Stimulatory effects of peptides on growth of the free-living nematode Caenorhabditis briggsae.
Evidence is presented that peptide products of hydrolysis of casein, including some di- and tripeptides, but not the  constituent amino acids, can stimulate growth of C. briggsae in defined basal medium supplemented with cytochrome C and B-sitosterol.  Peptide activity may raise from amino acid imbalances in the medium which causes competitive inhibition of uptake of essential amino acids.  Such activity precludes facilitation of heme transport as the sole function of growth factor in C. briggsae.  This is the first report in a nutritional role of peptides in invertebrate metazoa.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002364:Caseins / Q000494:pharmacology; D003470:Culture Media; D003574:Cytochrome c Group; D006418:Heme; D006868:Hydrolysis; D009348:Nematoda / Q000187:drug effects / Q000254:growth & development*; D010455:Peptides / Q000494:pharmacology*; D012855:Sitosterols; D013025:Glycine max; D013268:Stimulation, Chemical
D000596:Amino Acids; D002364:Caseins; D003470:Culture Media; D003574:Cytochrome c Group; D010455:Peptides; D012855:Sitosterols; D006418:Heme