ANTIOXIDANT CAPACITY OF WOOD-DESTROYING FUNGI EXTRACTS

Abstract

This research study aimed to evaluate the antioxidant activity of wood destroying fungi extracts. The 13 wood destroying fungi (NK0001, NK0049, NK0182, NK0317, NW1820, NW1821, NW1826, NW1836, NW1838, NW1842, NW1847, NW1850, and NW1851) obtained from the Center of Excellence in Microbial Diversity and Suitable Utilization, Chiang Mai University, Chiang Mai. All fungal isolates were cultured on Potato Dextrose Broth (PDB) for 14 days, then the mycelium was filtered and dried in hot air oven (45 °C). Dry mycelium was separately extracted by maceration with ethanol for 48 hours, filtered and adjusted to 10 mL with ethanol. The antioxidant properties of extracts based on 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging capacity assay were analyzed. The result found that the wood destroying fungi extract (1000 ug/ml) could inhibit free radical among 5.47-90.06 %.The effective strains that indicated as high antioxidant activity (percent inhibition >50) were NW1851 (90.06%), NK001 (78.86%), NW1836 (69.12%), NW1842 (67.48%), NW1826 (62.81%), and NW1820 (59.68%). The highest antioxidant activity of the six isolates was NW1851 (IC₅₀ value = 39.96 µg/ml). Furthermore, Total phenolic, total flavonoid and total tannin contents were also determined. The highest total phenolic and total tannin contents were found in the extract of NW1851 (2.17 mg GAE/g extract and 1.34 mg TAE/g extract, respectively). Whereas, the extract of NK0049 exhibited the highest content of flavonoid (1.20 mg QE/g extract). This research indicates that wood-destroying fungi have antioxidant activity that could be used to develop products in the food, pharmaceutical, and cosmetic industries in the future.