Yeast Strain Incorporating Artificial Isoenzymes and Method for Producing Glutathione Using the Same

High-Yield Production of Active Glutathione Using Recombinant Yeast with an Artificial Isoenzyme System

This technology involves a yeast strain engineered for glutathione production by introducing a recombinant expression vector containing a truncated HXT7 promoter and GSH1, GSH2, and gshF genes, along with the co-transformation of chaperone genes groL and groS. It also includes a production method for recovering active glutathione through the cultivation of this strain.

While glutathione can be produced via chemical or enzymatic reactions, high production costs arise from the need to purify the bioactive L-isomer from racemic mixtures and the requirement for ATP supply. Consequently, yeast fermentation has become the mainstream for commercial production; however, wild-type strains have limited intracellular content, and simple overexpression of biosynthetic enzymes has struggled to simultaneously improve both the active ratio and overall yield.

This technology utilizes an artificial isoenzyme configuration that simultaneously expresses glutathione biosynthetic enzymes from different origins under the same strong promoter, combined with chaperone co-expression to ensure proper enzyme folding and maintain a high ratio of active glutathione. It is compatible with batch, fed-batch, and continuous cultivation, with recovery possible from cells, culture broth, or lysates. Applicable to the fermentation-based production of glutathione for food, pharmaceutical, and skin-whitening applications, it improves cost structures through enhanced yields.

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Key Features:

• A yeast strain for glutathione production transformed with a recombinant expression vector containing a truncated HXT7 promoter and GSH1, GSH2, and gshF gene constructs
• A Saccharomyces cerevisiae strain further transformed with a recombinant expression vector containing groL and groS gene constructs
• A Saccharomyces cerevisiae strain deposited under accession number KCCM13231P, used for glutathione production
• A production method comprising the steps of culturing the yeast strain in a batch, fed-batch, or continuous manner and recovering glutathione from the cells or culture broth

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This invention was developed with support from the Rural Development Administration’s project for the development and commercialization of futuristic yeast strains with high production of microbial polysaccharides and proteins.

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