Chitin-glucan complex production by Komagataella pastoris: Downstream optimization and product characterization

Abstract

Purified chitin-glucan complex (CGC(pure)) was extracted from Komagataella pastoris biomass using a hot alkaline treatment, followed by neutralization and repeated washing with deionized water. The copolymer thus obtained had a beta-glucan:chitin molar ratio of 75:25 and low protein and inorganic salts contents (3.0 and 0.9 wt%, respectively). CGC(pure) had an average molecular weight of 4.9 x 10(5) Da with a polydispersity index of 1.7, and a crystallinity index of 50%. Solid-state NMR provided structural insight at the co-polymer. X-ray diffraction suggests that CGC(pure) has alpha-chitin in its structure. CGC(pure) presented an endothermic decomposition peak at 315 degrees C, assigned to the degradation of the saccharide structures. This study revealed that K. pastoris CGC has properties similar to other chitinous biopolymers and may represent an attractive alternative to crustacean chitin derived-products, being a reliable raw material for the development of new/improved pharmaceutical, cosmetic or food products. (C) 2015 Elsevier Ltd. All rights reserved.