EUBCE 2026 - Roberto ALBERGO - Enhancing Carbon Recovery in SCO and Biomethane Production through Sequential Fermentation and Anaerobic Digestion of Residual Streams

Enhancing Carbon Recovery in SCO and Biomethane Production through Sequential Fermentation and Anaerobic Digestion of Residual Streams

Short Introductive summary

In the context of circular bioeconomy, efficient valorisation of residual streams is essential to improve sustainability and carbon utilization. In a previous study, microbial oil production from sugarcane molasses supplemented with crude glycerol was optimized and scaled up, leaving a residual broth rich in unconsumed carbon sources. In this work, the residual stream (~50 g/L crude glycerol, ~10 g/L mannitol) was further valorised through a secondary fermentation using Rhodotorula glutinis. Complete glycerol consumption was achieved, while mannitol was largely unutilized, indicating substrate selectivity. Biomass yield reached ~0.4 g/g glycerol, with ~25% lipid accumulation. This sequential fermentation strategy enhances carbon recovery and enables efficient production of single-cell oils (SCOs). The final exhausted broth was further treated by anaerobic digestion for biogas production, allowing additional energy recovery. Overall, this integrated approach maximizes carbon valorisation and supports the development of sustainable and economically viable biorefinery processes.

R. Albergo, ENEA - Trisaia Research Center, Rotondella, ITALY
C. Limonti, ENEA - Trisaia Research Center, Rotondella, ITALY
N. Turano, ENEA - Trisaia Research Center, Rotondella, ITALY
A. Caporusso, ENEA - Trisaia Research Center, Rotondella, ITALY
V. Valerio, ENEA - Trisaia Research Center, Rotondella, ITALY
E. Viola, ENEA - Trisaia Research Center, Rotondella, ITALY
I. De Bari, ENEA - Trisaia Research Center, Rotondella, ITALY