Microorganisms are interpreted here to include algae, bacteria, fungi, protozoa, and viruses. They are universal and fundamental elements of biotic diversity. Microbes are essential to the maintenance of stable ecosystems and the very existence of plant and animal life. Thus, on-site microbial diversity can only be sustained by maintenance of intact ecosystems. It is estimated that less than 20% of the world’s microbes have been cultured and identified so far.
Microbial germplasm is extremely diversified. The genes that contribute to inheritable germplasm differ even from one strain to another within a species. Genetic variability within and among species is substantial. Species cannot be adequately studied or assessed without growing them in pure culture.
Microbes have an inherent tendency to mutate, which is accelerated under laboratory conditions. Among pure cultures, no cell population is genetically identical to the parent culture. Consequently, culture collections have been and are being established to conserve valuable germplasm important to economic, medical, agricultural, and scientific endeavors. Conservation technologies for microbial cultures are now an integral part of both basic and applied microbiology. Unfortunately, there is no method yet for the complete preservation of genotypes.
The worldwide program for conserving microbial gene pools and making them accessible to both the developed and developing countries has been launched through the establishment of the Global Network of Microbiological Resources Centers (MIRCENS). Today, this network program is comprised of 15 centers in various regions of the world.
No one knows exactly how many culture collections of microbial germplasms exist. The 1986 edition of the World Directory of Collections of Cultures of Microorganisms lists 327 collections in 55 countries. The world-wide collection contains on the order of 17,202 species or varieties of fungi (including lichens and yeasts), 7,455 bacteria, 2,348 algae (including blue-green algae), 314 protozoa, 2,259 animal viruses, 500 bacterial viruses, 307 plant viruses and 68 insect viruses. A total of 646,555 strains representing 51,453 species and 4,058 genera are conserved, consisting of 397,136 bacteria, 254,169 fungi, 11,800 algae, 6,939 animal viruses, 3,433 bacterial viruses, 1,444 protozoa, 1,091 plant viruses, and 80 insect viruses. Agriculture, medicine, and industry all have benefited significantly from products derived from these cultures. Any of these cultures offer new sources of biosynthetic products, new sources of genes for hybridization, or even sources of characteristics for genetic engineering.
In addition to the basic functions of acquisition, authentication, preservation, and distribution of cultures and associated information, culture collections of microbial germplasm provide other services such as identification and taxonomic analyses of cultures, safe deposit of proprietary cultures, contract services, consulting services, information services, patent depositories, publications, sponsoring of workshops and training courses, and accommodation of visiting investigators. For interactions among existing culture collections, many organizations promote administrative and scientific coordination and information exchange between different collections, or between collections and appropriate scientific communities at the international, regional, and national level.