Growth andβ-Glucan 10C3K Production by a Mutant ofAlcaligenes faecalisvar.myxogenesin Defined Medium

A defined medium was developed in which Alcaligenes faecalis var. myxogenes 10C3 mutant K produced a large quantity of β-glucan 10C3K. The medium contained 4% glucose together with 0.1% citrate, succinate or fumarate as the carbon source, 0.15% (NH4)2HPO4 as the nitrogen source and mineral salts. When NaNH4HPO4, KNO3 or urea was used at a concentration of 0.03% nitrogen as the sole nitrogen source, salts of organic acid were not needed in addition to glucose. In culture medium containing phosphate buffer (M/15, pH 6.5~8.0) large amounts of polysaccharide were formed and its yield from the 4% glucose added was about 50%. Thus, it was shown that polysaccharide production is enhanced greatly if a suitable pH for polysaccharide production is maintained during incubation.