High ethanol productivities using small Ca-alginate beads of immobilized cells ofZymomonas mobilis

✍ Scribed by Argyrios Margaritis; Pramod K. Bajpai; J. Blair Wallace

• Publisher: Springer Netherlands
• Year: 1981
• Tongue: English
• Weight: 306 KB
• Volume: 3
• Category: Article
• ISSN: 0141-5492
• DOI: 10.1007/bf00158688

✦ Synopsis

Zymomonas mobilis cells were immobilized into small 1 mm diameter beads of Ca-alginate in order to minimize mass transfer limitations and maximize immobilized cell activity.

A combination of small bead size with a high cell concentration of 58 g dry wt. cell per lit. bead volume resulted in high ethanol productivities using a newly designed ~acked bed bioreactor system. Steady-state dilution rates ranging from OA h-l ~3.9 h -i were run resulting in a maximum productivity of I02 g ethanol/I/h for an inlet substrate concentration of lO0 g glu/l and 87% conversion. The bioreactor was run continuously at a fixed dilution rate for 384 h and short intermittent treatment of the beads with CaCl 2 temporarily increased ethanol productivity to a maximum of ll6 g ethanol/I/h.