Production of β‐galactosidase by Trichoderma sp. through solid‐state fermentation targeting the recovery of galactooligosaccharides from whey cheese

Aims Optimization of β‐galactosidase production by Trichoderma sp. under solid‐state fermentation using wheat bran as solid substrate through an experimental design and its application targeting the recovery of galactooligosaccharides (GOS) from whey cheese. Methods and Results The β‐galactosidase production by Trichoderma sp. increased 2·3‐fold (2·67 U g−1 of substrate) culturing the fungus at 30°C for 187 h, at an inoculum of 105 spores per ml, and a 1 : 1·65 (w/v) ratio of wheat bran to tap water. The best enzyme activity was obtained at 55°C and pH 4·5. The catalytic activity was maintained for up to 180 min incubating at 35–45°C, and above 50% at acidic or alkaline pH for up to 24 h. It also presented resistance to chemical compounds. β‐galactosidase catalysed the hydrolysis of the lactose and the transgalactosylation reaction leading to the production of GOS. Conclusion Trichoderma sp. produced β‐galactosidase with transgalactosylation activity that may be used to recover GOS, products with high added value, from whey cheese. Significance and Impact of the Study β‐galactosidases are used in different industrial sectors. Therefore, the Trichoderma β‐galactosidase is a promising alternative for the production of GOS as prebiotic from the dairy effluents, contributing to the reduction in the environmental impact.