Anhydrobiosis in Non-conventional Yeasts

Abstract

Anhydrobiosis is a unique state of living organisms that provides the possibility of surviving conditions of extreme heat and drought with temporary and reversible suspended processes of metabolism. Beyond its ecological importance in nature, it is used for the production of viable dry microbial preparations, including active dry yeast. During the last decade, this state has also been studied in non-conventional yeasts (NCY), mainly because of the necessity of active dry wine yeasts. At the same time, many other modern biotechnological processes are also linked to the use of NCY. Correspondingly, this implies an interest in the long-term maintenance of various species of NCY in a viable dry state. This review describes the results of studies of the dehydration of various NCY species. It demonstrates the very important contribution of these yeasts to the development of our knowledge of this unique phenomenon of nature. The results of the structural and biochemical investigations of NCY have revealed the main cell changes during their dehydration-rehydration, as well as the intracellular protective reactions necessary for the maintenance of yeast cell viability. The synthesis of various intracellular protective compounds was shown in NCY cells under the conditions of their dehydration-rehydration. All of this accumulated information is important for the development of new approaches for the successful production and use of biotechnologically important species of NCY in an active dry state, as well as for the improvement of our knowledge of the mechanisms of anhydrobiosis.