2. Damage of Cell Membrane of Aquaspirillum metamorphum as a Result of L-drying and a Role of Ethylenediamine as a Protectant(Papers presented at the 35th Annual Meeting, April, 1989, Tokyo)

Abstract

The damage of cell membrane as a result of L-drying and the protective effect of ethylenediamine on the damage were studied. The strain examined was Aquaspirillum metamorphum IFO 13960 which was susceptible to damage by L-drying. When this strain was dried and rehydrated with phosphate buffer, a large amount of cell components, such as RNA, proteins, and fatty acids were released into the rehydration fluid from the cells. Denatured or degradated proteins which were not found in vegetative cell envelopes appeared in the protein profiles of cell envelopes from rehydrated cells on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Furthermore, the amount of a few glycoproteins which were considered to be located in cell surface markedly decreased. When magnesium sulfate (0.1%) was added to rehydration fluid, the release of cell components and damage of cell envelope proteins were prevented, whereas the degradation of glycoproteins was not. Ethylenediamine had high protective activity on the survival of this strain after L-drying. Addition of ethylenediamine (0.4%) to a medium for drying prevented the release of cell components and the damage of cell envelope protein including the glycoproteins. These results indicate that ethylenediamine prevents the damage of cell envelope protein at the drying step, and magnesium sulfate prevents the damage occurred at the rehydration step.