Potential of a Penicillium echinulatum enzymatic complex produced in either submerged or solid-state cultures for enzymatic hydrolysis of elephant grass

Renewable energy sources, such as high-biomass yield elephant grass (Pennisetum purpureum) are an alternative feedstock for ethanol production. In addition to its adaptation to different soils and climates, elephant grass can generate approximately 45 t of dry matter per hectare per year. In this study, the enzymatic hydrolysis of elephant grass was evaluated in order to determine the best pretreatment conditions, enzyme load and substrate concentrations. Moreover, a comparison of a hydrolytic enzyme complex of Penicillium echinulatum produced in either solid-state or submerged cultures for enzymatic hydrolysis of elephant grass was performed. The highest yield of reducing sugars was obtained with the hydrolysis of elephant grass pretreated with 3% NaOH (558.56 ± 41.18 mg/g dry mass). Moreover, the enzymes produced in solid-state cultivation were more stable during hydrolysis and released the highest quantities of reducing sugars and glucose.