Pleiotropic phenomena in autolytic enzyme(s) content, flagellation, and simultaneous hyperproduction of extracellular α amylase and protease in a Bacillus subtilis mutant

Abstract

A mutant of B. subtilis 6160 that had been isolated by its hyperproduction of α amylase and protease lacked flagella and motility, and its content of autolytic enzyme(s) was reduced to one third to one fourth that of the parent. These phenotypic differences were completely co transferred by the deoxyribonucleic acid (DNA) of the mutant when five DNA recipient strains of B. subtilis were transformed. The revertants, isolated by motility with a frequency of approximately 10-7, recovered a normal level of autolytic activity and showed reduced productivity of α amylase and protease. This point mutation allowed normal flagellin synthesis, spore formation, and rate of growth. The comparison of cell envelope of the mutant with that of the parent indicated that there was no significant difference except loss of flagella. Therefore the association at the cell surface of a group of extracellular proteins consisting at least of α amylase, proteases, flagellin, and autolytic enzyme(s) seem to be coordinately regulated by the gene or seem to be affected coordinately by certain undetected alterations of the cell envelope.