Functional Characterisation of Germinant Receptors in Clostridium botulinum and Clostridium sporogenes Presents Novel Insights into Spore Germination Systems
Figure 5
Germination rates of complemented GR mutants for C. botulinum and C. sporogenes.
Spores were incubated in 20 mM Tris buffer, pH 7.4, amino acid (100 mM) + L-lactate (50 mM) + NaHCO3 (50 mM) at 30°C with L-cysteine (C. botulinum), L-alanine (C. sporogenes). (a) C. botulinum mutant gerXA1-0123− complemented with plasmid pMTL8315esp (gerXA1-0123−esp) or plasmid pMTL8315fdx (gerXA1-0123−fdx). (b) C. sporogenes mutant gerXA3-02217− complemented with plasmid pMTL8315esp (gerXA3-02217−esp) or plasmid pMTL8315fdx (gerXA3-02217−fdx). There were two negative controls. Firstly, the uncomplemented mutant (gerXA1-0123− or gerXA3-02217−), secondly WT spores incubated in 20 mM Tris buffer (pH 7.4) + L-lactate (50 mM) + NaHCO3 (50 mM) only (WT Buffer). Spore germination was confirmed by phase contrast microscopy. Error bars represent the standard deviation of 3 independent experiments. Data labels (right) refer to percentage germination observed by phase contrast microscopy at the end of the experiment.