MICROBIAL DIVERSITY

The current list of the world's biodiversity is quite incomplete and that of viruses, microorganisms and invertebrates is especially deficient. The fungal diversity indicate the total number of species in a particular taxonomic group. The estimates of 1.5 million fungal species is based principally on a ratio of vascular plants of fungi of about 1:6.

Attempts to estimate total numbers of bacteria, archaea, and viruses even more problematical because of difficulties such as detection in and recovery from the environment,incomplete knowledge of obligate microbial associations. The microbial diversity, therefore appears in large
measure of reflect obligate or facultative associations with higher organisms and to be determined by the spatio-temporal diversity of their hosts or associates.

The perception of microbial diversity is being radically altered by DNA technique such as DNA-DNA hybridisation, nucleic acid fingerprinting and methods of assessing the outcome of DNA probing, and perhaps most important at present is 16S rRNA sequencing.

Biological diversity or biodiversity is actually evolved as a part of the evolution of organisms and the smallest unit of microbial diversity is a species. Bacteria due to lack of sexuality, fossil records etc., are defined as a group of similar strains distinguished sufficiently from other similar groups of strains by genotypic, phenotypic, and ecological characteristics.