Premium
Analysis of broth‐cultured Bacillus atrophaeus and Bacillus cereus spores
Author(s) -
Buhr T.L.,
McPherson D.C.,
Gutting B.W.
Publication year - 2008
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/j.1365-2672.2008.03899.x
Subject(s) - spore , bacillus cereus , cereus , bacillus subtilis , bacillales , bacillus (shape) , microbiology and biotechnology , bacterial spore , biology , endospore , food science , chemistry , bacteria , genetics
Aims: To compare physical properties of spores that were produced in broth sporulation media at greater than 10 8 spores ml −1 . Methods and Results: Bacillus atrophaeus reproducibly sporulated in nutrient broth (NB) and sporulation salts. Microscopy measurements showed that the spores were 0·68 ± 0·11 μ m wide and 1·21 ± 0·18 μ m long. Coulter Multisizer (CM3) measurements revealed the spore volumes and volume‐equivalent spherical diameters, which were 0·48 ± 0·38 μ m 3 and 0·97 ± 0·07 μ m, respectively. Bacillus cereus reproducibly sporulated in NB, sporulation salts, 200 mmol l −1 glutamate and antifoam. Spores were 0·95 ± 0·11 μ m wide and 1·31 ± 0·17 μ m long. Spore volumes were 0·78 ± 0·61 μ m 3 and volume‐equivalent spherical diameters were 1·14 ± 0·11 μ m. Bacillus atrophaeus spores were hydrophilic and B. cereus spores were hydrophobic. However, spore hydrophobicity was significantly altered after treatment with pH‐adjusted bleach. Conclusions: The utility of a CM3 for both quantifying Bacillus spores and measuring spore sizes was demonstrated, although the volume between spore exosporium and spore coat was not measured. This study showed fundamental differences between spores from a Bacillus subtilis ‐ and B. cereus ‐group species. Significance and Impact of the Study: This is useful for developing standard methods for broth spore production and physical characterization of both living and decontaminated spores.