Glycerol spores are formed when bacteria are exposed to glycerol. This interferes with the growth of the bacteria, causing it to form a spore. However, the spore formed does not have the thick peptidoglycan layer that is found on a myxospore.
Excess membrane is converted to lipid droplets, and glycerol spores have much thinner membranes – which are susceptible to sonication, and generally less resistant to stresses.
It is easier to produce uniform glycerol spores, and so they have been studied more than traditional spores. However, they are not a complete substitute for fruiting body spores.
Glycerol spores do form quickly – within 60 minutes, making them easy to study.