Growth and physiological characteristics of Bacillus subtilis L-forms.
The specific growth rate of stable Bacillus subtilis L-forms was slower (mu = 0.127) than the cell-walled form (mu = 0.219) when measured by optical density (O.D.). However, the L-form growth rate increased (mu = 0.288) when determined by viable cell counts. L-forms of B. subtilis appear to enter a phase of rapid cell division, followed by a period of cell enlargement which is associated with an increase in the number of cells with vacuoles and granules. Thus, maximum viable L-form numbers and DNA content were attained at approx. 30h, before maximum protein content was achieved (46h) and before maximum O.D. was observed at 71 h. Measurements showed that L-form cell size increased even after cell division had stopped. O.D. was therefore inaccurate for assessment of L-form growth. L-forms were sensitive to osmotic shock and unlike the cell-walled organisms from which they were derived, were resistant to penicillin, indicating a loss of peptidoglycan. The L-forms were similar to cell-walled forms in that antibiotic(s) and proteases were produced.
Allan
E J
EJ
Department of Agriculture, University of Aberdeen, UK.
Amijee
F
F
Tyson
R H
RH
Strang
J A
JA
Innes
C M
CM
Paton
A M
AM
D000900:Anti-Bacterial Agents / Q000096:biosynthesis; D001412:Bacillus subtilis / Q000254:growth & development* / Q000502:physiology / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000032:analysis; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D007700:Kinetics; D007740:L Forms / Q000254:growth & development* / Q000502:physiology; D009113:Muramidase / Q000494:pharmacology; D010406:Penicillins / Q000494:pharmacology; D014617:Vacuoles / Q000648:ultrastructure; D014867:Water / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D010406:Penicillins; D014867:Water; D009113:Muramidase