ABSTRACTLactobacillus plantarumis frequently isolated from the fermentation of plant material where tannins are abundant.L. plantarumstrains possess tannase activity to degrade plant tannins. AnL. plantarumtannase (TanBLp, formerly called TanLp1) was previously identified and biochemically characterized. In this study, we report the identification and characterization of a novel tannase (TanALp). While all 29L. plantarumstrains analyzed in the study possess thetanBLpgene, the genetanALpwas present in only four strains. Upon methyl gallate exposure, the expression oftanBLpwas induced, whereastanALpexpression was not affected. TanALpshowed only 27% sequence identity to TanBLp, but the residues involved in tannase activity are conserved. Optimum activity for TanALpwas observed at 30°C and pH 6 in the presence of Ca2+ions. TanALpwas able to hydrolyze gallate and protocatechuate esters with a short aliphatic alcohol substituent. Moreover, TanALpwas able to fully hydrolyze complex gallotannins, such as tannic acid. The presence of the extracellular TanALptannase in someL. plantarumstrains provides them an advantage for the initial degradation of complex tannins present in plant environments.
Uncovering the Lactobacillus plantarum WCFS1 Gallate Decarboxylase Involved in Tannin Degradation
