Determination of antimicrobial properties of some commercial vegetable tanning extracts used in leather industry

In this study, we aimed to determine the antimicrobial activity of eight different vegetable tanning extracts commercially used in leather industry, against bacterial and fungal isolates isolated from tannery processes. In order to determine the antimicrobial activity of the tanning extracts, two different concentrations were used (1% and 5%) and the results were compared each other. The antimicrobial activity of the aqueous extracts of the tanning extracts against microorganisms was identified by using the disc diffusion method. The effects of the vegetable tanning extracts on the test microorganisms showed variability. It was observed that tanning extract IV (quebracho extract), tanning extract VII (sulphited valonea extract) and tanning extract II (mimosa extract) were more effective against growing bacteria isolates in NaCl free, 5% NaCl and 10% NaCl mediums, respectively. Tanning extract I (chestnut extract) and II (mimosa extract) were found to be more effective on the growing fungi isolates in 10% NaCl medium while all tanning extracts had no effect on the growing isolates of fungi in NaCl free and 5% NaCl mediums. As a result, it was shown that all of the extracts used in the study were more effective against bacteria rather than fungi, which mean these antibacterial agents.