Shrikant A. Bhat

Multi-objective optimisation of metabolic productivity and thermodynamic performance

Novel multi-objective optimisation methodologies, including a two-step sequential optimisation approach and multi-objective optimisation approaches using non-dominated sorting genetic algorithms (NSGAs) and MATLAB based linear programming integrated with genetic algorithms have been developed for the first time to engineer the cellular metabolic productivity and process performance simultaneously. The simultaneous optimisation of cellular metabolic productivity and thermodynamic performance deduces a unique set of enzyme catalysed pathways and flux distributions for a given metabolic product of importance. It has been demonstrated that the energy generating pathways associated to drive a desired productivity are prioritised effectively by multi-objective optimisation approach. A case study on the pentose phosphate pathway (PPP) and glycolysis of in silico Escherichia coli has been used to illustrate the effectiveness of the methodologies.

Some practical aspects of designing a laboratory scale batch polymerization reactor without gas entrapment and interfaced with virtual instrumentation

A 1-1 stainless steel (SS) reactor with a glass bottom has been designed with symmetrically placed internals so that gas entrapment is completely avoided during bulk polymerization of methyl methacrylate (MMA). This reactor is instrumented and controlled using virtual instrumentation. The power consumed by a constant-speed stirrer motor is measured as a function of time which, along with the temperature history, can be used to infer the state (monomer conversion xm and weight average molecular weight Mw) of the viscous reaction mass. This study highlights the importance of symmetry in the design of the reactor, proposes a novel reactor design, and discusses in detail the temperature control configuration that can help track any temperature history. Some preliminary results are reported for bulk polymerization of MMA and a correlation developed for the stirrer power, which can be used for soft sensing.