1. Horváth, I., Gadó, I., and Szentirmai, A., J. Bact., 78, 293 (1959).
2. Horváth, I., Gadó, I., and Szentirmai, A., Acta Microbiol. Hung. (in the press).
3. Adalberg, E. A., Amino Acid Metabolism, 419, edit. Mc Elroy and Glass (Johns Hopkins Press, Baltimore, Maryland, 1955).
4. Strassman, M., and Weinhouse, S., ibid., 452.
5. Umbarger, H. E., ibid., 442.