A facile reactor process for producing 7,10-dihydroxy-8(E)-octadecenoic acid from oleic acid conversion by Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa strain PR3 (NRRL B-18602) converts oleic acid to a novel compound, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD). The bioconversion was scaled up in a 7-l bench-top, stirred-batch reactor to produce DOD for testing of potential industrial uses. Aeration was supplied continuously from the top through two ports on the headplate and periodically through a bottom sparger, in conjunction with the use of marine impellers for agitation. This unique aeration arrangement maintained the dissolved O2 concentration in the 40-60% range during the period of maximal bioconversion and it also avoided excessive medium foaming during the reaction. Furthermore, the level of dissolved O2 in the first 24 h of reaction played an important role in the initial rate of DOD production. DOD production reached a plateau after 72 h with a yield up to 100 g (or 50% recovery) from a total of 9 l medium from two reactors run simultaneously. The final culture broth was processed using newly adapted procedures in the pilot plant that included crystallization of DOD from ethyl acetate solution at -15 degrees C. The newly developed bioprocess will serve as a platform for the scale-up production of other value-added products derived from vegetable oils and their component fatty acids.