Figure 6.

CC-1690 and CC-5325 recovered from liquid nitrogen freezing equally well. (a,b) Representative images of CC-1690 and CC-5325 after thawing from liquid nitrogen freezing. (c) Cell viability before and after freezing quantified by the No. of colonies on TAP plates. (d) Colony area on TAP plates for cells before and after freezing, normalized to the total number of cells spotted for each condition. The numbers of intact cells before and after freezing in liquid cultures were measured using a Coulter Counter and diluted cultures were spotted on TAP plates. TAP plates with algal spots were grown at 25 °C under 150 μmol photons m⁻² s⁻¹ white LED lights for 44-h before plate imaging. Colony numbers and areas were quantified using ImageJ. Cell viability was calculated by the No. of colonies on TAP plates divided by the No. of cells spotted. Mean ± SE, N = 3 biological replicates. Statistical analyses were performed using a two-tailed t-test assuming unequal variance by comparing the two strains under the same experimental conditions. No significant differences between these two strains under the same conditions; ns, not significant, p > 0.05.