Fungal Upgrading of Straw for Thermoplastics
Applied Biochemistry and Biotechnology Vol. 113–116, 2004
Copyright © 2004 by Humana Press Inc.
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Fungal Upgrading of Wheat Straw
for Straw-Thermoplastics Production
Idaho National Engineering and Environmental Laboratory,
Idaho Falls, ID 83415-2203,
E-mail: email@example.com; and
Washington State University,
Pullman, WA 99164-1806
Combining biologic pretreatment with storage is an innovative approach
for improving feedstock characteristics and cost, but the magnitude of
responses of such systems to upsets is unknown. Unsterile wheat straw stems
were upgraded for 12 wk with Pleurotus ostreatus at constant temperature to
estimate the variation in final compositions with variations in initial mois-
ture and inoculum. Degradation rates and conversions increased with both
moisture and inoculum. A regression analysis indicated that system perfor-
mance was quite stable with respect to inoculum and moisture content after
6 wk of treatment. Scale-up by 150× indicated that system stability and final
straw composition are sensitive to inoculum source, history, and inoculation
method. Comparative testing of straw-thermoplastic composites produced
from upgraded stems is under way.
Index Entries: Fungal upgrading; engineered storage; biological prepro-
cessing; Pleurotus ostreatus; straw composite.
Agricultural crop residues are a valuable renewable biomass resource.
In 1999, American farmers harvested 53,909,000 acres of wheat (1). The
straw from this acreage of wheat represents >50 million t annually. Cur-
rently, some of the straw is harvested (baled) for use as livestock bedding
or low-grade animal feed. However, these low-value uses provide only a