Abstract:
The preservation and maintenance of stock cultures are required
for microbiological pathological biotechnological and research studies. The
laboratories in Universities maintain a series of stock cultures for teaching
purposes. The maintenance of fungal cultures by sub culturing has been a
common practice which involves much time and labour. In this study, two
preservation techniques namely storage under mineral oil and silica gel
storage were carried out to determine the suitability of the techniques for
various fungi. Fungal species Aspergillus, Penicillium, Saprolegnia, Sclerotium,
Cercospora, Colletotrichum, Rhizopus, Helminthosporium, Trichoderma, Curvularia,
Pythium, and Phytophthora were collected from various sources and cultured on
suitable media. The viability of the different fungal cultures was tested by
transferring them onto suitable media every year. Aspergillus, Penicillium,
Rhizopus, Sclerotium, Helminthosporium, Trichoderma and Curvularia species
survived seven years storage in the silica gel method. This method was not
found to be suitable for Pythium and Phytophthora. Aspergillus and Penicillium
remained viable for six years when stored under mineral oil whereas
Saprolegnia, Cercospora, Sclerotium and Colletotrichum needed sub culturing every
two years. Even though sophisticated technology such as liquid nitrogen
storage is available for preservation nowadays, it is very expensive. Thus the
above two methods of preservation of fungi would be beneficial for
laboratories in Universities and schools with limited resources
