Glucose 1 phosphate as a selective substrate for enumeration of Bacteroides species in the rumen

Abstract

When glucose 1 phosphate was used as the only added energy source in a selective roll tube medium, colony counts for rumen contents ranged from 17.8 to 84.8% of the total culturable count. Percentages were highest in rumen contents from sheep fed high concentrate rations. From a total of 73 cultures isolated from glucose 1 phosphate roll tubes, only 15.1% were presumptively identified as Bacteroides species. Strains presumptively identified as Butyrivibrio, Selenomonas, Treponema, Streptococcus bovis, and Lachnospira also fermented glucose 1 phosphate. Thus, glucose 1 phosphate would not be useful as a selective substrate for isolation or enumeration of Bacteroides species from the rumen.