Economical Di-Rhamnolipids Biosynthesis by Non-Pathogenic Burkholderia thailandensis E264 Using Post-Consumption Food Waste in a Biorefinery Approach

Rhamnolipids (RLs) are one of the most promising eco-friendly green alternatives to commercially viable fossil fuel-based surfactants. However, the current bioprocess practices cannot meet the required affordability, quantity, and biocompatibility within an industrially relevant framework. To circumvent these issues, our study aims to develop a sustainable biorefinery approach using post-consumption food waste as a second-generation feedstock. In-depth substrate screening revealed that food waste hydrolysate (FWH) was rich in readily assimilable carbohydrates, volatile fatty acids, and amino acids. The fermentative valorization of FWH as a sole carbon and energy source with Burkholderis thailandensis E264 in a bioreactor showed active RLs biosynthesis of up to 0.6-0.8 g/L (34-40 mg/g FWH) in a short duration (72 h). In terms of the kinetic parameters, the FWH-RLs outperformed other supplemented pure/waste streams. Interestingly, the recovered RLs had a long chain length, with Rha-Rha-C-12-C-14 being the predominant isoform and exhibiting a strong emulsification ability (E-24,E- 54.6%). To the best of our knowledge, this study is the first to prove bioreactor-level RLs production and their abundance in food waste. Moreover, the feasibility of this developed process could propel next-generation biosurfactants, lower waste burdens, and increase the industrial applicability of RLs, thereby significantly contributing to the development of a circular bioeconomy.

Automated summary

This study aims to develop a sustainable biorefinery approach using post-consumption food waste as a second-generation feedstock to produce renewable surfactants. The results showed that food waste hydrolysate (FWH) was rich in easily assimilable carbohydrates, volatile fatty acids, and amino acids. By utilizing FWH as the sole carbon and energy source, active biosynthesis of rhamnolipids (RLs) was achieved with high yield and long chain length, demonstrating the feasibility and potential of this process.