Fig. 1

Schematic workflow for exploring the secretion capacity for antibody fragments of different mutant strains. a Three yeast strains evolved for significantly improved protein secretion based on α-amylase production. AAC, parental strain; MH34, intermediate strain; B184, highest level α-amylase secreting strain. b Strains after elimination of α-amylase plasmid from the mutant strains. LA, derived from AAC; MA, derived from MH34; HA, derived from B184. c Three new plasmids generated by inserting the three different antibody fragments genes (Nan, Pex and Ran) into the CPOTud vector, respectively. d Strains harboring plasmids for expression of Nan, Pex and Ran, respectively. Nine strains (LA.Nan, LA.Pex, LA.Ran, MA.Nan, MA.Pex, MA.Ran, HA.Nan, HA.Pex, and HA.Ran) were thus generated. e A series of functional analysis experiments was performed after shake flask fermentations of the strains harboring the different expression plasmids. f RNA-seq data were collected and integrated, resulting in an overall biological interpretation of antibody fragment production