Regulating the Golgi apparatus sorting of proteinase A to decrease its excretion in Saccharomyces cerevisiae.

Area of Science:

• Biotechnology
• Yeast Genetics
• Food Science

Background:

• Beer foam stability is crucial for beer quality and is negatively affected by proteinase A (PrA).
• Protein sorting at the yeast trans-Golgi network (TGN) involves cofilin and Pmr1, influencing protein secretion.

Purpose of the Study:

• To decrease the excretion of proteinase A (PrA) into beer fermentation broth by manipulating its sorting within yeast cells.
• To enhance beer quality by reducing PrA activity in the final product.

Main Methods:

• Overexpressed the cofilin-coding gene (COF1) and the Pmr1-coding gene (PMR1) in the yeast strain W303-1A.
• Measured the relative gene expression levels and extracellular PrA activity in the engineered strains (W+COF1 and W+PMR1) compared to the parental strain.

Main Results:

• Engineered yeast strains showed significantly increased expression of COF1 (5.26-fold) and PMR1 (19.76-fold).
• Extracellular PrA activity was reduced by 9.24% in W+COF1 and 13.83% in W+PMR1 at the end of fermentation.
• No significant differences in fermentation performance were observed between recombinant and parental yeast strains.

Conclusions:

• Overexpression of COF1 and PMR1 is an effective strategy to reduce proteinase A (PrA) excretion in Saccharomyces cerevisiae.
• This approach offers a promising method for improving beer foam stability and overall beer quality.