This research investigates a two-stage fermentation process using the oleaginous yeast Lipomyces starkeyi to produce microbial lipids for biodiesel production. The study compares three different medium compositions: yeast extract peptone dextrose (YPD) medium, orange peel (OP) hydrolysate, and a 50:50 mixture of YPD and OP hydrolysate. The two-stage fermentation process significantly enhanced lipid content (by 18.5-27.1%) and lipid titer (by 13.6-77.8%) compared to one-stage fermentation. The microbial lipids produced were primarily composed of palmitic acid (33-38%) and oleic acid (46-48%), making them suitable for biodiesel production. The study shows that using a mixture of commercial medium and lignocellulosic biomass hydrolysate offers a promising balance between operating costs and lipid production.
The research contributes to environmental sustainability in several ways: Addresses current dilemmas of energy shortages, organic waste management, and environmental impacts of fossil fuels Provides a pathway for converting organic waste (orange peel) into renewable biofuel Offers several advantages over traditional biodiesel: lower production costs, increased sustainability, and reduced land use for oil crops Demonstrates a waste-to-resource approach that could help manage large quantities of lignocellulosic biomass waste in global megacities Contributes to developing more economical fermentation technologies for microbial lipid production, making biodiesel production more viable and sustainable
The researchers used the following approach: