TABLE 4.

The β-ketothiolase specific activity of R. eutropha strains was altered by changes at the phaB1 locus^a

Strain	Genotype	Sp act (U/mg)
H16	Wild type	0.7 ± 0.1
Re2112	ΔphaB1ΔphaB2	2.7 ± 0.2
Re2115	ΔphaB1ΔphaB2ΔphaB3	2.9 ± 0.3
Re2139	Re2115::phaB1	0.7 ± 0.2
Re2140	Re2115::phaB2	2.3 ± 0.2
Re2143	Re2115::phaB3	1.0 ± 0.1

^aAll strains were grown in duplicate, and each sample was measured twice (n = 4 for each strain). Measurements were made with soluble lysate fractions. Values are reported as means ± SD. One unit of activity is defined as the amount of enzyme needed to convert 1 μmol acetoacetyl-CoA to product per minute at 25°C.