Influence of growth stage on activities of polyhydroxyalkanoate (PHA) polymerase and PHA depolymerase in Pseudomonas putida U

Table 1 Granule-bound PhaC activities of various P. putida mutants

Strain	Reference	PHA granule phasins		Granule-bound PhaC activity (U/mg PhaC)
		PhaF	PhaI
P. putida U	[16]	+	+	40.2
P. putida::phaZ^-	[16]	+	+	44.9
P. putida BMO1	[32]	+	+	42.2
P. putida BMO1-42	[32]	-	-	12.7
P. putida GPo1	[15, 23]	+	+	42.3
P. putida GPG-Tc-6	[13, 23]	-	+	38.0
P. putida GPo1001	[31, 23]	+	-	29.5

Assay conditions: 100 mM Tris-HCl, pH 8, 1 mg/ml BSA, 0.5 mM MgCl₂, 0.0125-0.25 mM R- 3-hydroxyoctanoyl-CoA and 0.2 μg/ml granule-bound PhaC (granules isolated after growth for 10 hours). Initial activity was measured spectrophotometrically (A 412) by following release of CoA using DTNB. PhaC amounts were estimated by densitometric scanning of SDS-polyacrylamide gels.

ISSN: 1471-2180