Helical Growth and Macrofiber Formation of Bacillus Subtilis 168 Autolytic Enzyme Deficient Mutants

Two poorly lytic, chain-forming mutants of Bacillus subtilis 168, strains FJ3 and FJ6, each 90-95% deficient in the production of N-acetylmuramoyl-l-alanine amidase and endo-beta-N-acethyglucosaminidase, grew helically under a variety of cultural condtions. The structures formed ranged in complexity from double-standed helices to complex aggregates of entangled and interwoven single chains and multistransded helical fibres. Factors favoring this type of helical growth were investigated. Occasional tight single-standed corkscrew like forms were detected in the mutant cultrues. Two other poorly lytic mutant strains of Bacillus were also found to have helical growth capacity. These results have been interpreted as support for the recently proposed (1976) tension restricted helical growth model of Mendelson.