title: Twist state phenotypes of Bacillus subtilis macrofibre mutants.
abstract: The range of macrofibre twist states that can be achieved by various strains of Bacillus subtilis has been examined as a function of two variables: growth temperature and medium composition. Two graphic techniques were utilized to organize and compare data which pertain to the complex phenotypes of macrofibre mutants. The steady state twist states of strains were determined by qualitative examination. Structures were produced at each of the extremes of temperature and medium composition. Patterns obtained from a graphical representation of these data permitted the strains to be grouped into three classes: (A) strains in which helix-hand inversion could be triggered by nutrition at both 20 degrees or 48 degrees C, and by temperature in either medium; (B) strains in which a more limited set of conditions could induce inversion, and (C) strains which were restricted to either the right- or left-hand domain of twist states. Genetic factors governing these patterns were examined. Quantitative measurements of static twist were obtained over the entire temperature and media range, providing a detailed picture of the dependence of twist upon these environmental influences. Although the macrofibre twist state phenotype (as a function of both variables over the entire range of conditions) of each strain was unique, common features were discernible in all strains. Although some strains were limited to a single helix hand under all conditions studied, none were found to be restricted to a single twist state.
mesh_terms: D001412:Bacillus subtilis / Q000166:cytology* / Q000235:genetics; D003470:Culture Media; D009154:Mutation; D010641:Phenotype; D013696:Temperature
chemical_list: D003470:Culture Media