Effect of varying temperature on growth, morphology and soluble protein content of div IV and div V mutant strains of Bacillus subtilis

  • A Ahmed
  • AN Sabri
  • S Hasnain
Keywords: Bacillus subtilis, div-genes, div-mutants


Cell division affecting genes (div genes) have been mapped on circular chromosome of Bacillus subtilis. In the present work, div-gene(s) involved in mini-cell production and temperature sensitive cell
division were studied. Effect of different temperatures (25, 37 and 42°C) and varying incubation periods (4, 16, 24, 48, 72 and 96 h) on the colony and cell morphology, staining behavior, growth rate and
soluble protein content of PY79 (wild type) and div mutant strains (IA197, IA292, IA314, IA315) was studied. PY79 differs from div-mutants in colony morphology especially in colony margin. High
temperature severely affects cell morphology (cell size, cell types, formation of filaments/minicells and staining behavior of cells). Degeneration and lysis was more in div mutant strains when compared with PY79 especially at 42°C. Sporulation was found to be affected at non-permissive temperature and divmutants form defective spores at 25 and 42°C. At 37°C spores were formed by div-mutants but were
defective. Also spores produced at 42°C by div-mutants were defective in spore germination. All divmutants have less protein content when compared with PY79 at all temperatures. Also protein content
decreases at sporulation stages. Hence div-mutations are multifaceted mutations which cause effects on cell morphology, sporulation and germination processes in B. subtilis.

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eISSN: 1684-5315