Proteinase Biosynthesis by Streptococcus Liquefaciens: Ii. Purine, Pyrimidine, and Vitamin Requirements

Abstract

Proteinase biosynthesis by Streptococcus liquefaciens, strain 31, may be obtained from an entirely synthetic medium. Adenine and uracil seem to satisfy best the purine and pyrimidine requirement while pyridoxal and riboflavin is the combination of vitamins that leads to maximal enzyme biosynthesis. Biotin and folic acid together, or thiamine, have an inhibitory effect on enzyme synthesis. The amino acid requirements for optimum activity are unaffected by the reduced number of vitamins and nitrogen bases present in the final medium as compared to the initial medium. A reduction in the number of vitamins (to pyridoxal and riboflavin), however, showed that only adenine and uracil gave the best response to the purine and pyrimidine demands for biosynthesis; prior to this, in the presence of a complete vitamin pool, several combinations of nitrogen bases yielded equal enzymatic activity. When proteinase synthesis is plotted against time, enzyme formation ceases at about 3 hours. The shape of the curve indicates a straight-line relationship after an initial lag period of 90 minutes.

PROPERTIES OF PROTEINASE FROMSTREPTOCOCCUS FAECALISVAR.LIQUEFACIENS

“…Group D streptococci also produce an extracellular proteinase. The enzyme was partially purified by Grutter and Zimmerman (1955), the metabolic optima for enzyme biosynthesis were determined (Rabin and Zimmerman, 1956;Hartman, Zimmerman, and Rabin, 1957), and biosynthetic control mechanisms were studied (Hartman and Zimmerman, 1960). The present communication details initial chemical studies of the enzyme, and presents data that indicate basic dissimilarities with the group A proteinase.…”

Production of Hemolysin and Bacteriolysin in a Synthetic Medium by Streptococcus faecalis var. zymogenes

“…Previous experience in our laboratory had shown that it was possible for S. faecalis var. liquefaciens strain 31 to biosynthesize an extracellular protease when it was grown on a synthetic medium (15,19). A less expensive, yet excellent, medium for preliminary nutritional experiments substitutes Sheffield's N-Z Case (2) for amino acids as a source of nitrogen.…”

“…This situation is analogous to that of extracellular protease biosynthesis by S. faecalis var. liquefaciens (15,19) where the enzyme is elicited in a completely synthetic medium. Also, as with the extracellular protease (5,13,14), the concentration of arginine appears to play a singular role (see media 2 and 3, Table 2).…”

“…Synthetic media are available for the growth of hemolytic enterococci (22), but no reports are extant with regard to their utilization for lysin biosynthesis. This is to be contrasted with biosynthesis of enterococcal extracellular protease, which has been shown to be elaborated in a completely synthetic medium (15,19). It was of interest to us, therefore, to determine if a synthetic medium could be developed for lysin production and to compare these nutritional requirements with those of protease production.…”

Microbial Nutrition

“…In studies on proteinase biosynthesis in Streptococcus liquifaciens, Hart man et al (90) found that supplementing the synthetic growth medium with adenine, uracil, pyridoxal, and riboflavin resulted in maximal pro teinase synthesis. The addition of biotin, folic acid, or thiamine decreased proteinase synthesis.…”