Successful Rescue of Wild Strains Using Sawdust and Rice Husk-based Substrate.

<b>Background and Objective:</b> <i>Trametes versicolor</i> has not only been valued in medical use but also in environmental protection. One of the major challenges currently faced in the commercial cultivation of <i>T. versicolor</i> is finding superior strains that can produce high yields. In an attempt to search for high-yield potential <i>T. versicolor</i>, two wild strains, namely VNUA and BV, were isolated and evaluated for potential cultivation. <b>Materials and Methods:</b> Optimized culture conditions were set up by one-individual factor-at-a-time. Four different kinds of culture media, including Czapek, Raper, PGA and modified Potato Dextrose Agar (PDA), were investigated to ascertain the optimal media. The efficiency of sawdust and rice grain for mother spawn production was evaluated. Different combinations of sawdust and rice husk were tested to investigate the most favorable substrate mixtures. <b>Results:</b> The ideal medium and temperature for the favorable mycelial growth of <i>T. versicolor</i> were PGA and 30°C, respectively. The optimal spawning material for upscaling of the mycelium was Treatment D (20% rice grain, 79% sawdust and 1% calcium carbonate). The strains were successfully cultivated in a basal substrate combination of sawdust and rice husk supplemented with wheat bran. Investigated strains responded differently to different substrates cultivation. Of note, compared with strain BV, strain VNUA showed a significantly higher biological efficiency (7.3%). <b>Conclusion:</b> Wild <i>T. versicolor</i> strains were successfully fructified under artificial cultivation conditions. Strain VNUA can be considered as a potential strain for commercial cultivation. The use of sawdust for the spawn production of <i>T. versicolor</i> can reduce the cost of manufacturing.