Yeast spore wall has a unique multilayer structure, and the first and second outermost layers are composed of dityrosine and chitosan, respectively.Thus, removal of the dityrosine layer by disruption of the DIT1 gene, which is required for dityrosine synthesis, leads to exposure of the chitosan layer at the spore surface.In this way, spores can be made resemble chitosan beads.Our results demonstrate that ditlA spores not only have the ability to adsorb heavy metals and negatively charged molecules, but also can serve as a carrier for immobilization of enzymes.