## 4 The Behavior of _Saccharomyces cerevisiae_ in Stressors Action
\begin{table}
\begin{tabular}{c c} \hline \hline
**Gene Type** & **Function** \\ \hline _Acc2_ & Transcription factor that early activates G1-specific gene expression; may be involved in acetic acid tolerance \\ \hline _Crz1_ & Transcription factor that activates the copying of genes involved in the stress response \\ \hline _Nrg1_ & Intervenes in glucose repression and negatively regulates many processes, including filamentous growth. Involved in \\  & tolerance to salt, oxidative stress, and acetic acid \\ \hline _Rim101_ & Repressive transcription factor involved in cell wall structuring and pH response. It also plays a role in acetic acid tolerance \\ \hline _Sth5_ & Transcription factor involved in multidrug resistance, oxidative stress response, and acetic acid tolerance \\ \hline _Usv1_ & Transcriptional regulator of genes involved in growth of non-fermentable carbon sources and response to osmotic stress \\ \hline _Cmr3_ & YPR015C-related transcription factor affects the copying of genes involved in cell defense and rescue, but also in DNA \\  & processing and the cell cycle \\ \hline _Msn2/4_ & Activators of transcription, regulate the general stress response. Overwriting Msn2 improves ethanol tolerance \\ \hline _Prd1/Prd3_ & Involved in tolerance to hydroxymethylfurral (HMF) and ethanol, and in response to salt stress \\ \hline _Ume6_ & Key transcriptional regulator of early meiotic genes, involved in acetic acid tolerance and salt stress response \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Zinc finger proteins with role in stress tolerance of _S. cerevisiae_ yeast [74]. until the end of fermentation [2]. Table 5 mentions some actions that can be carried out to reduce the stress that occurs during fermentation. The genetic modifications made to improve the chains of _S. cerevisiae_ also play an important role. Mutagenesis, hybridization, and protoplast fusion are some of the classic techniques used to increase stress resistance. As for newer methods, gene editing technologies show promising results in this area. With the help of one of these, the desired genes can be deleted and inserted as precisely as possible by clustered and regularly interspersed palindromic repeats (CRISPR) and by CRISPR nuclease associated with protein 9 (Cas9). Following application, tolerance to ethanol, acetic acid, and temperature were increased considerably. In the culture medium, stress can occur by itself under the action of certain factors, but it can also be induced to manipulate the cells to produce as much of the final product as possible. Table 6 shows some examples of how types of stress are used to influence yeasts [2]. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Stress Type** & **Cell Response** & **Industrial Application** \\ \hline Osmotic shock & Glycerol and trehalose levels increase by lowering the osmotic potential of the growth medium & Usage of tolerant yeasts in fermentation processes \\ \hline UV irradiation & Irradiated yeasts convert membrane ergosterol to vitamin D2 & Vitamin-D2-enriched yeasts for baking and nutraceuticalals \\ \hline Oxidative stress & Induction of catalase and superoxide dismutase, stimulation of membrane sterol, and unsaturated fatty acid synthesis in aerobic environment & Oxygenated yeasts will have a higher stress tolerance during the fermentation process due to the high amounts of ergosterol and oleic acid in the membrane \\ \hline Heat shock & Yeast cells with high levels of trehalose have a higher tolerance against stress after heat shock & Usage of frozen dough for baking \\ \hline Heat and salts & Self-digestion & Obtaining yeast extracts and yeast beta-glucan \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Influence of stress on yeasts in industrial applications [2].