title: Growth and physiological characteristics of Bacillus subtilis L-forms.
abstract: 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.
authors: Department of Agriculture, University of Aberdeen, UK.
authors: E J
authors: EJ
authors: Allan
authors: F
authors: F
authors: Amijee
authors: R H
authors: RH
authors: Tyson
authors: J A
authors: JA
authors: Strang
authors: C M
authors: CM
authors: Innes
authors: A M
authors: AM
authors: Paton
mesh_terms: 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
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D010406:Penicillins; D014867:Water; D009113:Muramidase