HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hoover, W. H. Articles by Flipse, R. J. Search for Related Content PubMed Articles by Hoover, W. H. Articles by Flipse, R. J.

Carbon Sources for in Vitro Protein Synthesis by Rumen Bacteria^{1, 2,}

Department of Dairy Science, The Pennsylvania State University, University Park

ABSTRACT

In vitro tracer studies were conducted to determine the rate at which several volatile fatty acids and glucose were utilized by rumen bacteria, and the amount of carbon from these sources incorporated into bacterial proteins, nucleic acids, and polysaccharides. The rate at which each metabolite was utilized by rumen microorganisms was estimated on the basis of the decline in specific activity during incubation. The average rates calculated for acetate, propionate, butyrate, and valerate, in milligrams/liter/hour, were 131.0, 18.2, 13.2, and 0.6, respectively. Glucose was utilized in proportion to the amount added. At 10 and 20 mg/milliliter levels, 556 and 1,155 mg/liter/hour were utilized, respectively.

After incubation, some cellular components of the microorganisms were examined for C¹⁴ content. Nucleic acids contained label from acetate and glucose, but little or no activity from propionate, butyrate, or valerate. Activity from all labeled metabolites was found in the proteins. Of the activity that disappeared from the labeled acetate, propionate, butyrate, valerate, and glucose during incubation, the average amounts incorporated into proteins were 2.5, 2.1, 1.6, 2.6, and 2.9%, respectively. Cellular polysaccharides also became labeled from each source.

¹ Authorized for publication on September 5, 1962, as Paper No. 2702 in the Journal series of the Pennsylvania Agricultural Experiment Station.

² Data presented in this paper were taken from a thesis submitted by the senior author to the Graduate School in partial fulfillment of the requirements for the Ph.D. degree.

³ Present address: Department of Animal Science, University of Maine, Orono.