Effect of some nutritional and environmental factors on extracellular protease production by Pseudomonas SP.B-25

Abstract

SUMMARV Fortification of the 1 % tryptone basal medium with 0.25 % yeast extract resulted in 2.6-fold increase in protease production by Pseudomonas sp.B-25. Tryptone yeast extract in the medium could not be substituted by other equivalent media ingredients. Of the various inorganic salts incorporated in the modified basal medium Cl% tryptone + 0.25 % yeast extract), addition of 0.2 % potassium phosphate salts elicited maximum enzyme production. However, none of the fermentable sugars tried as supplements to the formulated tryptone-yeast extract-phosphate (TYEP) medium proved useful. Maximum protease production was observed in TYEP medium at pH 7.0 when inoculated with 2.5 % of 24 hr old broth culture and incubating at 22° C for 48 h on a gyratory shaker. The protease production by Pseudomonas sp.B-25 was found to be initiated in the early logarithmic growth phase and reached the maximum when the culture was in the decline phase of growth.