Modelling growth kinetics of Streptomyces coelicolor A3(2) in a pressurised membrane gradostat reactor (MGR)

Abstract

Limited information is available with regards to the microbial growth kinetics of Streptomyces coelicolor A3(2) immobilised in pressurised membrane gradostat reactors (MGR). The purpose of this study was to quantify the growth kinetics of the filamentous bacterium immobilised on the external surface of ceramic membranes. The single fibre MGR's (SFMGR) were operated using a pneumatic system to supply humidified pressurised air to the extra capillary space (ECS). The nutrient growth medium was supplied to the lumen of the ceramic membrane in the dead-end mode. The growth curve that was obtained for S. coelicolor A3(2) showed the presence of two growth cycles (biphasic growth) from ±66 to 162 h and ±162 to 354 h, respectively, with no noticeable intermediate lag phase. A faster specific growth rate of 0.049 h−1 was obtained for the first growth cycle, with a lower specific growth rate in the range of ±0.013 to 0.019 h−1 obtained for the second growth cycle. The growth kinetics of S. coelicolor A3(2) within a pressurised MGR has not been reported previously.