Use of agro-industrial wastes for the production of a wild yeast enzyme with disintegration activity on plant tissues

Abstract

The objective of the present study was to develop a cost-effective medium, using agro-industrial wastes for the production of a polygalacturonase by Wickerhanomyces anomalus of interest in cassava starch industries. The effect of several raw agro-industrial wastes and others nutrients on polygalacturonase production by W. anomalus, were evaluated, in a reference fermentation medium, using statistical designs, by batch culture. The ability of the cell-free supernatant to extract cassava starch was evaluated. Lemon peel was the best inducer for the production of PGase. Statistical analysis of the data showed that lemon peel, Mg⁺² and PO₄HK₂ had significant effect on PGase production, and the others variables (yeast extract, Ca⁺², Fe⁺², amino acid and trace element solution) were no significant. PGase synthesis reached ~31 EUmL⁻¹ , in the OFM (glucose, lemon peel, urea, vitamins, KH₂PO₄ and MgSO₄), after 12 h of culture, at a lab scale bioreactor. PGase of W. anomalus, was able to disintegrate cassava tuber tissue, and the starch granules contained within the cells were released into the reaction medium. Lemon peel can be used as inducer for PGase production by W. anomalus, in a low cost culture medium, appropriate for the production of the enzyme at large scale.