Gate-to-gate life cycle assessment of sophorolipid production with Starmerella bombicola: Impact of cultivation conditions and scale-up on carbon footprint.

Sophorolipid, a biosurfactant which can be fermentatively produced by the yeast Starmerella bombicola using sugars and lipids as carbon sources, exhibits several advantageous properties over synthetic detergents, such as biodegradability and low toxicity. While some life cycle assessment (LCA) studies have been reported to evaluate the environmental impact of sophorolipid production, carbon footprint estimations remain limited. In this study, we combined small-scale experimental data with large-scale simulation data to estimate the carbon footprint of the fermentative production of sophorolipid by S. bombicola. Our LCA analysis estimated that sophorolipid production in a 1-L bench-top bioreactor emits 685 kg CO2 eq per kg of product. A scale-up simulation of the carbon footprint resulted in a marked decrease in CO2 emission from sophorolipid production in larger scales. Through sensitivity analysis, we identified key hotspots in the production process, particularly related to production scale.