Biomedical subjects

R F ANDERSON

Publications and source records attributed to R F ANDERSON.

13 recordsLinked to original sources

PubMed1965

PRODUCTION OF 2-KETOGLUCONIC ACID BY SERRATIA MARCESCENS.

Production of 2-ketogluconic acid from glucose by fermentation with Serratia marcescens NRRL B-486 was studied in 20-liter stainless-steel fermentors. Conditions for 2-ketogluconic acid production included the following: glucose-salt medium, aeration rate of 0.75 volumes per volume per minute, agitation rate of 400 rev/min, temperature of 30 C, CaCO(3) to neutralize the acid formed, and a 5% (v/v) inoculum. Foaming was controlled with an antifoam agent added at intervals during the fermentation. When 120 g per liter of glucose were supplied, 95 to 100% yields of 2-ketogluconic acid were obtained in 16 hr. Larger amounts of glucose could be used in the fermentation provided that the carbohydrate was fed continuously. Continuous feeding of glucose to a total amount of 180 g per liter gave 95 to 100% yields of 2-ketogluconic acid in 24 hr; feeding glucose to a total amount of 240 g per liter gave 85 to 90% yields in 32 to 40 hr.

Carbohydrate Metabolism↗

PubMed1963

NEW BACTERIAL POLYSACCHARIDE FROM ARTHROBACTER.

A bacterial strain (NRRL B-1973) isolated from soil at Guatemala City and tentatively identified as an Arthrobacter species produced a polysaccharide with unusual properties. Conditions were studied for the production of this microbial gum in shaken flasks and 20-liter fermentors. Suitable nutrients for optimal polysaccharide production included 3% glucose, 0.3% enzyme-hydrolyzed casein, magnesium sulfate, manganese sulfate, and potassium phosphate buffer (pH 7.0). Polysaccharide yields ranged from 40 to 45%, based on initial dextrose in the medium in 3- or 4-day fermentations. The gum was readily recovered from culture fluid by alcohol precipitation in the presence of an electrolyte. The Arthrobacter gum exhibited characteristics unique for a polyelectrolyte. Viscosity of solutions was not decreased by heating in the presence of salt, and the gum withstood a temperature of 121 C for 30 min. At polysaccharide levels above 0.75%, gels were formed when solutions were autoclaved with KCl. There was no significant change in viscosity over a pH range of 5.0 to 10.0.

Arthrobacter↗

PubMed1962

Production of a new polysaccharide with Cryptococcus laurentii var. flavescens.

Conditions were investigated for the production of a new gum by the yeast Cryptococcus laurentii var. flavescens NRRL Y-1401 in shaken flasks and 20-liter fermentors. The most suitable medium contained 6% commercial glucose, 0.25% autolyzed brewer's yeast, and 0.001% MnSO(4) and had an initial pH of 6.5. Polysaccharide yields, as measured by the dry weight of the alcohol precipitates, were in the range of 30 to 35% based on initial glucose.

Cryptococcus↗

PubMed1962