Acid-Soluble Nucleotides in an Asporogenous Mutant of Bacillus subtilis

Abstract

An asporogenous mutant of Bacillus subtilis Sp − H12-3, which is considered to have a block at stage 0, showed general growth characteristics similar to those of sporulating cultures. However, a sudden increase in the total amount of acid-soluble nucleotides observed at t 2 in sporulating bacteria was completely absent in this mutant. In sporulating cells, a marked increase in two nucleotides which were identified to be uridine diphosphate (UDP)-galactose and UDP- N -acetylglucosamine was noted, whereas UDP-glucose appeared to be accumulated in the mutant cells at t 2 . No unusual nucleotides were found in the strains of B. subtilis examined. The possible role of these UDP derivatives in early stages of sporulation in B. subtilis is discussed.

Binding of Radioactive Benzylpenicillin to Asporogenous Mutants of Bacillus subtilis During Postexponential Growth

“…Alternatively, sporulating cells of B. subtilis, B. megaterium, and B. cereus exhibit two intervals of enhanced specific binding capacity during their postlogarithmic phase of growth (21). The reproducible fluctuations in a specific binding activity of sporulating cultures as contrasted with the constant binding activity of a nonsporulating organism during postlogarithmic growth agrees with other observations which conclude that functional PG biosynthesis is required during two distinct phases of sporulation (5,11,13,23,(31)(32)(33)(34).…”

“…Symbols: 0, growth; A, penicillin binding. 5, mutant SpoIlT 94U forms nonrefractile forespores during the interval where the second peak was observed. Mutant SpoIl 7Z exhibits only the first period of enhanced specific binding capacity which corresponds to that of the wild-type organism produced 9.5 h after inoculation (Fig.…”

A mathematical model for examining growth and sporulation processes of Bacillus subtilis

“…43 The constant K P s N 2 was estimated as 1.0 X lo-' mmoll cm3 from a normal intracellular concentration of 0.25 mM. 44 IMP is located at the branch point leading to AMP and GMP in the purine-nucleotide-synthesizing pathway. IMP is synthesized through 10 consecutive reactions from PRPP and amino acid (de novo pathway).…”

Inactivation of Aspartic Transcarbamylase in Sporulating Bacillus subtilis : Demonstration of a Requirement for Metabolic Energy

“…Synthesis of new nucleic acid during sporulation appears to proceed at the expense of tumover of preexisting nucleic acids (5). Since pools of nucleotides are depleted at the end of exponential growth (2) and the growth of the cells is slow, it is unlikely that feedback inhibition or repression of enzyme synthesis accounts for this cessation of nucleotide synthesis. Mature endospores have been shown to be incapable of de novo nucleotide synthesis until after a period of protein synthesis has occurred upon germination (24).…”