Asporogenous mutants ofBacillus subtilis marburg

Extracellular enzyme synthesis in the genus Bacillus.

“…Early studies of protease synthesis during the batch culture growth cycle established a relationship between the maximal rate of protease synthesis and the initiation of sporulation (13,185). Furthermore, the analysis of Spomutants revealed that many of these strains did not produce extracellular protease and that reversion to sporogeny was accompanied by the ability to synthesize protease (279). The early studies were ambiguous, however, because they failed to distinguish the different proteases that were being secreted by the bacilli.…”

“…Dancer and Mandelstam (59) observed that thymine starvation, which prevents sporulation in B. subtilis, also prevented the synthesis of neutral protease, whereas it had no effect on the synthesis of a-amylase, an exoenzyme for VOL. 41, 1977 on July 6, 2020 by guest http://mmbr.asm.org/ Downloaded from which Amy-Spo+ mutants of B. subtilis have been described (279). On this basis they categorized the neutral protease as an enzyme not primarily involved in sporulation but whose synthesis is dependent on the sequence of events leading to the formation of the endospore (ii, above) and a-amylase as an enzyme completely divorced from sporulation but synthesized in response to the change in cultural conditions associated with the end of exponential growth.…”

A Bacitracin-negative Mutant of Bacillus licheniformis Which is Able to Sporulate

“…Mutants have been isolated which show no antibiotic activity which also produce no spores (Schaeffer, 1967;Schmitt & Freese, 1968). Mutants unable to sporulate normally can be blocked at different stages in the sporulation process (Young & Fitz-James, 1959).…”

“…Mutants which are both antibiotic and sporulation negative are blocked at an early stage, whereas mutants blocked at later stages are found to be non-sporulating antibiotic producers and restoration of antibiotic production by reversion, transduction or transformation restores the ability to sporulate (Hoch & Spizizen, 1969;Schaeffer, 1969). Schmitt & Freese (1968) and Schaeffer (1967) conclude that the production of peptide antibiotics is essential for sporulation to reach stage one. Schaeffer (1969) isolated five partially antibiotic deficient mutants of Bacillus subtilis which are capable of forming spores and suggests that one non-essential antibiotic out of several produced has been lost in these mutants.…”

Physiological Studies on Early‐blocked Sporulation Mutants of Bacillus subtilis

“…This hypothesis was tested by comparing amylase activity in the medium of both wild and mutant cultures (amylase is produced after to with the same kinetics as the other exoenzymes (May & Elliott, 1968) but this production is unrelated to sporulation (Schaeffer, 1968). Amylase and M-proteinase activity were found to be reduced to the same extent (30%) when strain ~p -0~…”