High performance amylolytic yeast strains isolation and identification for valorization of potatoes waste available in Burkina Faso

This study deals with isolation and identification of high amylolytic activity strains from potato wastes for biomass production. A total of twenty five (25) yeast strains were isolated using standard microbiological methods. Ten (10) strains were retained on the basis of their capacity to hydrolyze starch. Identification to species level of selected strains was performed with an API 20C AUX (Bio-Mérieux) according to the manufacturer’s instructions. Strain NOY 1 was identified as Candida utilis and had the best diameter of starch hydrolysis (24 mm) and the optimal enzymatic activity (1248 μM.l^-1.mn^-1). Optimal growth parameters of this strain were 30°C, pH 5; under these conditions, 5 g of starch/liter of medium were used for biomass production in an incubator at 150 rpm for 72 hours. The maximal biomass and protein content were obtained after 36 and 40 hours of incubation and were 5.65 g/l of medium and 0.53 g/g of dry weight respectively.