Treatment and Valorization of Palm Oil Mill Effluent through Production of Food Grade Yeast Biomass

Abstract

Palm oil mill effluent (POME) is high strength wastewater derived from processing of palm fruit. It is generated in large quantities in all oil palm producing nations where it is a strong pollutant amenable to microbial degradation being rich in organic carbon, nitrogen, and minerals. Valorization and treatment of POME with seven yeast isolates was studied under scalable conditions by using POME to produce value-added yeast biomass. POME was used as sole source of carbon and nitrogen and the fermentation was carried out at 150 rpm, 28 ± 2°C using an inoculum size of 1 mL of 106 cells. Yeasts were isolated from POME, dump site, and palm wine. The POME had chemical oxygen demand (COD) 114.8 gL−1, total solid 76 gL−1, total suspended solid (TSS) 44 gL−1 and total lipid 35.80 gL−1. Raw POME supported accumulation of 4.42 gL−1 dry yeast with amino acid content comparable or superior to the FAO/WHO standard for feed use SCP. Peak COD reduction (83%) was achieved with highest biomass accumulation in 96 h using Saccharomyces sp L31. POME can be used as carbon source with little or no supplementation to achieve waste-to-value by producing feed grade yeast with reduction in pollution potential.