دانلود کتاب پروتکل های آزمایشگاهی در بیولوژی قارچی

Microorganisms are fundamental materials for scientific and practical studies. Culture collections (biological resource centers) play a primary role in the stable preservation and long-term storage of microbial resources and ensure regular access to well-documented strains after a long time from their isolation for scientific or biotechnological use. Various methods of preservation of fungal cultures have been reported. Freeze-drying (lyophilization) and cryopreservation methods are utilized for thousands of fungal strains in microbial collections all over the world. Nevertheless, it is clear that the fungal strains of different species vary in the ability to survive after long-time storage preservation under laboratory conditions. Some of them are very difficult to maintain ex situ, whereas others could be easily and successfully preserved alive by using almost any conservation technique. Storage methods for filamentous fungi result from the type and degree of sporulation. Spore-forming strains (as opposed to nonsporulating strains) can be effectively freeze-dried. Both types can be frozen and stored for long periods in liquid nitrogen or in a low-temperature refrigerator. The experience of long-term preservation of fungal strains shows that the duration of storage directly depends not only on the choice of the method but also on the laboratory protocol and temperature of subsequent cultures storage. This chapter presents the methods of cryopreservation, freeze-drying, drying on silica gel, and preservation in sterile soil that are utilized in VKM fungal collection, accompanied by data on maximal storage time registered. The methods take into consideration the special features of cultures preserved as well as the equipment used. VKM fungal collection (All-Russian Collection of Microorganisms, Russia) was established in 1955 and has a long-term experience in the preservation and storage of fungal cultures. Collection of filamentous fungi is currently composed of approximately 7000 strains (590 genera, 1600 species) belonging to species of the kingdoms Chromista (Oomycota) and Fungi (zygomycetous, ascomycetous and basidiomycetous fungi).