Screening of non-Ionic Surfactant for Enhancing Biobutanol Production.

This work deals with finding a suitable non-ionic surfactant which has high butanol capturing capacity and can be separated at a temperature close to room temperature and does not extract any intermediates or substrate (i.e., glucose). Importantly, it should be biocompatible, and its separation from the aqueous phase is not affected by other fermentation products. Hence, a pool of non-ionic Pluronic surfactants (L31, L61, L62D, L62LF, L62, L81, L92, L101, L121, L64, P65, P84, P104, P105) were selected for the study. Screening of the surfactant was done based on its hydrophile-lipophile balance (HLB) value, butanol capturing capacity (BCC), and cloud point temperature. Among the various surfactant investigated, L62D captured maximum amount of butanol (0.68 g/g of surfactant). Also, the cloud point temperature of L62D is close to room temperature (28.7 °C). Biocompatibility studies were carried out by conducting fermentation in presence of 3% L62D which resulted in 148% increase in butanol production as compared to control (without surfactant). Further, the fermentation products did not have strong influence on phase separation.