Evaluating Laccase Enzyme Activity and Decolorization Ratio for Early Detection of Strain Degeneration in Lentinula edodes

Abstract

Shiitake mushroom (Lentinula edodes) is a highly sought after edible mushroom due to its nutritional and medicinal properties, however, due to repeated cultivation shiitake often experience strain degeneration, which leads to a decline in fruiting body production, reduced yields, and economic losses for cultivators. Furthermore, because degenerate mycelia appear visually similar to healthy mycelia, making early detection difficult. Recent studies suggest that laccase, a key enzyme in mushroom development, could serve as a potential biomarker for strain degeneration. This study aims to evaluate two potential methods for the early detection of strain degeneration in L. edodes measuring laccase enzyme activity using the 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) or ABTS assay. To complement the laccase activity assay, a decolorization assay was done to assess the fungi's ability to decolorize bromothymol blue (BTB). The result shows that the degenerate strain exhibits lower laccase activity starting from day 3 until day 5 and the disparity is inoticeable past day 6. The degenerate strain also shows lower decolorization ability, which becomes apparent starting from the second day and continues throughout the cultivation period until day 5, where the decolorization becomes stagnant for both degenerate and non-degenerate strains. These findings could offer a simple and efficient method for identifying degenerate strains early in the cultivation process, mitigating potential economic losses, and ensuring the production of high-quality shiitake mushrooms.