A Study of the Nutrition of Caenorhabditis Briggsae (Rhabditidae) Fed On 14C and 32P-Labelled Bacteria

Abstract

Cultures of Caenorhabditi.r briggsae were fed on Escherichia coli pre-labelled with 14C or 32P. Budgets were constructed to show what proportions of the digested 14C or 32P were retained by the nematode, excreted and, with 14C, respired. A substantial part of the digested C and P appear as soluble metabolites in the medium. Data are also presented on the distribution of 14C and 32P in major tissue fractions of the nematode, and on the rate of loss of radioactivity from nematodes in culture. The percentage of 14C from digested E. coli retained within the nematodes' tissue varied with the substrate used to label E. coli from 17% to 51%. It is suggested that the percentage retained when feeding on E. coli labelled with [14C]NaHCO3, about 20%, in the experiments reported may be a useful criterion in studies of the ecological energetics of bacteria-feeding animals.