Paper accepted: Dissecting and optimizing bioactivities of chitosans by enzymatic modification

Today, Dr. Carolin Richter’s manuscript on the biotechnological optimisation of bioactive chitosans for sustainable agriculture was finally accepted in the highly reputed journal Carbohydrate Polymers. This is the result of more than a decade of research into the enzymatic modification of chitosans to fine-tune their molecular structure and their biological activities. In a close collaboration, Dr. Stefan Cord-Landwehr provided and characterised the recombinant enzymes which Caro used to modify well-characterised “second generation” 2G-chitosans provided by our long-term chitosan producer, Dr. Dominique Gillet from Stellar Biosol. Stefan then analysed the structures of the enzymatically modified “third generation” 3G-chitosans, and Caro tested their biological activities. She found that depending on the characteristics of the enzyme used, the products differed strongly in their e.g. antimicrobial and plant strengthening activities. Interestingly, transcriptomic analyses initially supported by Dr. Ratna Singh and Judith Ryll showed that the 2G-chitosan polymer used as a substrate was best in stimulating photosynthesis, while the products of a specific chitosanase treatment were best in stimulating disease resistance. This work creates a wide-open window of opportunities to biotechnologically fine-tune biological activities of chitosans by using enzymes to convert 2G- into 3G-chitosans. Importantly, the whole, patent-protected process is easily scalable and, thus, suitable for commercial applications.