Growth kinetics and scale-up of Agrobacterium tumefaciens.

Abstract

Production of recombinant proteins in plants through Agrobacterium-mediated transient expression is a promising method of producing human therapeutic proteins, vaccines, and commercial enzymes. This process has been shown to be viable at a large scale and involves growing large quantities of wild-type plants and infiltrating the leaf tissue with a suspension of Agrobacterium tumefaciens bearing the genes of interest. This study examined one of the steps in this process that had not yet been optimized: the scale-up of Agrobacterium production to sufficient volumes for large-scale plant infiltration. Production of Agrobacterium strain C58C1 pTFS40 was scaled up from shake flasks (50-100mL) to benchtop (5L) scale with three types of media: Lysogeny broth (LB), yeast extract peptone (YEP) media, and a sucrose-based defined media. The maximum specific growth rate (μ max) of the strain in the three types of media was 0.46±0.04h-1 in LB media, 0.43±0.03h-1 in YEP media, and 0.27±0.01h-1 in defined media. The maximum biomass concentration reached at this scale was 2.0±0.1, 2.8±0.1, and 2.6±0.1g dry cell weight (DCW)/L for the three media types. Production was successfully scaled up to a 100-L working volume reactor with YEP media, using k L a as the scale-up parameter.