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 disclosure provides an engineered microorganism capable of producing malonic acid, malonate, esters of malonic acid, or mixtures thereof. The engineered microorganism includes a malonate-semialdehyde dehydrogenase that is heterologous to a native form of the engineered microorganism and comprises at least 90% sequence identity to any one of SEQ ID Nos: 7, 9, 11, 13, 15, 17, 19, 21, 23, 27, 29, and 31, wherein the engineered microorganism is capable of producing about 9 g/L to about 250 g/L of malonic acid, malonate, esters of malonic acid, or mixtures thereof.

Disclosed is a method of producing lactic acid using a recombinant acid-resistant yeast with inhibited lactate metabolism and alcohol production. More specifically, disclosed are a recombinant acid-resistant yeast in which lactate consumption reaction is reduced and which is imparted with lactic-acid-producing ability to thereby exhibit improved lactic-acid-producing ability and reduced ethanol production, and a method of producing lactic acid using the same.

Methods of and system for growing and maintaining an optimized/ideal active yeast solution in the yeast tank and fermenter tank during the fermentation filling cycle are provided. A new yeast stage tank is used between the yeast tank and the fermenter tank allowing yeast to rapidly produce a huge amount of active young yeast cells for a fermenter during the filling period. A measurable and useful controlling factor, % DT/% Yeast by weight ratio (or “food” to yeast ratio), is used (e.g., % DT=glucose), which offers information on the health status of the yeast. The controlling factor is used to control the status of the yeast throughout the entire process.

The present invention relates to a yeast strain used in the production of a fermented beverage, wherein the yeast strain is a hybrid obtained by a mass-mating hybridisation process between haploid spores selected from Saccharomyces cerevisiae strain Y927, strain Y115, strain WI011, strain WI017 and strain WI018, or wherein the yeast strain is an inbred strain of said hybrid. The present invention further relates to a yeast slurry, a method for brewing a fermented beverage, and a malt or tea-based beverage obtained on the basis of a fermentation process.

The present invention relates to the fields of industrial biotechnology, renewable raw materials and production of organic acids. Specifically, the invention relates to a method of producing an organic acid or a salt thereof. Still, the present invention relates to a mixture comprising legume molasses and calcium hydroxide or a mixture obtained by combining a carbon substrate composition comprising legume molasses and an aqueous suspension comprising calcium hydroxide, for producing an organic acid or a salt thereof by a microorganism, and use of said mixture for producing an organic acid or a salt thereof. Still further, the present invention relates to a method of producing one or more products selected from the group consisting of polymers, polyesters and polylactic acids.

The present disclosure provides genetically engineered microorganisms for the simultaneous fermentation of pentose and hexose sugars, for example, glucose and xylose. The microorganisms can be modified to express AtSWEET polypeptides, LST1 polypeptides, mutants thereof, homologs thereof or combinations thereof. Also provided are methods of co-fermenting hexose and pentose sugars, methods of increasing the conversion of lignocellulosic biomass via microbial fermentation, and methods of generating biofuel.

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 invention relates to the field of molecular biology and cell biology. More specifically, the invention relates to CRISPR guide-RNA expression strategies for multiplex genome engineering.