<p>Cold atmospheric plasma is emerging as a non-thermal and non-invasive tool for influencing microbial metabolism by modifying bioreactor conditions. This paper validates the effect of a cold atmospheric helium plasma jet on recombinant thaumatin bioproduction by genetically modified <i>Komagataella phaffii</i>. The yeast produced recombinant thaumatin with methanol serving as the carbon and energy source. The cell-free production medium was treated with a helium plasma jet once for 2, 4, 6, and 8&#xa0;min before inoculation, while the control bioprocess remained untreated. The same treatments were repeated daily on the cell cultures. The results showed no significant effect of the treatment time (2–8&#xa0;min) on thaumatin production. However, the application of plasma treatments, regardless of the duration, resulted in significant enhancement of 13.3% in protein production compared to the control. No significant difference was observed between residual methanol concentrations with and without plasma treatments, leading to the conclusion that the yield of thaumatin produced per quantity of methanol consumed increased due to plasma treatments. This study thus confirms the hypothesis that cold atmospheric plasma enhances protein production and highlights the probable role of plasma-generated reactive species in this enhancement.</p>