Pullulan production from deproteinized whey by Aureobasidium pullulans

Abstract

The production of pullulan from deproteinized whey by Aureobasidium pullulans P56 was investigated using an adaptation technique and a mixed culture system. The adaptation of A. pullulans and the mixed cultures of A. pullulans and/or Lactobacillus brevisX20, Debaryomyces hansenii 194 and Aspergillus niger did not increase the production of polysaccharide. Enzymic hydrolysis of lactose in deproteinized whey gave a higher polysaccharide concentration and polysaccharide yield than acidic hydrolysed lactose. Maximum polysaccharide concentration (11.0 +/- 0.5 g L-1), biomass dry weight (10.5 +/- 0.4 g L-1), polysaccharide yield (47.2 +/- 1.8%) and sugar utilization (93.2 +/- 2.8%) were achieved using enzyme-hydrolysed whey (pH 6.5) containing 25 g L-1 lactose and supplemented with K2HPO4 0.5%, L-glutamic acid 1%, olive oil 2.5%, and Tween 80 0.5%. In this case the pullulan content of the crude polysaccharide was 40%.