Study of trace metals concentration and antimicrobial properties of tropical Aloe vera plant from southern India

Abstract

This study was carried out with an objective to investigate the antibacterial and antifungal potentials and trace metals concentrations in Aloe vera (Linn) plant leaves. Fresh leaves of Aloe vera were collected from Tiruchirappalli district of Tamil Nadu during the period of February - March 2014. The 100 g of shade dried A. vera leave power was used to collect the methanol extraction of the test plant by the soxhlet apparatus. The extracted solutions were dried by hot air oven at 60 C for 48-72 h for further analysis. The antimicrobial activity of Aloe vera methanol extract was examined with six various pathogenic microorganisms such as gram positive, gram negative and fungal strains using the disk diffusion test. The two tested concentrations such as 0.60 and 1.20 mg/disc produce zone of inhibition on muller hinton agar (MHA) and potato dextrose agar (PDA) plates for bacteria and fungi, respectively. In this study, higher (1.20 mg) concentration got greater sensitivity than lower (0.60 mg) concentration against all strains. All the microbial strains depict higher sensitivity to the higher concentration (1.2 mg / disc) for the test sample when compared to the positive control except bacterial strains such as Aeromonas liquefaciens MTCC 2645 (B1). The trace metal analyses of the plants were also carried out. The mean concentration of trace metals such as cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb) and zinc (Zn) were 0.04, BDL, 0.06, 0.08, BDL, 0.02 and 0.22 mg kg ^-1 , respectively. Therefore, it is signified that Aloe vera plant extract is safe to be used as an antimicrobial agent. Hence, throughout impoundment is needed to verify the trace metal levels in plants.