Location: Bioenergy ResearchTitle: Yellow top (Physaria fendleri) presscake: a novel substrate for butanol production and reduction in environmental pollution
Submitted to: Biotechnology Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2019
Publication Date: 12/19/2018
Citation: Qureshi, N., Harry-O'Kuru, R.E., Liu, S., Saha, B. 2018. Yellow top (Physaria fendleri) presscake: a novel substrate for butanol production and reduction in environmental pollution. Biotechnology Progress. 35(3):e2767. https://doi.org/10.1002/btpr.2767.
Interpretive Summary: Butanol is a superior fuel than ethanol. As compared to ethanol, it contains 33% more energy and burns cleaner thus reducing air pollution. During World Wars I & II, butanol was produced from corn using a bacterial strain. Currently corn prices are high which makes butanol production uneconomical by fermentation. It can also be produced from agricultural residues upon hydrolysis. In the present studies we explored use of yellow top presscake. Yellow top is a plant that belongs to mustard family and its seed is used to produce oil. Currently, yellow top press cake is used for land fill that causes pollution. In the present studies yellow top presscake was pretreated with dilute sulfuric acid followed by enzymatic hydrolysis to release sugars for butanol fermentation. We were able to produce butanol from this feedstock with the comparable titer as using corn or glucose. Use of this feedstock for butanol fermentation will avoid air pollution while land fill and while using it as a gasoline substitute. Development of production of butanol from yellow top presscake would benefit yellow top farmers, gasoline consumers and reduce air pollution.
Technical Abstract: Yellow top (Physaria fendleri) is a plant that belongs to the mustard family. This plant is used to produce seeds that are rich in hydroxy oil. After extraction of oil, the presscake is land-filled which is an environmental pollution concern. The seedcake is rich in polymeric sugars and can be used for various bioconversions. For the present case, the seedcake or presscake was hydrolyzed with dilute [0.50% (v/v)] H2SO4 and enzymes to release sugars such as glucose, xylose, galactose, arabinose and mannose. Then the hydrolyzate was used to produce acetone butanol ethanol (ABE). Using 100 gL-1 presscake, 19.22 gL-1 ABE was successfully produced of which butanol was the major product. In this process an ABE productivity of 0.48 gL-1h-1 was obtained. These results are superior to glucose fermentation to produce ABE in which an ABE productivity of 0.42 gL-1h-1 was obtained. It is suggested that the potential of this feedstock be further explored by optimizing process parameters for this valuable fermentation.