Cultivation of Rhodotorula Toruloides Using Palm Oil Mill Effluent: Effect on the Growth, Lipid Production, and Waste Removal

Abstract

Using Palm Oil Mill Effluent (POME) as a medium for culturing oleaginous yeast is advantageous for simultaneous lipid production and waste removal. The organic compounds in POME can be utilised as a nutrient source for yeast growth. Rhodotorula toruloides yeast was cultivated in filtered and unfiltered raw POME as growth media in this study. The yeast growth, pH changes in media, lipid production and removal of chemical oxygen demand (COD) of Rhodotorula toruloides cultivated in POME were examined and compared to Rhodotorula toruloides grown in yeast peptone dextrose (YPD) control media. The COD level of filtered POME was reduced by nearly 50% after filtration. The biomass concentration of Rhodotorula toruloides in filtered POME surpassed the other media in the following order: filtered POME > YPD > unfiltered POME (152 mg/ml > 121 mg/ml > 37 mg/ml). The filtered POME was found favourable for yeast growth due to the minimal amount of colloidal particles and suspended solids. Meanwhile, the lipid production (4.51 %) in filtered POME was 4.8-fold higher than in control media. The water analysis indicated about 43% of COD reduction, signifying the ability of Rhodotorula toruloides to utilise nutrient components present in POME for growth. This study provides insightful knowledge on the utilisation of oleaginous yeast for simultaneous green waste disposal and sustainable microbial oil production.