SCREENING OF ANTIFUNGAL ACTIVITY ON RAW RUBBER SHEET BY NATURAL EXTRACTS

Abstract

Fungal contamination on raw rubber sheets causes a low selling price. Therefore, it is very important to control the growth of these fungi. The objective of this study is to search for natural extracts that can be used to prevent fungal growth on raw rubber sheets. Six fungal isolates; P1, A1, A2, A3, A4, and A5 were found on studied raw rubber sheets. They were morphologically classified into two genera, Penicillium and Aspergillus. These isolates were tested with 7 herbal extracts; tumeric, garlic, pomelo, lime, kaffir lime, neem, and large leaf neem by agar disk diffusion method.  Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) were also determined by broth dilution method. The results showed that distilled water garlic extract was the most effective agent against the growth of the tested isolates.  Minimal inhibitory concentrations (MICs) of garlic extract for P1, A1, A2, A3, A4, and A5 were 0.31, 0.31, 0.31, 0.63, 0.63, and 0.31 g% while minimal fungicidal concentrations (MFCs) were 0.63, 0.63, 0.63, 1.25, 1.25, and 1.25 g%, respectively. The garlic extract at 10 times MIC could kill all isolates within 5 hours. In conclusion, the garlic extract is potentially effective as fungistasis and fungicide used to prevent or kill fungal contamination on raw rubber sheets.