Ravi Karisvini, Tan Yee Shin, Kamali Mohd Zahurin Mohamed, Muniandy Sithi Vinayakam
Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Mushroom Research Centre, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Curr Microbiol. 2025 Apr 3;82(5):229. doi: 10.1007/s00284-025-04207-z.
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 and area fractal dimension D. 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).
灵芝种类是一种主要的木材腐朽真菌，因其营养价值而随处可见。面临的挑战包括将菌丝体生长形态分析的二维成像与分形形态联系起来，以及确定最佳营养成分以在蘑菇产业中大规模提高产量。在本研究中，使用琼脂平板法对灵芝和新日本灵芝在不同营养物质（包括马铃薯葡萄糖琼脂（PDA）、半强度PDA和琼脂糖）上的生长动态进行了比较研究。利用宏观图像确定平均生长前沿长度、各向同性、面积和周长分形维数以及异速生长比例指数。结果表明，与其他培养基相比，灵芝菌丝体在PDA上的生长速度最快（第5天为10.51±0.018厘米）。葡萄糖（碳源）是菌丝体生长所必需的。同时，新日本灵芝菌丝体在PDA和半强度PDA上的生长速度相似。新日本灵芝更具侵略性，即使在低营养浓度的培养基上也能生长。采用盒计数法计算周长分形维数D和面积分形维数D。分支较弱的菌丝体分形维数更接近1.0（稀疏线状），而密集分支的分形维数更接近2.0（面积填充）。异速生长比例指数（σ）定义为周长分形维数与面积分形维数之比，用于描述菌丝体形态。因此，分形和图像分析对于研究菌丝体网络中不断演变的复杂模式至关重要。该研究的意义有助于大规模蘑菇产业，符合可持续发展目标2（SDG2）。
