An improved temporary immersion bioreactor design for plant tissue culture propagation

Open Access
Author:
Shaw, Sydney E
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Wayne Roger Curtis, Thesis Supervisor
  • Darrell Velegol, Honors Advisor
Keywords:
  • bioreactor
  • tissue culture
  • mass transfer
Abstract:
Temporary immersion bioreactors (TIB) have been used extensively for plant propagation. Nearly all designs have utilized pneumatics (air pressure) to move the culture media either between chambers or between compartments to provide intermittent immersion of the plant tissue. We report here a design that overcomes two disadvantages of typical designs: (1) large volumes of gas use, and (2) a rigid culture vessel. By using a media reservoir that is raised and lowered, the movement of liquid is completely decoupled from gas flow rates. Since the culture vessels are not pressurized, the compartment containing the plant tissue can be constructed from a simple plastic bag. The ability to minimize gas flows provides efficient use of gas mixtures such as elevated oxygen or CO2 to enhance plant tissue culture growth. Liquid flows are observed to induce small but significant suction pressures on the order of several inches of water, which introduces the potential for contamination. This can be overcome by a simple inexpensive manifold design for gas delivery to multiple reactors at very low flow rates. The media reservoir manipulation is accomplished with an inexpensive stepper motor and pulley configuration that includes the ability to provide remote monitoring. Progress on developing this reactor system using seedless watermelon tissue will be presented. The goal of this work is to achieve superior growth to static agar culture (as demonstrated with a rigid flask TIB operated pneumatically) or to achieve similar growth with a system that is more scalable and adaptable than traditional tissue culture.