Abstracts » Biological sciences

Some growth and metabolic characteristics of monensin-sensitive and monensin-resistant strains of Prevotella (Bacteroides) ruminicola

Article Abstract:

The effects of monensin on two monensin-sensitive and two monensin-resistant strains of Prevotella ruminicola were examined to evaluate the possible effects of monensin in ruminants. Monensin resistance did not confer a univeral resistance to other ionophores. Logarithmic cultures of monensin-sensitive strains were not inhibited by the same concentration of monensin as freshly inoculated cultures. The rate of glucose utilization as well as protein yields decreased in both types of strains upon monensin challenge. Except for one resistant strain, challenge with monensin raised succinate production at the expense of acetate and propionate.

Bacteriology, Rumen, Rumen microbiology, Rumen fermentation, Monensin

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Glycogen formation by the ruminal bacterium Prevotella ruminicola

Article Abstract:

The ratio of glycogen to protein in the ruminal bacteria Prevotella ruminicola was found to be relatively low during exponential growth. However, when cell growth slowed during the transition to the stationary phase, the ratio increased. Glycogen accumulation in glucose-grown cells was threefold lower than that in maltose-grown cells. In continuous cultures provided with maltose, much less glycogen was synthesized at high than at low dilution rates, where maltose was limiting. These findings show that glycogen synthesis was stimulated at low growth rates and was also affected by the growth substrate.

Bacteria, Glycogen

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Role of phosphorolytic cleavage in cellobiose and cellodextrin metabolism by the ruminal bacterium Prevotella ruminicola

Article Abstract:

The phosphorolytic cleavage of cellobiose and cellodextrin is studied to determine its role in the bacterial metabolism by the ruminal bacterium Prevotella ruminicola. Results show that phosphorolytic cleavage of cellobiose and cellodextrin leads to the formation of phosphorylated glucosyl molecules without the investment of ATP. The data also suggest that cellobiose hydrolytic cleavage activity is threefold greater than phosphorolytic cleavage activity.

Microbial metabolism, Scission (Chemistry)

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