Degradation of epigallocatechin and epicatechin gallates by a novel tannase TanHcw from Herbaspirillum camelliae

Abstract

Background Herbaspirillum camelliae is a gram-negative endophyte isolated from the tea plant. Both strains WT00C and WT00F were found to hydrolyze epigallocatechin-3-gallate (EGCG) and epicatechin-3-gallate (ECG) to release gallic acid (GA) and display tannase activity. However, no tannase gene was annotated in the genome of H. camelliae WT00C. Results The 39 kDa protein, annotated as the prolyl oligopeptidase in the NCBI database, was finally identified as a novel tannase. Its gene was cloned, and the enzyme was expressed in E. coli and purified to homogeneity. Moreover, enzymatic characterizations of this novel tannase named TanHcw were studied. TanHcw was a secretary enzyme with a Sec/SPI signal peptide of 48 amino acids at the N-terminus, and it catalyzed the degradation of tannin, methyl gallate (MG), epigallocatechin-3-gallate (EGCG) and epicatechin-3-gallate (ECG). The optimal temperature and pH of TanHcw activities were 30 °C, pH 6.0 for MG and 40 °C, pH 7.0 for both EGCG and ECG. Na+, K+ Mn2+ and Triton-X100, Tween80 increased the enzyme activity of TanHcw, whereas Zn2+, Mg2+, Hg2+, EMSO, EDTA and β-mercaptoethanol inhibited enzyme activity. Km, kcat and kcat /Km of TanHcw were 0.30 mM, 37.84 s−1, 130.67 mM−1 s−1 for EGCG, 0.33 mM, 34.59 s−1, 105.01 mM−1 s−1 for ECG and 0.82 mM, 14.64 s−1, 18.17 mM−1 s−1 for MG, respectively. Conclusion A novel tannase TanHcw from H. camelliae has been identified and characterized. The biological properties of TanHcw suggest that it plays a crucial role in the specific colonization of H. camelliae in tea plants. Discovery of the tannase TanHcw in this study gives us a reasonable explanation for the host specificity of H. camelliae. In addition, studying the characteristics of this enzyme offers the possibility of further defining its potential in industrial application.

Application of Phytochemicals To Combat Fungal Pathogens of Pulses: An Approach toward Inhibition of Fungal Propagation and Invasin Activity

“…Our result was consonant with the work of Elslahi et al, Meena et al, and Mishra et al ,, On the contrary, no significant bacterial growth inhibition was observed upon treatment with selected phytochemicals in all concentrations. Though the exact mechanism of the survival strategy of the bacteria in presence of the phytochemicals was not investigated in the present study, previous literature suggested that several soil borne bacteria have the potential to degrade those phytochemicals. − The result advocated the acceptability of the combinatorial phytochemicals in the preservation of stored pulses in a sustainable manner.…”

The applications of epigallocatechin gallate (EGCG)-nanogold conjugate in cancer therapy

“…Regardless of its anticancer properties, EGCG must be stabilized in order to retain them. The degradation in basic or neutral conditions is one of the issues with naked EGCG stability; it may also be subjected to oxidation or auto-oxidation in physiological and gastric conditions [22][23][24][25][26][27][28]. As a result, the stability of EGCG is highly dependent on its local concentration as well as the targeted environment [29,30].…”

Molecular mechanism of high‐production tannase of Aspergillus carbonariusNCUF M8 after ARTP mutagenesis: revealed by RNA‐seq and molecular docking

“…6,8 Recently, studies on the production and enzymatic properties of tannases have received increasing attention. To obtain high-yield strain, researchers have developed high-yield tannase strains through random mutagenesis, 10 gene cloning 11,12 and search for new sources, 13 etc. For instance, Zakipour-Molkabadi et al 10 analyzed the effects of heat treatment and γ-radiation on the tannase production capability of Penicillium sp.…”