Isolation and characterization of B acillus subtilis spores that are superdormant for germination with dodecylamine or C a 2+ ‐dipicolinic acid
Author(s) -
PerezValdespino A.,
Ghosh S.,
Cammett E.P.,
Kong L.,
Li Y.q.,
Setlow P.
Publication year - 2013
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.12125
Subject(s) - spore , germination , dipicolinic acid , bacillus subtilis , endospore , spore germination , biology , chemistry , bacillus (shape) , microbiology and biotechnology , botany , bacteria , genetics
Abstract Aims To isolate and characterize spores superdormant ( SD ) for germination with either Ca 2+ ‐dipicolinic acid ( C a DPA ) or dodecylamine. Methods and Results Bacillus subtilis spores were germinated three times with either C a DPA or dodecylamine and germinated spores removed after each germination treatment, yielding 0·9% ( C a DPA ‐ SD spores) or 0·4% (dodecylamine‐ SD spores) of initial dormant spores. Compared to dormant spores, C a DPA ‐ SD spores germinated poorly with C a DPA and better with dodecylamine and nutrient germinants, although release of DPA from individual C a DPA ‐ SD spores was slow during nutrient germination, and this germination was strongly inhibited by T b C l 3 . The C a DPA ‐ SD spores were sensitive to hypochlorite and had elevated levels of nutrient germinant receptors ( GR s) relative to levels in dormant spores. Dodecylamine‐ SD spores' germination with dodecylamine and nutrients was similar to that of dormant spores, their germination with C a‐ 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 T b C l 3 . Conclusions Ca DPA ‐ SD spores appear to have a coat defect and accompanying low levels of the cortex‐lytic enzyme C wl J . 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.