Enzymatic hydrolysis behavior on malt bagasse for fermentative sugar disposal in thermostatic and ultrasonic bath

Abstract

This study evaluated the effect of enzymatic hydrolysis on malt bagasse for fermentative sugar extraction in thermostatic and ultrasonic bath. The enzymatic reaction was performed using cellulase, α-amylase, and amyloglucosidase (in separate and combined) on malt bagasse to analyze the hydrolysis effect. For this, a central composite rotational design was applied to evaluate the effect of solid:liquid (malt bagasse w/v) versus enzymatic concentration, considering cellulase, α-amylase, and amyloglucosidase enzymes in mix solution, on fermentable sugars liberation. Then the kinetic fermentative sugars liberation was evaluated in a hydrolysis reaction using cellulase, α-amylase, and amyloglucosidase (in separate and combined) after exposure in thermostatic and ultrasonic bath. From enzymatic mix, the maximum total reducing sugar (TRS) yield was 408.8 and 219.9 mg⋅g −1 in thermostatic and in ultrasound bath, respectively. Kinetic studies showed a TRS variation of 6 to 7 g⋅L −1 for all enzymes. Amyloglucosidase was more promising in assimilation of malt bagasse, responsible for 43% of sugar releasing. Briefly, a low-cost procedure using thermostatic bath improved the hydrolysis reaction. The results from the experiments present a new application where malt bagasse can be employed showing the potential of this brewing industry residue in fomenting processes, as bioethanol production.