INHIBITION OF A MIXTURE OF CRUDE PSEUDOMONAS LIPASES BY SELECTED EMULSIFIERS

Four commercial emulsifiers, sodium oleate, sodium stearate, sodium st earoyl-2-lactylate, and calcium stearoyl-2-lactylate, were evaluated f or their effectiveness as inhibitors of Pseudomonas lipases. Each emul sifier was incubated at 0.5, 1.0, and 2.0% concentrations with the ind ividual as well as a mixture of the crude lipase extracts obtained fro m three Pseudomonas spp. (P. fluorescens, P. putida, and P. cepacia), in reconstituted nonfat dry milk (10%) for 30 min. At a 2% concentrati on, all emulsifiers tested were potent inhibitors (100%) of lipase act ivity. The effectiveness of lipolysis inhibition declined with decreas ing emulsifier concentration. Sodium oleate demonstrated significant ( P < 0.05) lipolysis inhibition at a 1% concentration regardless of ini tial lipase level. Synergism in inhibiting lipolytic activity between these selected emulsifiers was not evident.