Yields of superdormant spores with different nutrient germinantsa

Species/strainGerminanteYield (%)
B. subtilis PS533 (wild type)Valineb3.8c
10× LB medium0.7
AGFK plus valineb0.6
Moderate valineb,d58
B. subtilis FB22 (ΔgerA gerBA*)Asparagine-glucose8.7c
10 mM glucose plus low asparagined63
B. subtilis FB87 (ΔgerB ΔgerK)Valineb14.5
B. subtilis PS3665 (ΔgerA gerBB* ΔgerK)Asparagine5.7
B. subtilis PS3710 (ΔgerA gerBA* ΔgerK)Asparagine10.6
B. megaterium (wild type)Glucose3.5c
10× LB medium0.5
Moderate glucosed38
  • a Superdormant spores of various strains were prepared using various nutrients, and the yields of superdormant spores were determined, as described in Materials and Methods.

  • b l-Valine was used in these isolations instead of l-alanine to avoid problems due to inhibition of germination because of generation of inhibitory d-alanine by alanine racemase (5).

  • c These values were determined in triplicate with less than 20% variation in the values obtained.

  • d Isolation of these superdormant spores began with 100 ml of germinating spores at an OD600 of 1.

  • e Normal and moderate nutrient germinant levels are given in Materials and Methods.