Exploration of Mangrove Endophytes as Novel Sources of Tannase Producing Fungi

Tannase, a highly adaptive biocatalyst, plays a pivotal role in diverse bioconversion reactions in nature. This enzyme exhibits numerous applications across various industrial sectors, including food, pharmaceuticals, chemicals, and beverages. This study aimed to screen and characterize fungal endophytes isolated from mangrove plants for their enzyme tannase-producing ability. Eighty-five filamentous endophytic fungi were isolated from different mangrove samples and subsequently identified. These fungal strains were initially screened using the tannic acid agar plate method. Out of the screened strains, 13 fungal isolates demonstrated tannase production ability. The quantitative estimation of extracellular tannase was performed using the submerged fermentation technique. Among the studied endophytes, eight isolates, namely LV_084 (21.21 IU/mL), LV_074 (15.41 IU/mL), LV_078 (6.98 IU/mL), LV_038 (6.97 IU/mL), LV_077 (6.32 IU/mL), LV_016 and LV_066 (6.37 IU/mL), and LV_060 (6.18 IU/mL) exhibited excellent tannase activity. Among these isolates, LV_084 <i>Phyllosticta capitalensis</i> and LV_074 <i>Aspergillus chevalieri</i> showed the highest enzyme-producing ability. These isolates were authenticated using ITS rDNA sequencing, followed by BLAST search and phylogenetic analysis. Furthermore, the physical and chemical conditions for the maximum enzyme production were optimized. This is the first report of enzyme tannase production by <i>Phyllosticta capitalensis</i> and <i>Aspergillus chevalieri</i>.