Yellow top (Physaria fendleri) presscake: A novel substrate for butanol production and reduction in environmental pollution

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. 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 including glucose, xylose, galactose, arabinose, and mannose. Then, the hydrolyzate was used to produce acetone-butanol-ethanol (ABE). Using 100 gL(-1) presscake (prior to pretreatment), 19.22 gL(-1) of ABE was successfully produced of which butanol was the major product. In this process, an ABE productivity of 0.48 gL(-1) h(-1) was obtained. These results are superior to glucose fermentation to produce ABE in which an ABE productivity of 0.42 gL(-1) h(-1) was obtained. Use of Yellow Top to produce butanol has the following advantages: (i) it is an economic feedstock and is expected to produce butanol economically; (ii) it avoids pollution concerns when not land filled; and (iii) rate of ABE production is not inhibited when fermented this substrate. It is suggested that the potential of this feedstock be further explored by optimizing process parameters for this valuable fermentation. (c) 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2767, 2019.