Volume 6, Issue 1, February Issue - 2018, Pages:131-141
Authors: Milky Goyal, Rouf Ahmad Dar,Urmila Gupta Phutela
Abstract: Protease is one of the most important groups of commercially produced enzymes. This study was aimed at the optimization and kinetics of protease production from poultry dropping based biodigested slurry by Humicola fuscoatra MTCC 1409. Four significant variables (pH, temperature, slurry concentration and inoculum concentration) were considered for optimization both by one variable at a time approach and response surface methodology. The maximum protease production in the poultry dropping based biodigested slurry was (531±1.37 U g-1) under the optimum conditions of pH (5), temperature (40°C), slurry concentration (25%) and inoculum concentration (10%). The protease production was found to be 3.38 fold higher under optimized conditions as compared to the non-optimized ones. The thermal inactivation of protease produced from biodigested slurry was investigated kinetically within temperature range of 30-70°C. The irreversible inactivation was well described by first order kinetics with k values increasing between 0.0028 to 0.0071 min-1 and t1/2 decreasing from247.70 to 98.10 mins. At higher temperature, there was significant decrease in residual activity. The activation energy, enthalpy, Gibbs free energy and entropy range calculated on the basis of residual activity experiments conducted at temperature range of 30-70°C was found to be 21.29, 18.44 to 18.78 kJ mol-1, 89.01 to 98.47 kJ mol-1 and -0.23334 to -0.23181 kJ mol-1 respectively, suggesting the thermostability of enzyme. This is first report on optimization, kinetics and determination of thermodynamic parameters of protease production by Humicola fuscoatra MTCC 1409 from poultry dropping based biodigested slurry.