PRODUCTION AND CHARACTERIZATION OF BRUCELLA SPHEROPLASTS.

Hines, William D. (University of Chicago, Chicago, Ill.), Bob A. Freeman, and Gary R. Pearson. Production and characterization of Brucella spheroplasts. J. Bacteriol. 87:438-445. 1964.-Spheroplasts of Brucella were induced by glycine, penicillin, and a combination of the two. These spheroplasts lacked cell-wall endotoxin but did react with antiserum prepared against cell wall and against whole cells. Phase-contrast photomicrographs and electron micrographs are presented, which show no morphological difference between the protoplasts produced by penicillin and by glycine. The glycine and glycine-penicillin spheroplasts were osmotically sensitive, would not reproduce, and only a small percentage reverted to the bacillary form. Penicillin spheroplasts would not reproduce and were not osmotically sensitive. Penicillin spheroplasts showed significant reversion when induced by low concentrations of penicillin, but the rate of reversion decreased with increasing antibiotic concentration. Penicillin and glycine spheroplasts adsorbed brucellaphage at a reduced rate compared with normal Brucella, but spheroplasts produced by the combined action of penicillin and glycine failed to demonstrate brucellaphage adsorption.