Fig. 4

Deletion of YER161C (SPT2) increases the alkali tolerance in yeast. a Construction of seamless knockout yeast strains. With two rounds of genome integration, transformants were selected on SC-Ura and 5-FOA medium, respectively. b Verification of targeted deletions by junction PCR. All junction primers were listed in Additional file 1: Table S1. c Verification of individual gene deletions. All primers of individual genes were listed in Additional file 1: Table S1. d Characterization of the knockout yeast strains on YPD medium at pH 8.0. Strains on selective medium were cultured 4 days in 30 °C before photographed. e Growth curves of yML094 and BY4741 at pH 8.3. f Characterization of SPT2 knockout strains under various stressful conditions. g Growth fitness of SCRaMbLEd strains and SPT2 knockout strains at pH 8.0 using NaOH as alkali source. h pH changes of yML094 and BY4741 in liquid YPD medium at pH 8.3