Plasma-activated water improves the accessibility of chitinase to chitin by decreasing molecular weight and breaking crystal structure

Yuanchang He; Chenghui Zhang; Xueying Zhang; Yongcheng Li; Qiao Zhang

doi:10.1016/j.carres.2024.109144

Plasma-activated water improves the accessibility of chitinase to chitin by decreasing molecular weight and breaking crystal structure

Carbohydr Res. 2024 May 7:540:109144. doi: 10.1016/j.carres.2024.109144. Online ahead of print.

Authors

Yuanchang He¹, Chenghui Zhang¹, Xueying Zhang¹, Yongcheng Li², Qiao Zhang³

Affiliations

¹ College of Food Science and Engineering, Hainan University, Haikou, 570228, China.
² College of Food Science and Engineering, Hainan University, Haikou, 570228, China. Electronic address: 990491@hainanu.edu.cn.
³ Guangxi Key Laboratory of Health Care Food Science and Technology, Hezhou University, Hezhou, 542899, China. Electronic address: zq2203@hzxy.edu.cn.

PMID: 38733729
DOI: 10.1016/j.carres.2024.109144

Abstract

Chitooligosaccharides, the hydrolysis products of chitin, have superior biological activities and application value to those of chitin itself; however, the ordered and highly crystalline structure of chitin renders its degradation by chitinase difficult. Herein, the effects of plasma-activated water (PAW) pre-treatment on the physicochemical properties, crystal structure, and enzymatic hydrolysis of chitin were investigated. The hydrolysis of PAW-pre-treated chitin (PAW activation time of 5 min) using chitinase from Vibrio harveyi (VhChit2) yielded 71 % more reducing sugar, compared with that from untreated chitin, with the degree of chitin hydrolysis increasing from 13 % without pre-treatment to 23 % post-treatment. Moreover, the amount of VhChit2 adsorbed by chitin increased from 41.7 to 58.2 mg/g. Fourier transform infrared spectrometry revealed that PAW could break the β-1,4-glycosidic bonds of chitin (but had no effects on the hydrogen and amido bonds), thereby decreasing the molecular weight and crystallinity of the polysaccharide, which caused its structural damage and enhanced its enzymatic hydrolysis by chitinase. Consequently, PAW pre-treatment can be considered a simple, effective, and environmentally-friendly method for the biotransformation of chitin as its easier hydrolysis yields high-value products.

Keywords: Biodegradation; Chitin; Chitinase; Oligosaccharide; Plasma-activated water.