Water activity (aw) and microbes

Microbe minimum aw for growth most molds 0.8 most yeasts 0.85 most gram + 0.9 most gram - 0.93 S. aureus 0.85 Halophilic bacteria 0.75 most foodborne bacteria have no growth below aw of 0.91 growth range also influenced by pH, temperature, oxidation-reduction potential