Construction of an Immobilized Enzyme Membrane Reactor for Efficient and Sustainable Conversion of Ionic Liquid/Ultrasound-Pretreated Chitin
Jing Li, Xiangzhao Mao
Abstract
In this study, an immobilized enzyme membrane reactor (EMR) was constructed and applied into the hydrolysis of chitin for the first time. Chitinase from Streptomyces albolongus ATCC 27414 (SaChiA4) was immobilized on the support layer of the regenerated cellulose ultrafiltration membrane (1 kDa) via adsorption with an immobilization efficiency of approximately 100%. Through pre-treatment with ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) and ultrasound, the conversion rate of chitin achieved 100% in a biocatalytic membrane (loaded with 13.24 U/cm2 SaChiA4) flow-through cycle operated at 40 °C, 200 rpm, and 2.5 bar for about 14 h. The SaChiA4 EMR maintained a high chitin conversion rate of 75.60% after five continuous reaction cycles at 40 °C. After storage at 4 °C for 30 days, the conversion rate remained 68.95% in the fourth reaction cycle. This biocatalytic UF membrane reactor could show potential in efficient and sustainable conversion of chitin.