TABLE 2.
Variation in C, N, O, and H stable isotope ratios of B. subtilis spores
| Element | Avg SD (‰)
|
|||||
|---|---|---|---|---|---|---|
| Instrument precisiona | Duplicate measures of one spore culture (no. of cultures)b | Triplicate cultures produced in same medium and processed in tandem
|
Cultures produced in the same medium but in different production runs with potentially different incubation times
|
|||
| Broth cultures (n = 41) | Agar cultures (n = 20) | Broth cultures (n = 15 media, 49 total) | Agar cultures (n = 8 media, 53 total) | |||
| C | 0.20 | 0.08 (238) | 0.12 | 0.09 | 0.34 | 0.36 |
| N | 0.20 | 0.10 (239) | 0.16 | 0.29 | 0.39 | 0.36 |
| O | 0.20 | 0.20 (245) | 0.25 | 0.27 | 0.71 | 0.79 |
| H | 2.0 | 1.5 (246) | 1.8 | 2.4 | 4.4 | 3.1 |
a
Standard deviation of laboratory reference material measured over time.
b
Broth and agar cultures.