发布时间 :2012-04-23  阅读次数 :2280


报告题目:Anhydrobiosis of Yeasts



报告人:Prof. Alexander Rapoport



Alexander Rapoport, Professor of Microbiology and Biotechnology, Faculty of Biology, University of Latvia; corresponding Member of Latvian Academy of Science; Federation of European Microbiological Societies (FEMS) – Member of Congress Board (2004-2006), Member of Award Board (2006-present), European Federation of Biotechnology, Section for Microbial Physiology


Dehydration of yeasts is widely used at the moment biotechnological process for the obtaining of dry yeast preparations mainly for baking, brewing and wine industries. Nevertheless, investigations of main cell reactions to dehydration still can reveal a lot of information important also for further development of modern biotechnology. The possibility of the maintenance of viability of live organisms in dry state was first discovered by great Dutch naturalist Anthony van Leeuwenhoek in 1701. A lot of disputes and investigations directed to the confirmation of this unusual phenomenon were realized during these 300 years. At the same time only from the last 25 years of 20th century we have started to accumulate the information about main changes which take place in the cells at their dehydration. It was shown that practically all intracellular structures could be subjected to more or less serious changes. Rather important structural-and-functional changes were described for different intracellular membranes, nucleus, vacuoles, peroxisomes, ribosomes and cell wall. A number of intracellular protective reactions which are responsible for the maintenance of the viability of dehydrated cells as well as for the stable quality of microbial preparations was revealed. It was shown that other polyols besides trehalose including also alcohols (glycerol, inositol, sorbitol, xylitol and others) as well as Hsp70 protective system could be very important in these conditions. The possibility to increase “artificially” the resistance of yeast biomass to dehydration treatment was found. These investigations gave us also the possibility to propose physiological engineering as very prospective approach for further developments of different biotechnological processes. The ways for the progress in technologies linked with production of different dry active preparations of industrially valuable microorganisms can be proposed too. Results which were obtained during our investigations of mechanisms of yeasts dehydration can be applied also for the improvement of some other biotechnologies. They can be used, for example, for working out of new methods of immobilization of microorganisms, for the purification and protection of the environment, for the separation of biologically active compounds produced by microorganisms etc.