Bio-Fertilizers are natural fertilizers which are microbial inoculants of bacteria, algae, fungi alone or in combination and they augment the availability of nutrients to the plants. These broadly include the nitrogen fixers (symbiotic & nonsymbiotic bacteria), phosphate solubilizing fungi and bacteria & the mycorrhizal fungi that are capable of mobilizing nonlabile nutrients from soil & transporting them to & across plant roots. So far, emphasis has been given only to certain types of biofertilizers, such as Rhizobium, Azotobacter, Azospirillum and Phosphate solubilizing bacteria (PSB). Usually carrier materials, such as peat, lignite, peat soil, humus, wood charcoal or similar material favoring the growth of microorganisms is used. However, in practice a large variety of microbial inoculants are available and being used as biofertilizers. These include Azolla, Trichoderma, Frankia and Vesicular Arbuscular Mycorrhiza (VAM). A point to consider before using biofertilisers produced by commercial units is the issue of using microorganisms native to another area or region. It is possible to isolate the required species of microorganisms from a farm's soil and mass produce them. Besides allowing a better chance of survival of the organism(s) used, this ensures that local species of microorganisms alone are used. There are a few crude (but fairly effective), as well as standard laboratory procedures for isolation and mass production of biofertilisers.