Enzymatic conversion of Chitin into high value compounds
Chitin is a long-chain polymer of N-acetylglucosamine, which is a derivative of glucose. Chitin is the main component of the exoskeleton of crustaceans, such as crabs, shrimp, and insects. It is furthermore found in cell walls of fungi, the radulae of mollusks and the internal shells and beaks of cephalopods, such as octopuses.
Non-processed chitin has no economic value and is available in large amounts as by-product of the food industry. Chitosan, a linear polymer composed of multiple D-glucosamine and N-acetyl-D-glucosamine monomers, can be produced from chitin by either enzymatic or chemical treatment to oligomers with defined chain length and degree of acetylation. Chitosan has a number of commercial and biomedical uses: It has proven antibacterial, antifungal and antiallergenic properties and is therefore of interest for the agricultural- and pharmaceutical industry. It can be used as seed treatment and bio pesticide, to prevent fungal infections of seeds and plants. In the pharmaceutical industry, it can be used in bandages or other hemostatic products as an antibacterial agent.
The research group has isolated a novel, non-described, bacterial strain („Chi5“) from environmental samples, which is able to convert chitin into chitosan oligosaccharides of defined chain lengths by a mixture of specialized enzymes. We are aiming to reveal the full potential of the enzyme cocktail produced by the marine microbe by sequencing its whole genome, followed by identification and subsequent recombinant production of the enzymes in a high performance expression system. After characterization of the single enzymes, the team will design a specialized cocktail composed of endo- and exochitinases able to generate chitin/chitosan oligomers of defined chain length from crab-chitin as basic raw material. By addition of a deacetylase, the required degree of acetylation of the sugar oligomers will be ensured.
The advantage of this approach is that long chained chitin/chitosan oligomers can be produced from prawn shells – a cheap by-product of the food industry – without the necessity of complex chemical processes using specialized enzyme mixtures. This “green approach” goes without the use of polluting chemicals; furthermore it’s much faster, more economical and more precise due to the high specificity of the enzymes. The enzymatic approach offers many advantages such as higher specificity, speed and product quality compared to a chemical process. AMIBM holds all rights related to the isolated microorganism, therefore no third parties are involved in terms of commercialization of the resulting products or further improvement of the enzymes/strain by molecular evolution.