9-09: Ability of alkali and enzymatically hydrolyzed prairie cordgrass to support fungal pullulan production

Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Eric L. Grimm and Thomas P. West, Biology and Microbiology, South Dakota State University, Brookings, SD
The polysaccharide gum pullulan has a variety of industrial applications and is commercially available. It has not been established whether pullulan could be elaborated by the fungus Aureobasidium pullulans utilizing glucose released from hydrolyzed plant biomass. Prairie cordgrass is a potential source of plant biomass since it can produce a high yield with minimal fertilizer input. Prairie cordgrass contains about 30% cellulose which could be hydrolyzed to glucose. Glucose is a known substrate for fungal pullulan production. In this investigation, it was determined whether A. pullulans ATCC 42023 could utilize an alkali and enzymatically treated prairie cordgrass hydrolysate to support pullulan synthesis. The hydrolysate was prepared by mixing the ground, dried grass with 7% sodium hydroxide and then autoclaving the mixture (10% solids) at 121oC for 30 minutes. The hydrolyzed cordgrass remaining after 7% sodium hydroxide treatment was collected by filtration, washed and dried. The treated grass was subsequently hydrolyzed using both cellulase and cellobiase for 48 hours at 40oC. The resultant filtrate was used for the fungal growth medium. The fungal cells were grown for 168 hours at 30oC in a phosphate-buffered medium (pH 6.0) containing the cordgrass hydrolysate. Culture medium was sampled and subjected to centrifugation to pellet the cells. The pullulan in the resultant supernatants was precipitated by alcohol and determined gravimetrically. The highest pullulan level was elaborated by ATCC 42023 after 168 hours of growth on the hydrolysate-containing medium. Overall, A. pullulans was capable of utilizing the alkali and enzymatically hydrolyzed prairie cordgrass to produce pullulan.
See more of: Poster Session 2
See more of: General Submissions