Enhanced Fermentable Sugar Production from Enteromorpha Polysaccharides by the Crude Enzymes of Vibrio sp. H11

Abstract

In recent years, large-scale outbreaks of the green alga <i>Enteromorpha prolifera</i> in China’s offshore waters have posed a serious threat. This study aimed to improve <i>Enteromorpha</i> polysaccharide (EP) enzymatic sugar production using the hydrolase system of <i>Vibrio</i> sp. H11, an EP-utilizing microbial strain. Strain H11 was found to contain 711 carbohydrate-related genes, and 259 genes belong to glycoside hydrolases that have the potential to hydrolyze EP. To maximize the capability of strain H11 to hydrolyze EP, both the culture medium and the composition were optimized. Response surface methodology analysis showed that maximal enzymatic production from strain H11 was 8.43 U/mL after 26-h incubation. When 50 g/L of EP were treated with crude H11 enzyme, the concentration of fermentation sugars increased by 36.12%. Under these conditions, the hydrolysates were capable of generating 3,217 mL/L of biogas and 6.74 g/L of biosolvents, with increases of 28.17 and 7.29%, respectively, compared to controls. The combined application of the H11 enzymatic system and anaerobic fermentation has the potential to improve the comprehensive application of EP.