Fig. 4

Isolation of cellulase hyperproducers from T. reesei transformed with a mixture of six plasmids by FACS directed by surface-displayed DsRed. a Microscopic observation of the T. reesei hyphae displaying DsRed on cell surface. T. reesei was cultivated at 28 °C for 24 h in MM-lactose/sophorose. b FACS isolation of germinated spores from T. reesei surface-displaying DsRed. T. reesei was transformed with a pool of six plasmids for overexpressing bip1, hac1, ftt1, sso2, sar1, and ypt1, respectively. Sixty germlings with the brightest DsRed signal (top 0.1%) were isolated. The area in box was the gating strategy used to delineate the brightest DsRed signal cell populations. c, d Representative strains isolated by FACS produced more endoglucanase (c) and secreted more proteins (d)