Induced phase separation and recovery of 2,3-butanediol from fermentation broth

Authors: Stoklosa, Ryan; Latona, Renee

Submitted to: ACS Omega
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2025
Publication Date: 12/9/2025
Citation: Stoklosa, R.J., Latona, R.J. 2025. Induced phase separation and recovery of 2,3-butanediol from fermentation broth. ACS Omega. 10(50):62291-62299. https://doi.org/10.1021/acsomega.5c10210.
DOI: https://doi.org/10.1021/acsomega.5c10210

Interpretive Summary: The utilization of agricultural feedstocks can be expanded by using them for microbial fermentation to produce bio-based chemicals. The chemicals produced can supply and support a wide range of industries ranging from pharmaceuticals to commercial aviation. One chemical of interest is known as 2,3-butanediol (2,3-BDO). This chemical can be generated in fermentation processes by a number of different bacteria strains. The main drawback of producing 2,3-BDO through fermentation is the difficulty in recovering the component from the fermentation broth. Unlike ethanol which has a lower boiling point than water, 2,3-BDO has a much higher boiling point than water (177 degrees C). For this reason a typical distillation process is too energy intensive for the recovery of 2,3-BDO. However, 2,3-BDO can be recovered at standard room temperature and pressure by exploiting the phase separation properties of the chemical. This work shows that 2,3-BDO can be separated and recovered from fermentation broth by using non-toxic inorganic salts and organic solvents to force a phase separation between the aqueous fermentation broth and extract the 2,3-BDO into the low boiling point organic solvent. Up to an 85% recovery yield of 2,3-BDO from fermentation broth was achieved at a low salt loading of only 20% by weight. This information will be useful to chemical companies considering production of 2,3-BDO from agricultural sources and can provide new opportunities for utilization of agricultural products.

Technical Abstract: 2,3-Butanediol (2,3-BDO) is a promising platform chemical that can be utilized in a wide range applications including pharmaceuticals or as a building block for sustainable aviation fuel (SAF). Most 2,3-BDO production occurs using petroleum feedstocks, however, many bacteria species produce 2,3-BDO through microbial fermentation. A major drawback to bio-based 2,3-BDO production is the costly separation and recovery process. Due to the high boiling point of 2,3-BDO (177 degrees C) a traditional distillation process is too energy intensive. Other separation and recovery methods can be utilized that exploit the phase separation behavior of solutes in fermentation broth. This work evaluated the separation and recovery of 2,3-BDO from fermentation broth produced using molasses. The bacteria strain Paenibacillus polmyxa was cultivated in molasses media to generate 38.9 g/L of 2,3-BDO at a 1.5 L bioreactor scale. The fermentation broth was then subjected to induced phase separation for 2,3-BDO recovery using different inorganic salts and organic solvents. Ammonium sulfate in an equal volume mixture of ethanol/ethyl acetate produced high a 2,3-BDO recovery yield at 85.5% from the fermentation broth. This recovery yield was achieved at only a 20% ammonium sulfate loading indicating that low salt inputs can be utilized for this type of separation and recovery.