Fed-batch enzymatic hydrolysis of plantain pseudostem to fermentable sugars production and the impact of particle size at high solids loadings

In this work, the performance of a fed-batch high solids enzymatic hydrolysis of plantain pseudostem was studied at different particle sizes. The plantain pseudostem was pretreated with an alkaline hydrogen peroxide medium. Two set of experiments were carried out in a stirred tank bioreactor at substrate concentrations of 10% and 15% w/v, combined each one with particle sizes #20–40, #40–60, and # > 100, in 1 L of reaction volume. Particle sizes of #20–40 and #40–60 allowed around 99% of holocellulose conversion with a substrate concentration of 10% w/v, and 91% with 15% w/v; meanwhile enzymatic hydrolysis at particle size of mesh # > 100 yielded 70% and 73%, with a substrate concentration of 10% and 15% w/v, respectively. The conditions recommended for enzymatic hydrolysis at high solids of 15% w/v through fed-batch operation are particle size #20–40 and 6 h of reaction, achieving 91% of holocellulose conversion and 82 g/L of reducing sugars.