Four new fermenters were designed and constructed for use in secondary metabolite cultivations, bioconversions, and enzyme production. A new PC/PLC-based control system also was implemented using GE Fanuc PLCs, Genius I/O blocks, and Fix Dynamics SCADA software. These systems were incorporated into an industrial research fermentation pilot plant, designed and constructed in the early 1980s. Details of the design of these new fermenters and the new control system are described and compared with the existing installation for expected effectiveness. In addition, the reasoning behind selection of some of these features has been included. Key to the design was the goal of preserving similarity between the new and previously existing and successfully utilized fermenter hardware and software installations where feasible but implementing improvements where warranted and beneficial. Examples of enhancements include strategic use of Inconel as a material of construction to reduce corrosion, piping layout design for simplified hazardous energy isolation, on-line calculation and control of nutrient feed rates, and the use of field I/O modules located near the vessel to permit low-cost addition of new instrumentation.

An ambient loop USP puri®ed water system has been designed and implemented using carbon and ion exchange resin beds, ultraviolet light systems and polishing ®lters to produce water consistently meeting or exceeding all USP XXIII quality speci®cations for puri®ed water. The circulation system is constructed of PVDF plastic piping material installed in a continuous fullydrainable loop. The system was sized for a pilot scale fermentation/harvest process at the 1000 l cultivation scale. This system passed all installation and operational quali®cation testing as well as sixty days of continuous performance quali®cation testing before entering into an ongoing monitoring regimen. Excursions outside acceptable water quality parameters during this extensive monitoring regimen were minimal. Sanitization of the system, along with bed and ®lter changes at the time of sanitization, was conducted every 3 to 6 months to insure consistent water quality.