Commercial cellulases from Trichoderma longibrachiatum enable a large-scale production of chito-oligosaccharides

Chito-oligosaccharides (COSs) are a substance class of high interest due to various beneficial bioactive properties. However, detailed mechanistic and application-related investigations are limited due to the poor availability of COSs with defined structural properties. Here, we present the large-scale production of COSs with defined degree of N-acetylation using a commercial cellulase preparation from Trichoderma longibrachiatum. The enzyme preparation was found to exclusively produce COSs lacking of acetyl groups while MS/MS analysis indicated a cellobiohydrolase to be the responsible for hydrolysis with the enzyme preparation. MS and NMR analysis proved the low content of acetyl groups in the COS mix and oligomers with a degree of polymerization (DP) of 2-6 were obtained. The low cost enzyme source was further exploited for large-scale production in a 20 g batch and resulted a COSs yield of 40 %. An inexpensive enzyme source for the production of bioactive COSs was successfully implemented and thorough product analysis resulted in well-defined COSs. This strategy could improve the access to this substance class for a more detailed investigation of its various biological activities.