ABSTRACT
Alkaliphilic microorganisms have many industrial applications. Many of them produce compounds of industrial interest and also they possess useful physiological properties which can facilitate their exploitation for commercial purposes. In the realm of antibiotic world, opening of the field of antibiotics from actinomycetes was marked by isolation of actinomycin. Natural and manmade water bodies including geothermal vents and natural meteorite crater lakes, thermal springs are well known habitats of thermophilic actinomycetes. The rapid growth rates of actinomycetes at elevated temperatures necessitate a shorter incubation period as compared to mesophilic actinomycetes. Antimicrobial producing genes are tightly clustered in the microbial chromosomes, both gene replacement and coregulation of all the genes necessary for antibiotic formation are facilitated. The thermophilic bacteria and actinomycetes have been less explored due to difficulties in isolation and maintenance in pure culture. Thermophilic bacteria and actinomycetes were described almost simultaneously towards the end of the nineteenth century and have been the subject of several historical reviews.
