Production and Optimization of Protease Enzyme from Aspergillus terreus CJS-127 using Jatropha Seed Cake.

Soil samples from in and around Mysore and Surathkal were collected for
screening of fungi. The screening of fungi was done at three different pH 5.0,
7.0 and 9.0 using Czapek dox agar. The total microbial load was in the range
of 4x104 CFU/g at pH 5.0 to 2.14x108 CFU/g at pH 9.0. The fungal load at
pH 5.0 was in the range of 5x103-6.7x107 CFU/g. The fungal load at pH 7.0
was in the range of 1x105-9.4x107 CFU/g and the fungal load at pH 9.0 was
in the range of 9x105-8.4x107CFU/g. Maximum load of fungi was in the
samples screened at pH 5.0. The isolated fungi were screened for protease
production and Aspergillus terreus CJS-127 was selected for optimization of
protease production. The optimization of protease production was done by
O-FAT method by selecting 5 parameters. Based on O-FAT result the
maximum protease production was 59,515 U/g, on 5 days of incubation, at
pH 7.0, with inoculum of 107 spores/ml, at 60% moisture content and at
30°C. Addition of external carbon and nitrogen sources to Jatropha seed
cake did not enhance the protease production. Further optimization of
protease production was done by Taguchi’s method. Taguchi is a wellknown
technique that provides systematic and efficient methodology for
design optimization. The primary advantages for design of experiments using
Taguchi’s technique include simplification of experimental plan and
feasibility of study of interaction between different parameters. The
cultivation conditions optimized for protease production by Taguchi method
were incubation period- 4 days, inoculum size- 107 spores/ml, moisture
content- 50% and incubation temperature- 25°C. Under these optimized
conditions, the maximum protease production was 1,02,832 U/g.