Bacillus is known to form a giant colony of various
morphological patterns reflecting growth conditions,
such as nutrient concentrations and agar solidity.
When
Bacillus circulans (
B. circulans) was cultured
on an agar medium, its colony showed isotropic and
anisotropic fractal growth on flat and slant media,
respectively. Quantitative analysis by the box-counting
method showed a medium-thickness dependent
fractal similarity in the anisotropic pattern. These
various morphological patterns of the
B. circulans
colony seem to be correlated to the nutrient
abundance per area. This shows that the slant agar
culture is useful for the study of the correlation
between bacterial growth, especially multicellular
behaviors of bacteria, and nutrient abundance.
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