TABLE 6.

Effects of cphI gene and chloramphenicol on cyanophycin accumulation in A. calcoaceticus strain ADP1^a

Strain	Chloramphenicolb	CGP content (% of CDM)	CGP concn (g/liter)
A. calcoaceticus ADP1	−	38.0 ± 0.5	0.23 ± 9 × 10−3
	+	46.0 ± 0.6	0.28 ± 1 × 10−2
A. calcoaceticus ΔcphIc	−	14.3 ± 0.4	0.03 ± 16 × 10−4
	+	15.5 ± 0.5	0.01 ± 4 × 10−4

^aCells of A. calcoaceticus strain ADP1 and of the ΔcphI mutant were cultivated at 30°C in 250-ml Erlenmeyer flasks without baffles containing 100 ml of unbuffered MSM containing 10 mM ammonium sulfate as the nitrogen source; the initial pH was 7.3. In addition, the medium contained 75 mM arginine. At the end of the experiment the cells were harvested by centrifugation, and the cyanophycin content was analyzed. The data are means and standard deviations of three independent experiments.

^bChloramphenicol (2.5 μg/ml) was added after 24 h of cultivation, and cultivation was then continued for a further 24 h.

^cFor the cphI mutant, the medium also contained 50 μg of kanamycin per ml.