Fungal chitinases: diversity, mechanistic properties and biotechnological potential

Abstract

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.

Investigating chitin deacetylation and chitosan hydrolysis during vegetative growth in Magnaporthe oryzae

“…The mycelium of the Δ cda1 mutant was less susceptible to degradation by cell wall lysing enzymes, suggesting that the properties of the cell wall were in some way altered by the loss of chitin deacetylation. However, this result is somewhat counterintuitive; one would expect the loss of chitosan to render the cell wall more susceptible to degradation by chitinases, because chitosan is a poor substrate for these enzymes (Hartl, Zach, & Seidl‐Seiboth, 2012). The increased resistance of the cell wall to enzymatic degradation in Δ cda1 could perhaps be attributed to a reduction in cell wall permeability.…”

“…Both chitosanases and chitinases are able to hydrolyze a mixed GlcN–GlcNAc linkage (Hartl et al . , 2012), and so chitinases are able to hydrolyze chitosan to some degree, depending on the degree of deacetylation. Thus, from the perspective of cell wall remodelling by cell wall hydrolases, it is difficult to make a clear distinction between chitin and chitosan.…”

Isolation and Identification of Chitinase Producing Native Fungi From Saltpan of Puthalam, Kanyakumari District, Tamil Nadu, India

“…Chitinases are widely distributed in microorganisms, the filamentous fungi including Trichoderma, Oenicillium, Penicillium, Lecanicillium, Neurospora, Mucor, Beauveria, Lycoperdon, Aspergillus, Myrothecium, Conidiobolus, Metharhizium, Stachybotrys and Agaricus [22][23][24].…”

Raman Spectroscopy and Density Functional Theory Calculations of β-Glucans and Chitins in Fungal Cell Walls

“…9,10 It is thus possible to differentiate the certain fungal species by carefully examining the Raman spectra of chitins and glucans.…”