TABLE 4.

Activities of 3HBA and 4HBA dehydrogenases in H. pseudoflava and R. eutropha H16 grown on γ-butyrolactone under various culture conditions

Organism	Culture medium	Culture time (h)	Total protein concn (mg/ml)	Sp Act (U/mg) of:
				3HBA dehydrogenase	4HBA dehydrogenase
H. pseudoflava	Luria-Bertani medium	22	6.83	0.254	NDc
	Medium containing γ-butyrolactone (second step)a	48	3.21	2.75	0.064
	Medium containing 0.8 ml of γ-butyrolactone per liter (one step)b	96	1.06	ND	0.089
		108	2.31	0.031	0.170
		120	2.85	0.095	0.492
		132	3.13	0.183	0.531
		144	3.61	0.338	0.557
	Medium containing 0.8 g of 4HBA per liter (one step)b	96	1.54	0.075	0.030
		108	2.01	0.188	0.092
		120	2.47	0.231	0.162
		132	2.93	0.243	0.285
		144	3.01	0.277	0.369
R. eutropha H16	Luria-Bertani medium	22	3.81	1.69	ND
	Medium containing γ-butyrolactone (second step)a	48	4.33	3.15	0.071

^aCells grown in Luria-Bertani medium were transferred to PHA synthesis mineral medium containing γ-butyrolactone (2 ml/liter) plus ammonium sulfate (0.66 g/liter). 

^bPHA synthesis mineral medium also contained 0.66 g of ammonium sulfate per liter. 

^cND, not detected.