Antibacterial activity of wood vinegars from Tamarindus indica, Mangifera indica and Azadirachta indica

The finding of new antibacterial agents for an alternative treatment is an urgent issue. Wood vinegar is a condensed acidic liquid, which obtained during the processing of wood charcoal production and used to control animal diseases. Three wood vinegars from each plant including Tamarindus indica, Mangifera indica and Azadirachta indica was evaluated for the antibacterial activities using agar disc diffusion and broth microdilution methods and the mode of action of each wood vinegar determined by scanning electron microscope. Three wood vinegars showed broad-spectrum antibacterial activity against both gram-positive and gram-negative pathogenic bacteria. The minimum inhibitory concentration and minimum bactericidal concentration values were similar with ranging from 1.25-6.25 %v/v. The electron micrographs of cells treated with each wood vinegar showed the similar activity by the disruption of cell membrane in both gram-positive and gram-negative pathogenic bacteria. Microstructural observations showed that wood vinegars depleted of the content of bacterial cells, indicating that the cell structures of treated bacteria were severely affected and damaged by the antibacterial agents. The treated cells showed an incomplete and deformed shape of the cells when compared with the untreated cells. A pH value in culture condition may affect the conformation of the bacterial cell driven by the ATPase energy-consuming pump in bacterial cell membrane [1],[2],[3]. Moreover, wood vinegar exhibited a pH in acidic value. Wood vinegar may target on a bacterial cell membrane. It revealed that T. indica, M. indica and A. indica wood vinegars may be developed for an alternative antibacterial agent to control pathogenic bacteria.

• References

• 1 Chen Y, Montville TJ. Efflux of ions and ATP depletion induced by pediocin PA-1 are concomitant with cell death in Listeria monocytogenes Scott A. J Appl Microbiol Biochem 1995; 79 (06) : 684-690
• 2 Lambert RJW, Skandamis PN, Coote PJ, Nychas GJ. A study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. J Appl Microbiol 2001; 91 (03) : 453-462
• 3 Turgis M, Han J, Caillet S, Lacroix M. Antimicrobial activity of mustard essential oil against Escherichia coli O157: H7 and Salmonella typhi . Food Control 2009; 20 (12) : 1073-1079