HPLC analysis of tannic acid degradation by L. plantarum cultures. Modified basal medium containing 1 mM tannic acid was inoculated with L. plantarum strains (WCFS1, ATCC 14917T, NC8, CECT 749, and RM 35) and incubated for 10 days. A noninoculated control medium was incubated under the same conditions. Detection was performed at 280 nm. AU, absorbance units.