Fractal analysis of subsurface growth of a genetically modified strain of Gliocladium virens and its parental strain

The structure of a fungal colony growing on an agar surface has been shown to follow a fractal model. This report investigates the fractal dimensions of subsurface colonies of a transformed strain of Gliocladium virens (GvT6) and the unaltered strain (Gv29-8). Strain GvT6 contains the opd gene from Flavobacterium sp. Fractal analysis of GvT6 and Gv29-8 should indicate changes in the branching character of a fungus due to genetic modification. A system was developed to capture microscopic images of a growing fungal colony in the subsurface of ground lignite. Images were taken at two-day intervals over a six-day period. A combination of image processing algorithms gave binary images of each fungal colony at each sampling time. The fractal dimensions of the colonies were determined from analysis of these images. Our research showed the fractal dimensions of colonies of GvT6 and Gv29-8 were indistinguishable, which indicated the two strains displayed similar branching characteristics. The fractal dimensions of both strains changed from 1.334 to 1.854 as the colonies matured, indicating more homogeneous coverage within the area colonized. Other researchers have found similar fractal dimensions for other fungal species. The radial extension rate of GvT6 was less than that of Gv29-8, which indicated strain GvT6 colonized the subsurface matrix at a slower rate than Gv29-8, even though the branching pattern was similar.

Fractal analysis of subsurface growth of a genetically modified strain of Gliocladium virens and its parental strain Academic Article