Evaluation of antibacterial activity of mangosteen (Garcinia mangostana L.) pericarp extract against rice leaf blight bacteria (Xanthomonas oryzae pv. oryzae) at various temperatures and durations of fruit storage

Abstract

Bioactive contents of mangosteen pericarp can be used as antibacterial agent. This study aimed to examine the antibacterial activity of mangosteen pericarp extract (Garcinia mangostana L.) against rice leaf blight bacteria (Xanthomonas oryzae pv. oryzae) at different temperature and duration of fruit storage, and to identify the antibacterial bioactive metabolites present in the pericarp extract. The antibacterial experiment was arranged with Randomized Completely Block Design (RCBD) with two factors, namely: storage temperature (0, 13.5, and 27 °C) and storage duration (1, 7, and 14 days), with 3 replicates. There was significant interaction between storage temperature and storage duration towards the antibacterial activity of mangosteen pericarp extract. The best was showed by the fruits that was kept in temperature of 13,5 °C for 7 days of storage with inhibition zone of 24.46 mm and the minimum inhibitory concentration (MIC) of 25%. Gas chromatography-mass spectrometry (GC-MS) result showed antibacterial bioactive compounds including (-)-Alpha-Copaene and 2H,6H-Pyran [3,2-B] Xanthen-6-One,5,8-Dihydroxy-9-Methoxy-2,2-Dimethyl-10-(3-Methyl-2-Butenyl)-on the fruits stored in temperature of 0 °C and duration of 1 day, and Copaene on the fruits stored during 7 days on temperature of 13,5 °C. In conclusion, mangosteen pericarp is a promising source of antibacterial bioactive against Xoo pathogen.