Antibacterial Activity of Spent Substrate of Mushroom

Abstract

Nowadays, the uncontrolled use of antibiotics has created the problem of bacterial resistance to them, what has motivated the search for new alternatives of drug for the treatment of bacterial diseases. Here, we compare antimicrobial activity of spent substrate of mushroom Pleurotus ostreatus combined or not with medicinal plants and Lentinula edodes, against Escherichia coli, Staphylococcus epidermidis, Bacillus subtilis, Salmonella tiphymorium, Staphylococcus aureus and Micrococcus luteus. We designed three mixtures, barley straw to be used as a substrate of cultivation of mushroom Pleurotus ostreatus and oats or cedar for the cultivation of mushroom Lentinula edodes and five mixtures with herbs (barley straw/Chenopodium ambrosioides L., barley straw/Mentha piperita L., barley straw/Rosmarinus officinalis L., barley straw/Litsea glaucescens Kunth and barley straw/Tagetes lucid Cav) to be used as a substrate of cultivation of mushroom Pleurotus ostreatus; were obtained aqueous extracts from all spent substrates; extracts were tested for antibacterial activity. The protocol was a completely randomized assay with a factorial arrangement design. The data were analyzed with PROC GLM, SAS. The results showed that in the case of Escherichia coli the greatest inhibition zone was of 12.66 mm at a concentration of 6 mg mL-1, with treatment of Lentinula edodes/cedar; Salmonella tiphymorium showed a greatest inhibition zone of 31.10 mm to a concentration of 5.12 mg mL-1, with treatment of Pleurotus ostreatus/barley straw; Staphylococcus aureus showed a greatest inhibition zone of 9.33 mm to a concentration of 100 mg mL-1, with the treatment of Lentinula edodes/cedar; Micrococcus luteus showed a greatest inhibition zone of 15.00 mm to a concentration of 50 mg mL-1, with the treatment Lentinula edodes/oats and finaly, Staphylococcus epidermidis showed a greatest inhibition zone of 33.33 mm at a concentration of 50 mg mL-1, and 40.00 mm at a concentration of 50 mg mL-1, with treatment the spent substrate from Pleurotus ostreatus that contained barley straw and the mix barley straw/Mentha piperita L, respectively. In conclusion, the results suggest that it is possible to use indistinctly the spent substrate of Pleurotus ostreatus and Lentinula edodes, as well as the mix barley straw/Mentha piperita L as source of extracts with antibacterial activity.