FIG 5.

Selection of K. marxianus strains with combined beneficial traits. (A) Selection strategy. Km19 and Km17 were crossed, sporulated, and then germinated at 44°C to select for thermotolerant segregants. Single segregants were isolated and tested for lipid production, transformability, and high-temperature growth. (B) Fatty acid percentage in dry cell weight (DCW) for several segregants from the Km17 × Km19 cross and the parental strains. Three segregants have similar profiles to the more lipogenic parental strain (Km19). Experiments are from biological triplicates with mean and standard deviation shown. (C) Growth curves at 45°C for the segregants 4B, 5E, and 2G, as well as parental strains Km17 and Km19, in biological triplicate. Km19 is unable to grow at this temperature. Growth curves for parental strains at 30, 37, and 42°C can be found in the supplemental material (Fig. S7A), as well as for segregants at 30 and 37°C (Fig. S7B). (D) Transformation efficiency for several segregants normalized by Km17 transformation efficiency. Experiments are from 2 to 4 biological replicates with normalized mean and standard deviations shown.