ESTIMATION OF LIPASE IN DAIRY PRODUCTS: IV. LIPOLYTIC ACTIVITY OF PSEUDOMONAS FLUORESCENS
The lipolytic activity of a strain of Pseudomonas fluorescens was investigated. Under the investigational conditions activity was greatest when the reaction medium was at approximately pH 8.9 at the start of the reaction period and when the reaction was carried out at approximately 42 °C. The optimum pH for activity by this enzyme was found to be between 8 and 9. This lipase is not specific for tributyrin but hydrolyzes tricaproin and tricaprylin as well, although with decreasing ease. Calcium chloride inhibited rather than enhanced the activity. Lipolytic activity was greater in nutrient broth-base media than in skim milk but the latter was more satisfactory with which to work. Lypolytic activity and fluorescence were not found to be related. Nutrient broth freed of carbohydrate by Escherichia coli growth and heat-sterilized stimulated production of fluorescence.