# Cold-Adapted Fungi: Goldmine of Biomolecules Applicable in Industry
## 4 Biotechnological Application of Psychrophilic Fungi in Food and Agriculture
### Cold-Active Enzymes
The introduction of psychrophilic enzymes in food processes will undoubtedly accelerate the growth of food enzymes. These enzymes possess unique economic and environmental benefits that will make them an invaluable addition to the food industry and agriculture [53]. The results of recent decades of research have demonstrated that psychrophilic and psychrotolerant fungi are a source of numerous hydrolases, oxidoreductase,transferases, lyases, isomerases, and ligases [5; 14]. In the field of food technology, these enzymes can be employed as precise tools throughout the production process, in addition to serving as biosensors and anti-aging agents. Additionally, enzymes are employed in the remediation of agro-industrial waste, facilitating the generation of high-value products (Table 1). For fungal psychrozymes to be employed in industrial processes, it is essential to achieve sufficient production yields. This necessitates the recombinant expression of enzymes in a mesophilic heterologous host. However, the optimal temperature of the psychrozymes is not compatible with the optimal temperature of the mesophilic host for the enzymes to fold properly. Furthermore, the use of a bacterial expression system, in the form of _E. coli_ for eukaryotic proteins, may also affect their correct folding and prevent post-translational modifications from occurring [96]. One potential solution is to reduce the culture temperature to 18 or 16 \({}^{\circ}\)C at the time of induction. However, this approach has a disadvantage in that it results in a lower growth rate of the host, which in turn causes a reduction in the rate of heterologous production of enzyme/protein. The solution for the overexpression of eukaryotic enzymes is to use also a eukaryotic host. Commonly, this involves employing either _Saccharomyces cerevisiae_ or _Pichia pastoris_. Consequently, the lipase from _Candida albicans_, \(\beta\)-mannosidase from _Aspergillus niger_ CBS 513.88, was overexpressed in the _Pichia pastoris_ strain. In contrast, lipase from _Pseudogymnascus_ sp. P7 was obtained by expression in _Saccharomyces cerevisiae_ BJ5465. In recent years, several strategies have been proposed with the aim of increasing the efficiency of cold protein production in heterologous hosts. These strategies seek to enhance solubility through the use of chaperones, cold-adapted promoters, fusion partners, and the use of psychrophilic hosts, or a combination of these approaches. All of these strategies apply to the expression of psychrophilic bacterial proteins; however, for eukaryotic ones, some of the possibilities are limited [96]. In the case of eukaryotic systems, a strategy involving fusion partners is employed to enhance both the solubility and the expression level of the recombinant enzyme. Concerning psychrophilic hosts, only the _Aspergillus oryzae_ strain was used for the expression of \(\alpha\)-amylase derived from _Pseudogymnascus panmorum_ (formerly _Geomyces panmorum_) [97]. It remains a significant challenge to express psychrophilic enzymes in a mesophilic host, and new solutions must be identified to overcome this hurdle. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Type of Metabolism** & **Enzyme** & **Fungel Species** & **Potential Application** \\ \hline \multirow{5}{*}{analyses} & _Cl  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Type of Metabolism** & **Enzyme** & **Fungal Species** & **Potential Application** \\ \hline \multirow{6}{*}{Carbohydrate metabolism} & \multirow{3}{*}{Xylatase} & ProcelliMiner sp.