Solid-state fermentation
Various agro-industrial residues such as cotton seed oil cake,
wheat bran and soya bean meal were used for evaluation their
potential as substrate in SSF for protease production. The
substrates were cut into small pieces, washed and soaked
overnight and water was drained off. SSF was carried out by
taking 200g of the substrates in saline bottles and the bottles
were plugged, wrapped and autoclaved at 121˚C for 15
minutes. After sterilization, the bottles were cooled and
inoculated with 5 discs of the fungal culture. The inoculated
bottles were incubated for 2 weeks at room temperature. After
incubation, 50 mL of 0.2 M phosphate buffer (pH 7.0) was
poured into the bottles. The bottles were kept in shaker for 30
minutes for allowing the buffer to extract the enzyme which
was followed by overnight incubation. The enzymes was
filtered and stored. The enzyme assay was carried out by
reading the absorbance at 650nm.