended to be used as an acid-tolerant chassis cell factory for producing various short-chain organic acids.

A yeast strain producing glutathione (GSH) and aldehyde dehydrogenase, and more specifically, the yeast strains Saccharomyces cerevisiae Kwon P-1 KCTC13925BP, Saccharomyces cerevisiae Kwon P-2 KCTC14122BP, and Saccharomyces cerevisiae Kwon P-3 KCTC14123BP, which produce both glutathione and aldehyde dehydrogenase.

The present invention describes a recombinant yeast cell functionally expressing one or more heterologous nucleic acid sequences encoding for ribulose-1,5-phosphate carboxylase/oxygenase (EC4.1.1.39; Rubisco), and optionally one or more molecular chaperones for Rubisco, and one or more phosphoribulokinase (EC2.7.1.19; PRK), wherein one or more genes of the non-oxidative branch of the pentose phosphate pathway are overexpressed and/or wherein said yeast cell comprises a deletion or disruption of a glycerol-3-phosphate dehydrogenase (GPD) gene.

The present invention relates to a synthetic promoter capable of controlling the expression of a target gene at various locations in the genome of an acid-resistant strain, and more particularly to a synthetic promoter including a core promoter derived from an acid-resistant strain and an upstream activating sequence (UAS) element serving as an enhancer. When the present invention is applied to a variety of genetic and metabolic engineering techniques for acid-resistant yeast, various metabolic networks can be configured as desired while controlling the expression level of the target gene, so a method of producing various metabolites using acid-resistant yeast is provided, and the cost of producing the metabolites can be greatly reduced depending on the properties of the acid-resistant yeast.

The present disclosure belongs to the field of bioengineering, and relates to breeding of industrial microorganisms, in particular to a genetically engineered strain of Saccharomyces cerevisiae, method for constructing the same, and its use for brewing, the genetically engineered strain of Saccharomyces cerevisiae heterogeneously overexpresses an acetaldehyde dehydrogenase gene ALD6, an acetyl-CoA synthase gene ACS1 and an alcohol acyltransferase gene AeAT9. The Saccharomyces cerevisiae strain with high yield of ethyl acetate and low yield of higher alcohols provided by the present disclosure not only maintains excellent ethanol fermentation characteristics, but also reducing the production of higher alcohols which adversely affect the comfort after drinking, which is of great significance for a well-maintained and strengthened flavor characteristics of Chinese Baijiu, an improved and stabilized quality thereof, and even a reform in the fermentation process thereof.

Methods of standardizing a fermentation process may include obtaining a fluidic sample, measuring one or more physical parameters of the sample, comparing the measurement of the physical parameter of the material to a baseline value of the physical parameter for the fermentation process, and responsive to a deviation of the measurement of the physical parameter from the baseline value, determining a remediation action based on a correlation between the physical parameter and regulatory genes of a fermentation organism.

Methods and systems for the enhancement of bioproduct process yields. The present invention provides systems and methods for improvement of the carbon conversion efficiency by yeast of an organic substrate such as a fermentable sugar to a fermentation product such as ethanol. Exemplary yield-increasing/growth-inhibitory compounds include tyrosol (TyrOH), 2-phenylethanol (PheOH), and tryptophol (TrpOH). Immobilization of the yeast, such as in a porous bead or pellet, can further increase yield. Exemplary immobilization included immobilization in calcium alginate beads. The system and methods taught herein demonstrate that product yield such as ethanol yield can be improved by adding yeast yield-increasing/growth-inhibitory molecules to reduce cell growth of yeast species, such as S. cerevisiae, suggesting a strategy to improve the yield of ethanol and other yeast fermentation products by manipulating native biological control systems.

The invention is directed to an engineered yeast including an exogenous nucleic acid encoding a glucoamylase comprising SEQ ID NO:1 and SEQ ID NO:4, or a variant thereof. The engineered yeast are able to provide glucoamylase into a fermentation media and cause degradation of starch material generating glucose for fermentation to a desired bioproduct, such as ethanol. High titers of bioproduct (e.g., 70 g/kg of ethanol) can be achieved, along with low residual glucose levels. Further the yeast exhibit good growth and bioproduct product at temperatures of 32? C. or greater.

Microbial starter cultures. More specifically, a method for preparing a microbial culture such as a lactic acid bacteria (LAB) starter culture wherein at least one microbial strain such as a lactic acid bacteria and at least one inactivated yeast strain is inoculated in a culture medium.

Provided herein are compounds, compositions, and methods for recovery of one or more water-immiscible compounds from microbial biomass.