Fig. 2

Pilot-scale fermentation, purification and characterization of scFvCD16A-sc4-1BBL. a Representative two-step fermentation process, including the batch phase and glycerol induction phase. Parameters, such as dissolved oxygen (DO), feeding speed, temperature and pH were monitored during fermentation. b Wet cell weight of scFvCD16A-sc4-1BBL-expressing strains before and after parameters optimization was monitored at indicated time points and represented as mean ± SD from 5 batches. c The expression of scFvCD16A-sc4-1BBL during fermentation was analysed by Western blotting using the same antibody as in Fig. 1c under nonreducing conditions. Left: before parameter optimization; right: after parameter optimization; d The downstream processing workflow of fermentation broth. e The purified scFvCD16A-sc4-1BBL was separated by SDS-PAGE under reducting or nonreducing conditions and identified by Coomassie blue staining or Western blotting. f The purity was determined with SEC-HPLC. M: prestained protein marker