How are chitin oligomers produced?
Chitin oligomers can be produced from chitin polymers by partial depolymerisation, either using partial acid or partial enzymatic hydrolysis. Partial acid hydrolysis has the disadvantage that it can easily lead to partial deacetylation, too, yielding chitosan instead of chitin oligomers, if not performed carefully. Enzymatic hydrolysis, typically using chitinase, on the other hand, has the disadvantage that it often leads to almost complete degradation, yielding mostly the dimer chitobiose. In any case, these processes yield mixtures of chitin oligomers, from which single oligomers of a specific degree of polymerization can be produced by chromatographic separation. Pure chitin oligomers are, therefore, rather expensive. An interesting alternative for production of chitin oligomers is their biotechnological synthesis in microbial cell factories, i.e. E. coli cells expressing a bacterial chitin synthase gene leading to cytoplasmic production of chitin tetramers or pentamers in gram quantities.