Antibacterial and antioxidant activity of the ethyl acetate extract of two strainsof Thai Laetiporus sulphureus mushroom

Laetiporus sulphureus, a wood-decaying mushroom, has been reported to be a good source of natural bioactive components. Traditionally used in folk medicine, L. sulphureus has shown its beneficial effects on human health. This study was conducted to evaluate the antibacterial and antioxidant activities of two strains of Thai L. sulphureus mushrooms (MFLUCC 12-0546 and MFLUCC 12-0547) using disc diffusion assay and an ABTS antioxidant assay, respectively. Initially, the mushroom mycelia were prepared and cultured in potato dextrose broth (PDB) and malt extract broth (MEB) at 30°C for 10 days. The ethyl acetate extracts were prepared using the culture supernatants and used for both assays. Although the two mushroom strains were very similar in morphology, they exhibited different antibacterial and antioxidant activities. For antibacterial activity, the MEB extracts had a better effect on antibacterial activity than those obtained from the PDB culture, whereas the PDB extracts showed a better antioxidant activity than those obtained from the MEB cultivation. The results showed that the L. sulphureus extracts obtained from its mycelial state possess antibacterial and antioxidant activity. It should also be noted interestingly that both biological activities tested in the present study are dependent on the mushroom strains and media used for cultivation.