Abstract:

In this work, Plackett-Burman design and response surface methodology were applied to optimize the solid
medium containing soybean hull and distillers’ grains to produce cellulase by Neurospora crassa. Meanwhile, the
monosaccharide composition of fermentable sugars from the degraded product under optimal culture medium was analyzed
by gas chromatography. The results showed that the optimal medium was composed of 64% soybean hull, 34% distillers’
grains and 2% ammonia sulfate. Under the optimal condition, the activity of cellulase significantly was improved by
141.88%, from 1.17 IU/g to 2.83 IU/g, and the yield of reducing sugar was increased by 81.74%, from 9.91 g/100 g to
18.01 g/100 g compared to that obtained with the unoptimized medium. The major monosaccharide components of the
resulting fermentable sugars were glucose and xylose, respectively.

Key words: soybean hull, Neurospora crassa, cellulase, fermentable sugar, gas chromatography (GC)