Inversion of helix orientation in Bacillus subtilis macrofibers

Area of Science:

• Microbiology
• Biophysics
• Cell Biology

Background:

• Bacillus subtilis macrofibers exhibit reversible helix hand changes influenced by the nutritional environment.
• Previous research established the nutritional control over macrofiber handedness.

Purpose of the Study:

• To investigate the influence of temperature and divalent ions on Bacillus subtilis macrofiber helix hand inversion.
• To identify additional factors governing macrofiber handedness beyond nutrition.

Main Methods:

• Utilizing lyt mutants and wild-type strains of Bacillus subtilis.
• Manipulating temperature and divalent ion concentrations.
• Observing helix hand transitions and correlating them with environmental factors.

Main Results:

• Both lyt mutants and wild-type strains demonstrated temperature-dependent helix hand inversion.
• The transition occurred within a narrow temperature range (approx. 2.5°C) in the low to mid-40s Celsius.
• Divalent ion concentration also significantly influenced macrofiber helix orientation.
• Macrofiber handedness is determined by a combination of genetic, thermal, nutritional, and ionic factors.

Conclusions:

• Helix hand inversion in Bacillus subtilis macrofibers is a multifactorial process.
• Cell growth is a prerequisite for helix hand inversion.
• Standard growth conditions favor the formation of right-handed structures.