OCTANOIC-ACID UPTAKE IN PSEUDOMONAS-PUTIDA U

Pseudomonas putida U grown in a chemically defined medium containing o ctanoic acid as the sole carbon source accumulated a homopolymer of po ly(3-hydroxyoctanoate) as intracellular reserve material, and metaboli zed the polymer during the late exponential phase of growth. Kinetic m easurement of the uptake of [1-C-14]octanoic acid by cells at 34 degre es C in 85 mM phosphate buffer, pH 7.0 showed linear uptake for at lea st 2 min and the calculated K-m and V-max were 100 mu M and 9 nmol min (-1) respectively. This transport system is constitutive, energy-depen dent, and is strongly inhibited by structural analogs of octanoic acid , by various fatty acids with a carbon length higher than C-5 and by c ertain phenyl derivatives.