Scaling Up Plant Molecular Farming via Bioprocessing of Plant Cell Suspension Culture

Large-scale production of recombinant proteins and secondary metabolites is considered a crucial process to meet the increasing demand of the cosmetic, food, and pharmaceutical industries. In plant tissue culture systems, organ cultures such as embryo, shoot, and root cultures along with callus and suspension cultures have been widely used for the production of valuable products. Plant cell suspension culture possesses a higher growth rate than whole plants, easy downstream process, and scalability that make them an ideal platform for the production of recombinant proteins in bioreactors. Molecular farming via plant cell suspension culture has been conducted in various types of bioreactors such as stirred-tank, airlift, bubble column, wave, and membrane bioreactors. However, sensitivity to shear stress, adequate oxygen mass transfer, foaming, and aggregation are still challenging issues for sustainable production due to the specific physiological and rheological properties of plant cells. The control of pH and temperature and mixing and aeration are significant considerations to eliminate those limiting factors on cell viability in advanced systems. This review will provide a comprehensive overview of different bioreactor types, operation conditions, and advanced culture strategies for the large-scale production of recombinant proteins through plant molecular farming in light of current research and developments.