VALUABLE Enzymatically produced chitin and biomass hydrolysate

This document is still a draft pending of the EC's approval. Enzymatic hydrolysis of Aspergillus niger biomass offers a sustainable and eco-friendly route towards the production of chitin and chitin-derived materials, while at the same time yielding a hydrolysate that can be used to produce yeast oils. We have demonstrated that by using specific enzymes to break down the fungal cell wall, chitin can be efficiently extracted without the use of harsh chemicals. This process not only preserves the integrity of the chitin but also yields a nutrient-rich hydrolysate, making it ideal for various applications in agriculture, biotechnology, and medicine.Through careful optimization of enzymatic procedures, in the VALUABLE project, biomass solubilization efficiencies of 73-78% have been achieved which is approaching the expected theoretical maximum of 80-85% as outlined in Deliverable 2.1. The soluble fraction is rich in glucose, cellobiose, mannose, and amino acids/peptides. The solid fraction contains chitin at high relative purity. Using ¹H NMR spectroscopy, the degree of acetylation (DA) of the chitin was determined. The enzymatically extracted chitin from fungal biomass exhibited a DA of 99%, which is higher than the 96% observed in commercial chitin. The lower DA in commercial chitin is a result from the harsher (and less environmentally friendly) extraction and purification processes, which involve strong alkaline and acidic conditions, leading to partial deacetylation.Additionally, using internal standards and solid-state NMR, the purity of the chitin produced enzymatically from fungal biomass was confirmed to be ≥90%.Overall, the completion of Deliverables 2.1, 2.3, 2.4, and 2.5 demonstrates the successful hydrolysis of fungal biomass and the enzymatic extraction of high-quality chitin, laying the groundwork for further upscaling of chitin production (from up to 1 kg, to > 10 kilo) and further developments in the green production of yeast oils and chitin-derived materials.