Figure 6.

Generation of a markerless SPD1 knockout strain using nitrate capability for pre-selection. (A) The SPD1 locus was edited in the strain UVM4 using a marker-less donor-DNA containing stop codons and a BamHI restriction site together with the plasmids pMN24 (NIT1) and pMN68 (NIT2) [72,73] for pre-selection on nitrate containing agar plates. (B) Growth performance of ΔSPD1 mutant strains in nitrate containing TAP medium compared to the N-UVM4 strain. Cell concentration over the course of the cultivation is shown (left) as well as biomass dry weight at day four (right). The four best performing strains regarding biomass formation are also shown separately. Error bars represent the standard deviation of indicated biological replicates. Asterisks (*) indicate the significance level of an unpaired, two-sided Student’s t-test assuming non-homogenous variances (*: p < 0.05).