Pentose-rich hydrolysate from oil palm empty fruit bunches for β-glucan production using Pichia jadinii and Cyberlindnera jadinii

Abstract

Pentose-rich hydrolysate obtained from dilute acid pretreatment of oil palm empty fruit bunches was successfully consumed by pentose-consuming yeasts: Cyberlindnera jadinii (Cj) and Pichia jadinii (Pj). Nitrogen supplementation and no additional detoxification step were required. Pj produced 5.87 g/L of biomass using a C/N ratio of 14 after 120 h of fermentation, with xylose consumption of 71%. Cj produced 10.50 g/L of biomass after 96 h of fermentation with C/N ratio of 11.5, with maximum xylose consumption of 85%. β-glucans, high value-added macromolecules, were further extracted from the yeast biomass, achieving yields of 3.1 and 3.0% from Pj and Cj, respectively. The isolated polysaccharides showed a chemical structure of β-(1,3)-glucan with residues of other molecules. Additionally, β-(1,6) branches seems to have been broken during isolation process. Further studies assessing β-glucans production at industrial scale should be carried out looking for nitrogen sources and optimizing the β-glucan isolation method.

Keywords: Cyberlindnera jadinii; Dilute acid pretreatment; Oil palm empty fruit bunches; Pichia Jadinii; β-glucan.