These authors contributed equally to this work.
Isolation and characterization of Bacillus subtilis spores that are superdormant for germination with dodecylamine or Ca2+-dipicolinic acid
Article first published online: 29 JAN 2013
© 2013 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 114, Issue 4, pages 1109–1119, April 2013
How to Cite
Perez-Valdespino, A., Ghosh, S., Cammett, E.P., Kong, L., Li, Y.-q. and Setlow, P. (2013), Isolation and characterization of Bacillus subtilis spores that are superdormant for germination with dodecylamine or Ca2+-dipicolinic acid. Journal of Applied Microbiology, 114: 1109–1119. doi: 10.1111/jam.12125
- Issue published online: 18 MAR 2013
- Article first published online: 29 JAN 2013
- Accepted manuscript online: 5 JAN 2013 02:40AM EST
- Manuscript Accepted: 28 DEC 2012
- Manuscript Revised: 24 DEC 2012
- Manuscript Received: 20 NOV 2012
- U.S. Army Research Office
- Department of Defense Multi-disciplinary University Research Initiative
- U.S. Army Research Laboratory. Grant Number: W911NF-09-1-0286
- Bacillus ;
- bacterial spores;
- spore germination;
To isolate and characterize spores superdormant (SD) for germination with either Ca2+-dipicolinic acid (CaDPA) or dodecylamine.
Methods and Results
Bacillus subtilis spores were germinated three times with either CaDPA or dodecylamine and germinated spores removed after each germination treatment, yielding 0·9% (CaDPA-SD spores) or 0·4% (dodecylamine-SD spores) of initial dormant spores. Compared to dormant spores, CaDPA-SD spores germinated poorly with CaDPA and better with dodecylamine and nutrient germinants, although release of DPA from individual CaDPA-SD spores was slow during nutrient germination, and this germination was strongly inhibited by TbCl3. The CaDPA-SD spores were sensitive to hypochlorite and had elevated levels of nutrient germinant receptors (GRs) relative to levels in dormant spores. Dodecylamine-SD spores' germination with dodecylamine and nutrients was similar to that of dormant spores, their germination with Ca-DPA was slower than that of dormant spores, and these SD spores' GR levels were lower than in dormant spores. However, dodecylamine-SD spores were not sensitive to hypochlorite, and the nutrient germination of these SD spores was only partially inhibited by TbCl3.
CaDPA-SD spores appear to have a coat defect and accompanying low levels of the cortex-lytic enzyme CwlJ. The defect in dodecylamine-SD spores, however, is not clear.
Significance and Impact of the Study
The results suggest that triggering germination by non-GR-dependent germinants is a potential strategy for efficient spore inactivation.