string: As the exosporium has been shown to confer a high proportion of the hydrophobic characteristic to the endospore, it is possible that as endospores persist in the environment the exosporium becomes damaged leading to a reduction in hydrophobicity and increased dilution of calcium from the core (Koshikawa et al. 1989; Faille et al. 2007; Faille et al. 2010; Williams et al. 2012).