P38: Real-time bioprocess monitor for on-line measurement and control

Analytical sensing technologies that can measure key chemicals in real-time during cell expansion and protein expression phases of upstream processes has been of interest to the biotechnology community for some time.  The driving goal, in addition to enhanced process efficiency, is consistent product quality through discovery, process development, scale up, and manufacturing.  Real-time chemical monitoring is recognized to be particularly important during upstream processes, where complex multicomponent parameters including media composition, dissolved oxygen levels, and reactor scale are known to impact product quality.

A novel on-line bioprocess monitor is presented for the simultaneous, real-time measurement of glycerol and methanol and the tracking of cell density during production of recombinant protein from Pichia pastoris.  This automated monitor uses a completely sealed and sterilized closed loop to continuously circulate a small sample from the bioreactor through the monitor and back to the bioreactor.  There is zero sample lost from monitoring because the near infrared measurement method is completely nondestructive.  In contrast with some previous approaches, very little operator expertise is required.  The monitor is calibrated prior to installation and then tuned to the user’s specific process.  Operation is a simple process of injecting a set of standard solutions, waiting a minute while data are collected for each solution, connecting the sterilized process loop from the bioreactor, and begin collecting quantitative data.   The monitor’s solid-state construction is rugged and designed for industrial use.  Results will be presented showing robust operation and accurate monitoring during Pichia fermentation runs for more than 6 months post-calibration.