A Microorganism Exhibiting a Growth Requirement for Peptides

Abstract

A strain of bacteria designated SF and tentatively classified as Al-caligenes sp. grows rapidly when L-leucylglycine is sole source of N, but does not grow when only leucine and glycine, or glycine alone is N source; L-leucine promoted growth only slightly. Glycyl-L-leucine and acetyl-L-leucine showed little growth promoting power, while L-leucylglycylgiycine produced a good growth response. That the organism does not need dipeptide per se is indicated by growth with only L-valine which stimulates more effectively than L-leucylglycine. Glycine acts as growth inhibitor.