Yasuhiro Nohata

Complete defined medium for large-scale production of polysaccharide bioabsorbent from Alcaligenes latus B-16

Abstract A complete medium not including yeast extract for industrial production of a biopolymer by Alcaligenes latus B-16 was developed. Glycine and iron ion were effective substitutes for yeast extract.

Culture conditions for production and purification of bioabsorbent from Alcaligenes latus B-16☆

Glucose and sucrose were favorable carbon sources for the production of bioabsorbent from Alcaligenes latus B-16. Yeast extract at a concentration of 0.5% was also an effective medium for growth. Biopolymers from A. latus B-16 were purified, and the biopolymers were separated into two types of biopolymers: a high-molecular weight component (acid-biopolymer) and a low-molecular weight component (neutral-biopolymer). These two types of biopolymers were shown to be homogeneous on electrophoresis and GPC (Gel Permeation Chromatography on HPLC). The high-molecular weight component was bioabsorbent, and was able to absorb water at more than 1,000 times its own weight. The total yield of acid- and neutral-biopolymers from A. latus B-16 was 20–25 g (dry weight) per liter of culture broth, and they were produced at a ratio of 20:1 (acid:neutral).

Structural studies of a neutral polysaccharide produced by Alcaligenes latus

Abstract The structure of a neutral polysaccharide, isolated from the culture medium of Alcaligenes latus strain B-16, has been investigated by monosaccharide analysis, methylation analysis, one-(1D) and two-dimensional (2D) 1 H and 13 C NMR spectroscopy, and enzymatic digestion, and by MALDI-TOF-MS and LC-MS analyses of oligosaccharides isolated from a partial acid hydrolysate. The polysaccharide has the linear disaccharide repeating unit →2)-α- D-Man p-(1→3)-α- L-Fuc p-(1→

Physical characteristics of the acid biopolymer (bioabsorbent) from Alcaligenes latus B-16☆

Abstract Alcaligenes latus B-16 produces two extracellular biopolymers. One is a high molecular weight (5 × 109) acid-polysaccharide which contains uronic acid and is a bioabsorbent. It also has other interesting characteristics. For example, its rheological analysis revealed that it pseudoplastic and has a higher apparent viscosity than xanthan gum at more than twice the concentration. Its apparent viscosity is constant in the temperature range of 5°C to 80°C, and it is stable during storage. Moreover, it showed the excellent advantage of good water retention capacity for paper making and super water retention capacity through sand even at 70°C.

Preparation of biopolymers with different viscosities by heat treatment under alkaline conditions

Alcaligenes latus B-16 produces an extracellular biopolymer that exhibits high viscosity. The biopolymer (B-16 biopolymer) was recovered by adding an organic solvent into A. latus B-16 culture broth. B-16 biopolymers with different viscosities were prepared by heat treatment under alkaline conditions.