Improvement of the fermentation performance of Lactobacillus plantarum by the flavanol catechin is uncoupled from its degradation

Aims: To determine the influence of the flavanol catechin on key metabolic traits for the fermentation performance of Lactobacillus plantarum strain RM71 in different media and to evaluate the ability of this strain to catabolize catechin. Methods and Results: Growth monitoring and time course of sugar consumption data tracking in chemically defined medium (CDM), revealed that growth of Lact. plantarum strain RM71 upon catechin was characterized by a noticeable shorter lag period, outcome of earlier sugar consumption and lactic acid production courses. Catechin gave rise to higher cell densities compared to controls because of an increased extension of sugar utilization. Fermentation of media relevant for practical fermentation processes with Lact. plantarum strain RM71 showed that catechin sped up malic acid decarboxylation, which besides quicker and extended consumption of several sugars, resulted in faster and higher lactic acid production and growth. Spectrophotometric evaluation of catechin by HPLC-DAD and the lack of catechin concentration-dependent effects showed that the observed stimulations were uncoupled from catechin catabolism by Lact. plantarum. Conclusions: The flavanol catechin stimulated the growth of Lact. plantarum strain RM71 by promoting quicker sugar consumption, increasing the extension of sugar utilization and stimulating malic acid decarboxylation. These stimulations are uncoupled from catechin catabolism as Lact. plantarum did not catabolize it during fermentation. Significance and Impact of the Study: This study, for the first time, examined the influence of the flavanol catechin on the fermentation performance of a Lact. plantarum strain in several media under different fermentation conditions. The information could be relevant to control the production and obtain high-quality food products fermented by this micro-organism.