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

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. 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]) H 2 SO 4 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.

Production of acetone–butanol–ethanol (ABE) from concentrated yellow top presscake using Clostridium beijerinckii P260

“…At these YT sugar concentrations, ABE yields ranging from 0.39 to 0.57 were obtained (Table ). A detailed discussion of obtaining high yield has been provided in a previous article . ABE yields obtained in the present studies are similar to our previously reported yields (0.48–0.56) on YT fermentation.…”

“…Details of YT, its composition, pretreatment and hydrolysis have been published elsewhere . YT contained 45.1% (w/w) total sugars and 22.4% (w/w) lignin .…”

“…Details of YT, its composition, pretreatment and hydrolysis have been published elsewhere . YT contained 45.1% (w/w) total sugars and 22.4% (w/w) lignin . For fermentation studies, 8, 12.5 and 15 g quantities of dried YT presscake were suspended in 100 mL of 0.5% (v/v) sulfuric acid (Sigma Chemicals, St Louis, MO, USA) in 150 mL screw‐capped Pyrex™ glass bottles.…”

“…Other contributing factors that improve butanol or ABE process economics include use of agriculture‐based non‐food renewable feedstocks such as grasses, leaves, hay, corn stover, wheat straw, barley straw, etc . The cost of these feedstocks ($24–58 ton −1 ) is much lower than that of corn ($158 ton −1 ), corn starch, glucose or molasses ($100–200 ton −1 ; searched on Google). Other feedstocks that are economically attractive include carbohydrate‐containing wastes such as ‘food waste’.…”

“…One such feedstock is yellow top (YT) or Physaria fendleri presscake which is currently used for landfill. In a recent study, we used 60 and 100 g L −1 YT for butanol production employing C. beijerinckii P260 . Other factors that reduce the cost of fuel/biofuel production involve cutting edge science and technology .…”