title: Agar-like polysaccharide produced by a pseudomonas species: production and basic properties.
abstract: A new species of Pseudomonas was isolated that produced copious amounts of an exocellular heteropolysaccharide (PS-60) after incubation for 3 days at 30 degrees C in media containing 3% glucose as a carbon source. The polysaccharide was composed of approximately 46% glucose and 30% rhamnose and, in addition, contained 21% uronic acid and 3% O-acetyl. Upon deacetylation by a mild alkaline treatment, PS-60 produced a brittle, firm, and optically clear gel. This gelling property was thermoreversible. The PS-60 gel exhibited excellent heat stability that withstood autoclaving (i.e., 121 degrees C for 15 min) for several cycles. The gel strength, melting point, and setting point of the polysaccharide were controlled primarily by the concentration of cations. PS-60 was not affected by a variety of enzymes. The results of tests involving various culture media and biochemical test media indicate that PS-60 is an excellent alternative gelling agent to agar.
authors.affiliation: Kelco Division, Merck & Co., Inc., San Diego, California 92123.
authors.forename: K S
authors.initials: KS
authors.lastname: Kang
authors.forename: G T
authors.initials: GT
authors.lastname: Veeder
authors.forename: P J
authors.initials: PJ
authors.lastname: Mirrasoul
authors.forename: T
authors.initials: T
authors.lastname: Kaneko
authors.forename: I W
authors.initials: IW
authors.lastname: Cottrell