Elucidation of Foraging Strategies of Ganoderma lucidum and Ganoderma neo-japonicum on Different Nutrients Composition Using Fractal Morphology.

Abstract

Ganoderma species are major wood-decaying fungus found everywhere due to its nutritional benefits. Challenges include connecting 2D imaging of mycelium growth morphology analysis to fractal morphology and determining optimum nutrient composition to increase production yield on a larger scale in mushroom industries. In this research, a comparative study of the growth dynamics of Ganoderma lucidum and Ganoderma neo-japonicum was conducted on different nutrients including potato dextrose agar (PDA), half-strength PDA and agarose using agar plate method. Macroscopic images were used to determine average growth front length, isotropy, area and perimeter fractal dimensions, and allometric scaling exponents. The result showed that G.lucidum mycelium recorded the fastest growth rate (10.51 ± 0.018 cm on 5th day) in PDA compared to other media. Dextrose (carbon source) is necessary for mycelial growth. Meanwhile, G.neo-japonicum mycelium showed similar growth rate on PDA and half-strength PDA. G.neo-japonicum was more aggressive and could thrive even on low nutrient concentration media. Box-counting approach is used to calculate perimeter fractal dimension D_P and area fractal dimension D_A. Mycelium with weak branching has fractal dimension closer to 1.0 (sparse line-like), while dense branching has fractal dimension closer to 2.0 (area filling). The allometry scaling exponent (σ) defined as the ratio of perimeter fractal dimension to area fractal dimension is used to describe mycelium morphology. Therefore, fractal and image analysis are crucial in studying evolving complex patterns within mycelium networks. The significance of the study contributes to the large-scale mushroom industry, aligning with Sustainable Development Goal 2 (SDG2).