Dataset: Population Growth

To investigate the population dynamics of isolated symbiont genotypes to temperature, we grew replicate cultures of each of the five genotypes in growth chambers set to 26°C, 30°C, and 32°C. The mean temperatures (+/- 1 s.d.) in the three chambers were 25.5°C (+/- 0.5), 30.1°C (+/- 0.3), and 31.6°C (+/- 0.2).  We initiated 12 replicate cultures of each genotype in sterile flasks with 75mL of sterile f/2 media with 750,000 cells (10,000 cells/mL) from the appropriate stock culture. Replicate cultures of each genotype were randomly distributed among three identical growth chambers (Percival I-36LLVL) set to each of the three temperatures (n=4 replicate cultures of each genotype at each temperature). We systematically rotated the position of cultures in the growth chamber daily to minimize the effect of any small differences in light and temperature within the chamber. Lights were set on a 12:12 day:night cycle, with an average illumination during the day of 4533 (+/- 456) Lux. We performed this experiment in May and July of 2019.

We quantified the density of cells in each culture three times per week using the average of four replicate hemacytometer counts. We fit a growth curve to the density of cells in each replicate over 20 days using the growthcurver package in R (v. 4.0.3) and extracted the maximum growth rate (r) and carrying capacity (K).