# Metabolic Potential of Halophilic Filamentous Fungi--Current Perspective
## 5 Biomolecules Produced by Halophilic Fungi
### Biosurfactants and Surface-Active Proteins  
Biosurfactants are a diverse group of surface-active amphiphilic molecules produced by many microorganisms that have developed mechanisms enabling them to access hydro \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Halophilic Fungi** & **Enzyme** & **Salinity Growth** & **References** \\ \hline _Marasmiellus_ sp. CBMAI 1062 & & & \\ \hline _Peniophora_ sp. CBMAI 1063 & & & \\ \hline _Flavodon flavus_ & Lignin peroxidase, manganese & Diluted seawater (1:1) & [82] \\ \hline _Tinctoprellus_ sp. CBMAI 1061 & Lignin peroxidase & Artificial seawater & [50] \\ \hline _Mucor racemosus_ CBMAI 847 & Lignin peroxidase, manganese & & \\ \hline _Apergillus sclerotium_ CBMAI 849 & Lignin peroxidase, & & \\ \hline _Cladosporium cladosporoides_ & manganese peroxididases & & \\ \hline CBMAI 857 & & & \\ \hline _Apergillus yadovii_ EXF-12860 & & & 1.0 M NaCl & [71] \\ \hline _A Aspergillus destruens_ EXF-10411 & & & 1.9 M NaCl & \\ \hline _Hortaaa werneckii_ EXF 225; & & & \\ MZKI B-736 & Glycerol-3-phosphate & & 1.0 and 3.0 M NaCl & [83] \\ \hline _Wallemia ichthyophaga_ EXF 994 & & & 1.8 and 4.5 M NaCl & \\ \hline _Apergillus yadovii_ EXF-12860 & & Catalase, glutathione peroxidase & & \\ \hline _Apergillus yadovii_ EXF-12860 & & and superoxide & 1.0 M and 5.13 M NaCl & [84] \\ \hline _Cadophora_ sp. TS2 & & & \\ \hline _Emericellopsis_ sp. TS11 & & & \\ \hline _Pseudogymoascus_ sp. TS12 & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Oxidoreductases obtained from halophilic fungi. carbons more easily. Microorganisms producing biosurfactants can be found everywhere, also among extremophiles that thrive in a wide range of temperatures, various pH, and salinity, which gives them industrial advantages over chemical surfactants in terms of lower toxicity and higher biodegradability [87]. Biosurfactants produced by halophilic microorganisms are capable of operating under growth limiting conditions. These compounds are characterized by the ability to work in the environment of physiological saline, hypersaline environments, and under increased temperature and pH. These characteristics make them valuable in industrial processes [88; 89]. In the face of the antimicrobial resistance crisis, the antimicrobial and antiviral activity indicates the enormous potential of halophilic biosurfactants as antimicrobial agents in the field of biomedicine. These compounds can also be used in gene therapy and vaccine production [90; 91]. Halophilic biosurfactants also show antioxidant activity and a strong anti-adhesive effect. The high stability of emulsions formed by halophilic biosurfactants also allows their use in the processes of mobilizing heavy crude oil, cleaning oil sludge from crude oil storage facilities. In addition, these compounds can be used to remove pollutants in highly saline wastewater or to increase the effectiveness of reclamation of saline environments polluted with hydrocarbons, including coastal bioremediation [92]. The group of molecules counted as microbial biosurfactants includes glycolipids, phospholipids, neutral lipids, lipoproteins, fatty acids, polymeric, and particulate biosurfactants [54]. Some halophilic filamentous fungi have the ability to produce biosurfactants. Marine fungi _Aspergillus usatus_ (MSF3) isolated from the marine sponge _Fasciospongia cavernas_ produced high yield of biosurfactant characterized as a glycolipoprotein [54]. _Aurebosidium pullulans_ produced several different biosurfactants with 5-hydroxy-2-decenoic acid delta lactone (known as massoia lactone) as the main active compound [93]. Among surface-active proteins, hydrophobins have been described as the most powerful with the greatest ability to reduce the surface tension of water [94]. They are small (<20 kDa) cell-wall proteins produced by filamentous fungi, playing diverse roles in their growth and development [95]. Hydrophobins could only be found in fungi, not even yeasts contain genes encoding these proteins [27].