Extraction of milk-clotting enzyme produced by solid state fermentation of Aspergillus oryzae

Studies on the extraction of milk-clotting enzyme after solid-state fermentation (SSF) of wheat bran by a local strain of Aspergillus oryzae LSI were done. The extraction of the enzyme was found to be depended on different parameters like nature of extractant, soaking time, temperature etc. From different inorganic and organic extractants, calcium chloride (0.05%) and glycerol (40%) were found to be the best solvents for leaching out milk-clotting enzyme. The optimum volume of calcium chloride was 5 ml/g biomass. An extraction time of 180 min. at 30°C and 100 rpm was sufficient to extract out nearly 28% of the enzyme (2666.7 U/g biomass). Most of the enzyme (about 98.71%) was recovered in four repeated extractions.