Table 2.

Effect of different modification methods on cellulase production. Filter paper activity (U/g) measured on day 1, 3 and 5. The modified and non-treated wheat straw were fermented by A. niger with a liquid to solid ratio of 7.5:1 at 28 °C in a static incubator.

Time (day)	Non-treated	Autoclave	Diluted acid	Acid soaking
0	0 ± 0	0 ± 0	0 ± 0	0 ± 0
1	4.37 ± 1.37	4.33 ± 0.38	8.65 ± 0.58	7.51 ± 1.20
3	5.83 ± 0.68	9.51 ± 1.64	10.2 ± 0.13	5.11 ± 1.08
5	3.89 ± 0.96	5.55 ± 0.54	4.43 ± 0.07	4.73 ± 0.93