Yeasts with amylolytic, lipolytic and proteolytic activities isolated from mango (Mangifera indica L.) fruits

Yeasts were isolated from mangoes, an untapped resource for yeast bioprospecting. Fruit washings from three varieties of ripe healthy mangoes, namely: "Kalabaw", "Indian" and "Piko" were spread plated onto yeast extract malt extract agar (YMA) and ethanol sulfide agar (ESA) supplemented with streptomycin and biphenyl. Two hundred seventeen yeasts were isolated from six mango samples. The isolates were screened for amylase, lipase and protease on starch agar, Sierra's medium with Tween 80 and casein agar, respectively. Yeasts that produced lipase numbered 100 while 51 produced amylase and 46 produced protease. Phenotypic identification of 29 yeasts which had moderate to high enzymatic activities was done and 11 were subjected to D1/D2 26S ribosomal RNA gene (D1/D2 26S rRNA) sequencing. The yeasts with amylolytic, lipolytic and/or proteolytic activities which were identified include: Aureobasidium pullulans var. melanogenum, Aureobasidium sp., Candida haemulonii, Cryptococcus aerizts, C. flavescens, Cryptococcus sp. and Rhodosporidium paludigenum. The study provided a snap shot of the diversity of the yeast microflora in the surface of ripe healthy mangoes from the Philippines and it has identified and preserved enzyme-producing yeast strains with possible commercial use.