Microfiltration cell-recycle pilot system for continuous thermoanaerobic production of exo-β-amylase

✍ Scribed by André Nipkow; J. Gregory Zeikus; Philipp Gerhardt

• Book ID: 102765240
• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 923 KB
• Volume: 34
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260340808

✦ Synopsis

A microfiltration cell-recycle pilot-scale system was developed comprised of a conventional continuous-flow fermentor connected t o an in situ steam-sterilizable cross-flow ceramic filter with a backflushing device. A microcomputer was used to control filtration pressure, tangential flow velocity, and backflushing. Performance of the system was tested with the anaerobic production of thermostable extracellular p-amylase a t 60°C by Clostridium thermosulfurogenes on maltose or maltodextrin media. Filtration rates during continuous cultivation were between 20 and 60 L/m2/h. The maltodextrin and cell debris occurring at high retentate flow rates or filtration pressures impaired the performance of the filter. Backflushing initially improved the permeate flux to 42% in a maltose medium and to 10% in a maltodextrin medium, but the effect diminished with time. The productivity of p-amylase (as much as 48 U/mL/h) and concentration of biomass (as much as 14 g/L) were increased 11-and 12-fold, respectively, if compared to values obtained in a chemostat. The concentration of p-amylase rose to 220 U/mL in the reactor, which was 5.5-fold more than under comparable conditions in a chemostat.