TABLE 2.

Specific activities of relevant enzymes in recombinant strains of E. coli JM109 strains harboring different plasmids^a

Strain	Sp act (U/mg of protein)
	Buk	Ptb	PHA synthase
JM109(pJC7)	18	3.0	NDb
JM109(pBPP1)	10	3.8	0.1
JM109(pBPP2)	15	2.5	ND
JM109(pBPha)	ND	ND	0.5

^aStrains were cultivated in 300-ml Erlenmeyer flasks containing 50 ml of LB medium with 1 mM isopropyl-β-d-thiogalactopyranoside and 100 mg of ampicillin per liter at 37°C and at 200 rpm for 24 h. 

^bND, not detected.