Production of galactooligosaccharides and biosurfactants by Pseudozyma tsukubaensis using cassava wastewater as an alternative pre-inoculum medium

摘要

Yeasts from Pseudozyma genus are well known producers of important bioproducts, including biosurfactants and galactooligosaccharides. The objective of this study was to synthesize galactooligosaccharides, from lactose, by Pseudozyma tsukubaensis using cassava wastewater as the preinoculum medium to produce biosurfactants and β-galactosidase. P. tsukubaensis was able to grow and to produce biosurfactant on cassava wastewater, reducing the surface tension of medium to 26,09 mN/m after 36 hours in 30°C/150 rpm. Biomass production increase rapidly within 36 h of growth, and reached the maximum biomass weight in culture (2.55 g/L) at 48 h. The transgalactosylation activity of the yeast cells from 40% (w/w) lactose resulted in a maximum galactooligosaccharides production of 71,1 g/L and a yield of 17,78% (w/w) at pH 8,0 and 30°C in 24 hours. The results obtained in this study demonstrate for the first time the potential of P. tsukubaensis to produce galactooligosaccharides from lactose and its ability to growth in cassava wastewater producing biosurfactants in this medium. More research has been done to evaluate and optimize this process.