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Effect of varying
temperature on growth, morphology and soluble protein
content of div IV and div V mutant strains of Bacillus
subtilis
Ambreen Ahmed*, Anjum Nasim Sabri and Shahida Hasnain
Department of Botany, University of the Punjab, Quaid-e-Azam
Campus, Lahore 54590, Pakistan.
*Corresponding author. E-mail:
ambreenahmed1@hotmail.com. Phone: 92-42-9231238; Fax:
92-42-9230481.
Accepted 24 July, 2007 |
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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 div-mutants
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
div-mutants 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.
Key words:
Bacillus subtilis, div-genes, div-mutants. |
