Water content and size of spore components determined by laser diffractometry

For the first time laser diffractometry was used to obtain the refractive index distribution within individual cells in an aqueous environment, allowing accurate determination of their compartmental water content. For bacterial spores the results demonstrated the existence of a dehydrated protoplast surrounded by a less dehydrated integument, thus accounting for the extreme heat resistance of the spores. In contrast, the presence of a dry wall surrounding a water-rich protoplast was shown in fungal spores.