Nutrient manipulation as a basis for enzyme production in a gradostat bioreactor

Nutrient gradients and a supplemented production medium were manipulated using a membrane gradostat bioreactor for the continuous production of manganese peroxidase (MnP) from immobilised Phanerochaete chrysosporium. A production medium containing Tween 80, soybean asolectin and lecithin was developed and tested on batch vessels and evaluated on a continuous single capillary membrane gradostat reactor (SCMGR). The enzyme productivity profile in response to the oxygenation conditions and nutrient feed composition is reported and the attendant effects of the nutrient additives on the morphology and physiology of the fungus are also described. MnP activity was found to increase by 58.16% in stationary batch cultures and an increased MnP productivity of 88.15% was observed after continuous operation with the SCMGR. The phospholipid rich production medium also stimulated intracellular organelles involved in respiration and protein synthesis, and increased biofilm development radially across the membrane support matrix.