Vulnerability of Bacillus spores and of related genera to physical impaction injury with particular reference to spread‐plating

AIMS: To examine whether bacterial spores are vulnerable to impaction injury during standard spread‐plating or to other modes of physical impaction. METHODS AND RESULTS: Employing heat‐challenged spores of Bacillus pumilus, Bacillus subtilis, Bacillus thuringiensis, Lysinibacillus, Paenibacillus and Brevibacillus spp. from day‐4 to day‐10 nutrient agar (NA) plates in 50% ethanol, plating the spore suspension to the extent of just drying the agar surface on fresh NA (50–60 s; SP‐B) was tested in comparison with the spreader‐independent approach of spotting‐and‐tilt‐spreading (SATS), or a brief plating (