Development of enzyme cocktails for complete saccharification of chitin using mono-component enzymes from Serratia marcescens

One potential strategy for biorefining of chitin-rich biomass entails enzymatic saccharification, which, so far, has been scarcely explored. Here, saccharification of chitin was explored using response surface methodology available in the MODDE (R) 10 software, to develop optimal cocktails of five mono-component enzymes from Serratia marcescens, three chitinases, SmChiA, SmChiB, SmChiC, a lytic polysaccharide monooxygenase, SmLPM010A (or CBP21), and a beta-N-acetylhexosaminidase, SmCHB (chitobiase). These five enzymes were recombinantly produced in Escherichia coll. For both shrimp and crab chitins, SmChiA was the most abundant (40% and 38%, respectively) in the optimized cocktails, whereas SmChiB, SmChiC and SmLPM010A were present at 30% and 26%, 15% and 23%, and 3% and 2%, respectively. Saccharification yields were 70%-75%, whereas a minimal cocktail of SmChiA and SmCHB gave only 40% saccharification. These results show that enzymatic saccharification of chitin requires multiple enzyme activities applied at dosages similar to those used for saccharification of cellulose. (C) 2017 Elsevier Ltd. All rights reserved.