TABLE 1.
Protocol step | Specific consideration(s) | Method(s) or example(s)a |
---|---|---|
1. Measurement of growth ability under stress | Optimize stress condition by piloting strain variability. | Fig. S1 |
Randomize pilot strains and the testing order of strains. | Functions to generate random numbers without repeats, e.g., in R or Excel | |
Minimize potential technical variation and batch effects: | ||
Use the same growth medium throughout the entire experiment. | Prepare the required amount all at once | |
Have one individual perform all experiments, if possible. | Fig. S4, S5 | |
Utilize within-experiment technical and biological replicates. | Fig. S11 | |
Utilize between-experiment control strains. | Fig. S11 | |
When using Bioscreen, leave the outermost rim of the honeycomb plate blank to avoid test broth evaporation. | Fig. S3, S11 | |
Detect potential contamination and empty wells; retest, if necessary. | Visualize growth curves during or after experiment; culture honeycomb plate wells with unusual growth and no growth | |
Inspect and deal with outliers. | Fig. S2, Text S10: volume 1 | |
Inspect and normalize potential technical variation and batch effects. | Fig. S6–9, Text S10: volumes 2 and 3 | |
2. Selection of a suitable method for growth parameter calculation | Calculate growth parameters using several methods. | Text S10: volume 4 |
Compare the fit and values of the parameter calculation methods. | Text S10: volume 5 | |
3. Comparison of growth patterns between strains | Visualize growth parameters to see overall parameter variation. | Text S10: volume 6 |
Visualize growth curves to see entire growth patterns. | Text S10: volumes 3 and 7 | |
Combine statistical methods and intuitive reasoning to determine a suitable way to quantify strain variability. | Fig. S12–15 | |
4. Biological interpretation of the discovered differences | Classify strain variability and interpret it via growth parameters. | Text S10: volumes 6 and 7 |
Investigate strain variability with biological background variables and draw conclusions. | Data exploration and statistical tests (see Materials and Methods for examples) |
Methods or examples described in the supplemental material published with this article are indicated by their number. Text S10 includes R codes for the data analyses and is divided into volumes 1 to 7 according to their content.