Design of different bioreactor configurations: application to ligninolytic enzyme production in semi-solid-state cultivation

Abstract

The production of ligninolytic enzymes by Phanerochaete chrysosporium BKM-F-1767 (ATCC 24725) in laboratory-scale bioreactors was studied. The cultivations were carried out in semi-solid-state conditions, employing corncob as carrier, which functioned both as a place of attachment and as a source of nutrients. Several bioreactor configurations were investigated in order to determine the most suitable one for ligninolytic enzyme production: a 1-dm3-static-bed bioreactor, a 1-dm3-static-bed bioreactor with air diffusers into the bed, a 0.5-dm3-static-bed bioreactor with air diffusers into the bed and a tray bioreactor. Although the static-bed configurations produced maximum individual lignin peroxidase (LiP) activities about 400 U dm−3 (1.0-dm3 bioreactor) and about 700 U dm−3 (0.5-dm3 bioreactor), manganese-dependent peroxidase (MnP) was not detected throughout the cultures. Nevertheless, the tray configuration led to maximum individual MnP and LiP activities of about 200 U dm−3 and 300 U dm−3, respectively. Therefore, this configuration is the most adequate of the different bioreactor configurations tested in the present work, since the ligninolytic complex formed by MnP and LiP is more efficient for its application to bio-processing systems. In addition, the results indicated the influence of the oxygen in ligninolytic enzyme production. © 2001 Society of Chemical Industry