Exploiting Landfill-Derived Rhodotorula mucilaginos a for Simultaneous Biofuel Synthesis and Leachate Remediation

Abstract

Landfill leachate, a complex mixture resulting from decomposing waste, contains suspended and dissolved organic and inorganic compounds. This nutrient-rich environment facilitates the growth of diverse microbial communities that can utilize these compounds for sustenance. Rhodotorula mucilaginosa is a yeast with great potential in the field of biotechnology due to its ability to utilize diverse substrates and its strong resistance to environmental stress. This study was aimed at investigating the potential of R. mucilaginosa, a yeast strain isolated from landfill environments, for biofuel production and simultaneous pollutant reduction in leachate. Batch cultivations were conducted using leachate as the sole growth medium. Cultivation was conducted for 2, 4, 6, and 8 days to analyse the lipids from R. mucilaginosa biomass and the degradation of pollutants in the resulting leachate. Additionally, the fuel properties were determined to assess the quality of the biodiesel produced from R. mucilaginosa lipids. The obtained quality was compared with the American Society for Testing and Materials (ASTM D6751), the Indonesian National Standard (SNI 8968:2021), and the Fatty Acid Methyl Ester (FAME) derived from palm oil. Results demonstrated significant lipid accumulation by R. mucilaginosa, reaching 19% (w/w) after 144 hours (6 days) of cultivation. Gas Chromatography-Mass Spectrometry (GC-MS) analysis revealed a FAME profile dominated by C16 and C18 fatty acids, suitable for biodiesel production. Concurrently, substantial reductions in leachate pollutant levels were observed, with decreases of 40.43% for Chemical Oxygen Demand (COD), 86% for phosphate, 90% for ammonia, 53% for nitrate, and 64% for nitrite. These findings highlight the potential of R. mucilaginosa, isolated from landfill leachate, as a promising bioremediation agent for wastewater treatment and a sustainable source of lipids for renewable energy production.

Keywords

• rhodotorula mucilaginosa
• lipid
• leachate
• biofuel
• pollutant