2.2. Microorganisms and Culture Conditions

The Neolentinus lepideus strain BRFM15 studied was deposited in the CIRM-CF collection (International Centre of Microbial Resources dedicated to Filamentous Fungi, INRAE, Marseille, France). It was kept on malt agar slants at 4 °C.

Precultures and cultures of N. lepideus BRFM15 were carried out as previously described by Odinot et al. [41]. In order to induce PAD activity, commercial SA was added to 3-day-old cultures as a filter-sterilized solution at a final concentration of 0.3 g.L⁻¹, and was fed in daily to keep the final concentration in the culture medium at 0.3 g.L⁻¹.

The recombinant strain Aspergillus niger BRFM451 is a feruloyl esterase A (AnFaeA) overproducing strain, formerly engineered in our laboratory from the host strain A. niger D15#26 [42]. In this study, this strain was used to produce batches of AnFaeA enzyme for use in bioconversion trials on biosourced SA from RSM. The culture medium was buffered at pH 5 with a 0.1 M citrate-sodium phosphate buffer, and the production of the recombinant AnFaeA enzyme was triggered by a concentration of 50 g.L⁻¹ glucose [42].