Kinetics and Production of Rhamnolipid from Pseudomonas sp. TMB2 in Shake-Flask and Fabricated Batch Reactor

Rhamnolipid producing Pseudomonas sp. TMB2 was selected for this investigation to optimize the metabolite production in fabricated batch reactor after studying yield kinetics in shake-flask and tried to reduce the overall production cost through In-situ recovery technology. Using various kinetic models, maximum specific growth rate (μmax) and half velocity constant (KS) of TMB2 were determined to be 0.185 ± 0.0025 h−1 and 0.124 ± 0.024 g/L in shake-flask, respectively. Further, a batch reactor was designed with integration of a foam fractionate column in the lid of the vessel and their performances were compared with shake-flask studies. The yields of rhamnolipids production on biomass (YP/X), rhamnolipids production on substrate (YP/S) and biomass production on substrate (YX/S) were found to be higher in reactor than that of shake-flask. The best conditions for maximum rhamnolipid production in reactor were observed to be 2 vvm and 300 rpm, giving YP/S = 0.152 g/g, YP/X = 0.542 g/g and YX/S = 0.280 g/g. Rhamnolipid production was increased by ≈ 10.18% in the reactor than that of shake-flask in optimized conditions. Rhamnolipid concentrations in the foamate were also found to be higher than that of reactor vessels. Further, the performance of foam fractionation was validated through enrichment and recovery, which were found in the range of 2.75–4.86 and 25.33–64.64%, respectively.