Production of 3-hydroxyalkanoic acid in crude cell extracts of P. putida U and P. putida U:: pha Z-. Cells grown to the stationary phase (16 h in 0.2NE2 medium + 15 mM octanoate) were harvested, resuspended to 1 mg total protein/ml in 100 mM Tris-HCl, pH 8, 0.5 mM MgCl2, and lysed by three passages through a French pressure cell. The production of PHA monomers was followed for P. putida U::pha Z- (filled triangle) and P. putida U (open triangle). Supernatants (250 μl) containing 3-hydroxyalkanoic acids were lyophilyzed and methanolyzed prior to analysis by GC. Data represent the average of two measurements.