Analysis of the slow germination of multiple individual superdormant Bacillus subtilis spores using multifocus Raman microspectroscopy and differential interference contrast microscopy
Article first published online: 23 JAN 2012
© 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 112, Issue 3, pages 526–536, March 2012
How to Cite
Zhang, P., Kong, L., Wang, G., Scotland, M., Ghosh, S., Setlow, B., Setlow, P. and Li, Y.-Q. (2012), Analysis of the slow germination of multiple individual superdormant Bacillus subtilis spores using multifocus Raman microspectroscopy and differential interference contrast microscopy. Journal of Applied Microbiology, 112: 526–536. doi: 10.1111/j.1365-2672.2011.05230.x
- Issue published online: 9 FEB 2012
- Article first published online: 23 JAN 2012
- Accepted manuscript online: 28 DEC 2011 03:26PM EST
- 2011/1805: received 20 October 2011, revised 19 December 2011 and accepted 22 December 2011
- spore germination;
- superdormant spores
Aim: To analyse the dynamic germination of hundreds of individual superdormant (SD) Bacillus subtilis spores.
Methods and Results: Germination of hundreds of individual SD B. subtilis spores with various germinants and under different conditions was followed by multifocus Raman microspectroscopy and differential interference contrast microscopy for 12 h and with temporal resolutions of ≤30 s. SD spores germinated poorly with the nutrient germinant used to isolate them and with alternate germinants targeting the germinant receptor (GR) used originally. The mean times following mixing of spores and nutrient germinants to initiate and complete fast release of Ca-dipicolinic acid (CaDPA) (Tlag and Trelease times, respectively) of SD spores were much longer than those of dormant spores. However, the ΔTrelease times (Trelease−Tlag) of SD spores were essentially identical to those of dormant spores. SD spores germinated almost as well as dormant spores with nutrient germinants targeting GRs different from the one used to isolate the SD spores and with CaDPA that does not trigger spore germination via GRs.
Conclusions: Since (i) ΔTrelease times were essentially identical in GR-dependent germination of SD and dormant spores; (ii) rates of GR-independent germination of SD and dormant spores were identical; (iii) large increases in Tlag times were the major difference in the GR-dependent germination of SD as compared with spores; and (iv) higher GR levels are correlated with shorter Tlag times, these results are consistent with the hypothesis that low levels of a GR are the major reason that some spores in a population are SD with germinants targeting this same GR.
Significance and Impact of the Study: This study provides information on the dynamic germination of individual SD spores and improves the understanding of spore superdormancy.