GLYCOGEN OF ENTERIC BACTERIA

Abstract

The presence of glycogen in bacteria can be detected by absorption bands characteristic of glycogen in the bacterial infrared spectrum. Semiquantitative analysis can be accomplished using a standard curve which relates glycogen concn. to the ratio of absorbance at 9.75[mu] (glycogen band) to absorbance at 6.5[mu] (protein band used as an internal standard). It was found that glycogen concns. show marked strain variation and are influenced by the content of the medium, age of culture, temp. of incubation, and density of inoculum. Utilizable carbohydrates in the medium usually increase glycogen levels, particularly when incubation is done at low temps. (15[degree]-20[degree]C). Glycogen levels as high as 48% of dry wt. were found. The glycogens of Aerobacter aerogenes, Escherichia coli, and Salmonella montevideo were isolated and studied. Glycogen in the pure state and in crude bacterial lysates was found by ultracentrifugal analysis to be poly-disperse and of very large particle size.