TABLE 3.

Isoprene production in different growth phases and in various strains^a

Growth phase	Concn (ng/ml/OD600) of isopreneb produced by the following strain:
	DSM 10	DSM 10/pHTdxs	DSM 10/pHTdxr	DSM 10/pHTdxsr
Early log	2.67 ± 0.16	3.73 ± 0.36	2.61 ± 0.22	3.45 ± 0.37
Mid-log	2.33 ± 0.24	3.29 ± 0.15	2.47 ± 0.16	3.27 ± 0.53
Late log	1.72 ± 0.09	1.92 ± 0.09	1.62 ± 0.01	2.31 ± 0.15

^aStrains were grown at 30°C in LB medium with shaking to OD₆₀₀ values of ∼0.2 for the early-log phase, ∼0.5 for the mid-log phase, and ∼1.0 for the late-log phase. Twenty micrograms of chloramphenicol per milliliter was added to the LB medium of the overexpression strains. During the course of the experiment, 10-ml aliquots were taken from the growing cultures and were transferred to 20-ml airtight vials. IPTG (1 mM) was added to the 10-ml cultures of the overexpression strains. These vials were incubated for one more hour with shaking at 30°C. Finally, the isoprene concentrations in the headspace were determined by GC-MS; then the OD₆₀₀ values of the cultures in the vials were taken using a spectrophotometer.

^bValues are averages ± standard deviations for three experiments.