Chitin derivatives, chitosan and substituted chito-oligosaccharides have a wide spectrum of applications ranging from medicine to cosmetics and dietary supplements. With advancing knowledge about the substrate-binding properties of chitinases, enzyme-based production of these biotechnologically relevant sugars from biological resources is becoming increasingly interesting. Fungi have high numbers of glycoside hydrolase family 18 chitinases with different substrate-binding site architectures. As presented in this review, the large diversity of fungal chitinases is an interesting starting point for protein engineering. In this review, recent data about the architecture of the substrate-binding clefts of fungal chitinases, in connection with their hydrolytic and transglycolytic abilities, and the development of chitinase inhibitors are summarized. Furthermore, the biological functions of chitinases, chitin and chitosan utilization by fungi, and the effects of these aspects on biotechnological applications, including protein overexpression and autolysis during industrial processes, are discussed in this review.

Background: EPL1 belongs to the cerato-platanin protein family found exclusively in fungi and associated with fungus-host interactions. Results: EPL1 self-assembles at air/water interfaces, increases the polarity of surfaces and solutions, and binds to chitin. Conclusion:The reported properties for EPL1 show that cerato-platanin proteins are clearly different from hydrophobins. Significance: This study reports several novel properties for cerato-platanin proteins.

Enzymes from extremophiles have always been of great interest for biotechnology because of their ruggedness against various stress factors. We have isolated, cloned, heterologously expressed and characterized a thermostable old yellow enzyme (OYE) from Geobacillus kaustophilus. In addition to the expected enone reduction, GkOYE also catalyzes the reverse reaction, i.e., the desaturation of C À C bonds adjacent to a carbonyl to give the corresponding a,b-unsaturated ketone. The reaction proceeds at the expense of molecular oxygen without the need for a nicotinamide cofactor and represents an environmentally benign alternative to known chemical dehydrogenation methods.