The use of esterase genes: a biotechnological strategy to increase the bioavailability of dietary phenolic compounds in lactic acid bacteria.

In the metabolism of hydroxybenzoic and hydroxycinnamic acid derivatives follows a similar two-step pathway, an esterase action followed by a decarboxylation. The esterase genes involved in these reactions have been cloned into pNZ8048 or pT1NX plasmids and transformed into technologically relevant lactic acid bacteria. None of the strains assayed can hydrolyse methyl gallate, a hydroxybenzoic ester. The presence of the tannase encoding genes ( or ) on these bacteria conferred their detectable esterase (tannase) activity. Similarly, on hydroxycinnamic compounds, esterase activity for the hydrolysis of ferulic acid was acquired by lactic acid bacteria when esterase (JDM1_1092) was present. This study showed that the heterologous expression of esterase genes involved in the metabolism of phenolic acids allowed the production of healthy compounds which increase the bioavailability of these dietary compounds in food relevant lactic acid bacteria.