Utilization of Peach-palm waste for cost-effective amylase production by Trichoderma stromaticum : Stability and industrial potential

Abstract

Amylases are among the most important enzymes for biotechnological and industrial applications. The present work aimed to analyse the use of agro-industrial waste as a low-cost substrate to the obtention of the amylase by the fungus Trichoderma stromaticum AM7 (CCMB617P) under solid state fermentation (SSF). The fungus was able to produce amylase using solely peach palm waste as a substrate (29.2 U/gds), however when a simplex centroid mixture design was applied to optimise the composition of the nitrogen source, peptone, and ammonium phosphate (7:3 w/w) in a total of 1% were added and an increase of the 45% (42.4 U/gds) was observed in relation to the activity initially obtained. The physicochemical characterisation of amylase revealed the optimum activity at pH 4.0 and temperature 50 °C to 60 °C. The amylase retained around 90% of its activity in a pH range from 4.0 to 7.0 and a temperature 40 °C to 70 °C, and 60% in a range from 80 °C to 100 °C, for up to 1 h. Amylase showed an increase in its activity with Al2+, Ag2+, and Co2+, however, the Cu2+negatively influenced the enzymatic activity. The enzyme was stable in the presence of SDS and β-mercaptoethanol. The cost-effective enzyme extraction and stable amylase highlight its strong potential in industry applications, especially in food processes.