Effect of Streptomycin on the Assimilation of Amino Acids by Bacillus Subtilis

Abstract

Studies on the utilization of amino acids by B. subtilis during growth in the presence of streptomycin indicate that the antibiotic greatly influences the rate of amino acid uptake by the organism. There is, however, no selective action in the ultimate utilization of amino acids. The variation in the rate of assimilation of amino acids from the broth as induced by streptomycin may account for the difference in the rate of growth of bacterial cells. The antibiotic causes the accumulation of lesser number of free amino acids as compared to those accumulated in the streptomycinuntreated cells.Earlier investigations of amino acid metabolism by GALE (1) and TAYLOR (2) have shown that the Gram-positive cocci are able to assimilate certain amino acids and concentrate them in the free state in the internal environment before metabolism into protein. GALE (3), GALE et al. (4) and GALE and FOLKES (5) also studied the assimilation of amino acids in bacterial metabolism.The utilization of amino acids by Bacillus subtilis during its production of an antifungal antibiotic was studied by MAJUMDAR and BOSS (6). But no information is available on the amino acid assimilation by B. subtilis in the presence of streptomycin.It has been previously observed in course of studies on the effect of streptomycin on the metabolism and growth of B. subtilis that streptomycin greatly interferes with the glutamic acid metabolism (7). In the present work an effort has been made to study the effect of streptomycin on the assimilation of amino acids by B, subtilis. EXPERIMENTAL Fermentation experimentsFor studying the effect of streptomycin on the utilization of amino acids by B, subtilis strain B3, a producer of an antifungal antibiotic, mycobacillin * Present address :