Co-utilization of sugars and lignin-derived compounds by Rhodococcus jostii RHA1 for lipid production

Aromatic-rich lignin degradation compounds resulting from the pretreatment of lignocellulosic biomass pose barriers to the efficient uptake of sugars by many microorganisms. On the other hand, these aromatic compounds are potential substrates for biosynthesis of many high value products. However, their direct utilization remains a challenge. Rhodococcus jostii RHA1 is a versatile strain, which can utilize a wide range of plant-derived compounds, such as aromatics and carbohydrates, and accumulate lipid under nitrogen-limited condition. In this study, the capabilities of R. jostii RHA in growing media containing representative lignin degradation compounds from pretreatment were investigated. The utilization profiles of sugars along with lignin-derived compounds were reported. The potential inhibitory effects of lignin-derived compounds on the lipid production were also studied. This study provides insights into the catabolism of aromatic compounds by R. jostii RHA1 and biosynthesis of lipid when fermentable sugars are used as co-substrates.