Extracellular manganese-stimulated deoxyribonuclease as a marker event in sporulation of Bacillus subtilis

Abstract

A considerable amount of Mn2+-stimulated DNAase (deoxyribonuclease) activity is released by Bacillus subtilis 168 during sporulation in a glucose-deficient medium; much smaller amounts are released during starvation for phosphate or nitrogen. Protein synthesis is required. Two forms of evidence are presented that production of the DNAase is associated with events late in stage II of sporulation. 19 Thymidine starvation, which inhibits the biochemical events associated with sporulation, also inhibits release of the DNAase. 2. Several asporogenous mutants blocked at stage II or earlier and unable to produce alkaline phosphatase (a stage-II event) do not produce the enzyme. Mutants blocked towards the end of stage II or later produce both enzymes. During sporulation of the wild-type strain, the DNAase appears about 1 h after alkaline phosphatase. The results suggest that production of the DNAase is controlled by a still-undiscovered stage-II genetic locus.

Variety of Sporulation Phenotypes Resulting from Mutations in a Single Regulatory Locus, spoIIA, in Bacillus subtilis

“…Previous investigations (Waites et al, 1970;Piggot, 1973;Akrigg & Mandelstam, 1978) showed that spollA mutants do not produce alkaline phosphatase (Pho-phenotype) or DNAase (Nuc-phenotype) during sporulation. However, preliminary screening of the 12 possible spollA mutants using DNAase detection agar showed that five of them produced DNAase (Nuc+) whereas the remainder did not (Nuc-).…”

“…These Nut+ mutants, 560,561 , 562,563 and 564, and one of the Nuc-strains, 565, were then tested quantitatively for DNAase production during sporulation. Alkaline phosphatase was also measured since production of this enzyme is usually correlated with production of DNAase in sporulation mutants (Akrigg & Mandelstam, 1978).…”

“…Earlier work had shown that mutations in this locus result not only in asporogeny or oligosporogeny but also in failure to produce alkaline phosphatase (Coote, 1972a;Piggot, 1973). It was subsequently shown that there is also a failure to produce extracellular DNAase (Akrigg & Mandelstam, 1978). None of the later sporulation events, e.g.…”

“…Mutants blocked early in stage I1 produce neither of the enzymes; those blocked later produce both (Waites et al, 1970;Piggot & Coote, 1976;Akrigg & Mandelstam, 1978;Young & Mandelstam, 1979). It is not known whether they play a direct role in sporulation or whether they belong to a category of secondary events (Coote & Mandelstam, 1973).…”

Establishment of cell‐specific transcription during sporulation in Bacillus subtilis

“…Second, sporulation-associated enzymes alkaline phosphatase and DNAase are both found mainly or exclusively in the extracellular medium (Glenn and Mandelstam, 1971;Akrigg and Mandelstam, 1978). It is difficult to imagine how such enzymes could reach the culture medium if expressed in the prespore, since, at least after prespore engulfment, the protein would have to traverse three lipid bilayers of differing polarity.…”