Culture of photomixotrophic soybean and pine in a modified fermentor using a novel impeller

Abstract

Photomixotrophic suspensions of Glycine max (soybean) and Pinus elliottii (slash pine) have been successfully cultured in a hybrid stirred tank photobioreactor using a novel cell-lift impeller. A cell-lift impeller exhibited cell viabilities over 90% and an average cell aggregate size of 1.0 mm or less. Flat-bladed turbines produced equivalent biomass to the cell-lift impeller, but cell viability was reduced (85%) and cell aggregate size increased (3-5 mm diameter). Maximum fresh weights of 82 g L(-1) (soybean) and 52 g L(-1) (slash pine) were achieved in 15 days using continuous lighting (90-100 microE m(-2) s(-1)) and supplemental 2% CO(2) inlet gas. Maximum biomass was achieved using an impeller speed of 60 rpm with air-flow rate of 0.2 vvm for the cell-lift impeller and the pair of flat bladed turbines. The lag and early exponential phases were characterized by (1) rapid hydrolysis of sucrose followed by preferential use of glucose and (2) a reduction in chlorophyll levels. Carbon dioxide (2%-5%) was an essential nutrient for photomixotrophic cell culture in the bioreactors.

A hybrid bioreactor for high density cultivation of plant cell suspensions

“…This hybrid bioreactot can solve the problems found in air-lift fermentor operations, such as limitation in obtaining high cell density and reduction of product formation due to excessive gas-stripping (Scragg et al 1987), without losing its advantages since it has better mixing, more space to prevent cell clumping, and requires a lower gas flow. Most recently, Treat et al (1989) developed a similar bioreactor using a cell-lift impeller. They also used a ceramic air stone which produced small bubbles.…”

“…Panda et al (1989) recently reviewed various currently used bioreactors and discussed criteria for choosing a bioreactor type for optimal growth and metabolite production. In general, no one system is likely to be applicable to all sorts of plant cells and the choice of bioreactor is strongly dependent upon the type of plant cell culture used and the purpose of the experiment (Treat et al 1989).…”

Light-Induced Chloroplast Differentiation in Soybean Cells in Suspension Culture

“…Also, photoautotrophically grown SB-P cells show rates of photosynthetic 02 evolution comparable to that of mature C3 mesophyll leaf cells (21 (24). Thus, SB-P cells provide a novel and easily manipulable system for the study of higher plant chloroplast differentiation as well as dedifferentiation under defined conditions.…”

The production of aromas by plant cell cultures

“…In order to maintain good mixing at low shear rates the standard microbial stirred tank bioreactor was operated either at reduced impeller speeds or with a modified impeller. Many types of modified impellers have been used, and these include inclined blade turbine [91], anchor, helical [92], Intermig [88], sail [93], gate [94] and cell lift [95] (Fig. 6).…”