Phytase production by white-rot fungi cultivated in liquid medium with particulate agro-industrial byproducts

Abstract

This study aimed to screen phytase-producing basidiomycetes by submerged cultivation (SmC) with particulate agro-industrial byproducts and evaluate the enzyme's thermal and pH stability. Five among eight fungal species produced high phytase activity (> 300 U mL-1) after seven days in SmC. Ganoderma sp., the best phytase producer (1130 U mL-1), was grown in a liquid medium with particulate agro-industrial byproducts (coffee husks, citric pulp, sugarcane bagasse, and soybean hulls). Soybean hulls increased phytase activity (16%) and productivity (2.3-fold). The residual phytase activity was determined after 120 min incubation in different pH (pH 3, 5, 7, and 9) and temperatures (30, 50, and 70 oC). Phytase activity remained stable at pH ranging from 3 to 9, with 100% activity retention after 120 min at pH 7. Furthermore, Phytase retained more than 60% activity when incubated for 120 min from 30 oC to 70 oC. Our findings support future studies using Ganoderma sp. and particulate soybean hulls for phytase production for potential use in the animal feed industry.