Research Note: Purification and Characterization of Three Extraceullar Proteinases Produced by Pseudomonas fluorescens INIA 745, An Isolate from Ewe's Milk

摘要

Three proteinases were isolated form culture medium of Pseudomonas fluorescens INIA 745 and purified to homogeneity by a combination of Phenyl-Sepharose, DEAE-Sepharose, and Sephadex G-100 chromatography. Optimal temperature for enzymatic activity was 45 deg. C for all three proteinases. The pH optimum of proteinases I and II was found to be 7.0, while that of proteinase III was 8.0. Divalent metal ions like Cu~2+, Co~2+, Zn~2+, Fe~2+, and Hg~2+ were inhibitory to proteinase activity while Ca~2+, Mg~2+, and Mn~2+ had little or no inhibitory effect.