TABLE 2.

Variation in C, N, O, and H stable isotope ratios of B. subtilis spores

ElementAvg SD (‰)
Instrument precisionaDuplicate measures of one spore culture (no. of cultures)bTriplicate cultures produced in same medium and processed in tandemCultures 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)
C0.200.08 (238)0.120.090.340.36
N0.200.10 (239)0.160.290.390.36
O0.200.20 (245)0.250.270.710.79
H2.01.5 (246)1.82.44.43.1
  • a Standard deviation of laboratory reference material measured over time.

  • b Broth and agar cultures.