Effect of ozone on spore germination, spore production and biomass production in two Aspergillus species

The ability of ozone gas to reduce food spoilage is relatively well documented, but the developmental effects of the gas on food spoilage fungi are not well known. In this study two model aspergilli, Aspergillus nidulans and Aspergillus ochraceus were used to study the effects of ozone on spore germination, sporulation and biomass production. These effects were examined under three levels of ozone; two high level ozone exposures (200 and 300 μmol mol−1) and one low level exposure (0.2 μmol mol−1). The two species behaved noticeably different to each other. Ozone was more effective in reducing growth from spore inocula than mycelia. No spore production could be detected in A. nidulans exposed to continuous low level O3, whereas the same treatment reduced spores produced in A. ochraceus by 94%. Overall the work suggests that ozone exposure is an effective method to prevent spread of fungal spores in a food storage situation.