# Biosurfactants Contribute to Distiller’s Corn Oil Recovery during Ethanol Production

## TL;DR

This study explores using biosurfactants to improve oil recovery during ethanol production, finding them effective and eco-friendly.

## Contribution

The first study to investigate biosurfactants for distiller’s corn oil recovery in ethanol production.

## Key findings

- Both mono-RML and di-RML biosurfactants increased total oil recovery from fermentation.
- Di-RML improved DCO recovery from thin vinasse as effectively as the chemical surfactant Tween 80.
- Di-RML reduced reaction medium viscosity during key ethanol production steps.

## Abstract

Distiller’s
corn oil (DCO) is an important coproduct of
the ethanol industry. However, this oil is partially emulsified in
the fermentation medium and adheres to solid particles during ethanol
production. The addition of surfactants can facilitate the DCO removal.
This study is the first to investigate the use of biosurfactants,
biodegradable molecules with demulsifying properties, for DCO recovery.
For this, two rhamnolipid (RML)-type biosurfactants, one mono-RML-rich
mixture and the other, di-RML, both produced using DCO as a carbon
source, were added into ethanol production at a concentration of 0.5
g/L. The chemical surfactant Tween 80 was also added as a positive
control. Both biosurfactants increased the total oil recovery (thin
vinasse and solids); moreover, di-RML also enhanced the DCO recovery
from thin vinasse as well as Tween 80. Both surfactants did not impact
the ethanol productivity. Additionally, di-RML reduced the viscosity
of the reaction medium during liquefaction and simultaneous saccharification
and fermentation. These findings suggest that di-RML is a viable and
eco-friendly alternative to chemical surfactants, promoting enhanced
oil recovery and improved process efficiency in the biorefinery and
circular economic context.