Microorganisms from extreme environments have gained
considerable attention in recent years. This is mainly due to
the fact that they hold about the molecular evolution of life
and stability of themacromolecules. Majority of the studies on
extremophilic organisms, however, have been confined to
extremophilic bacteria and actinomycetes are relatively less
explored group. A novel, alkaliphilic actinomycetes Nocardiopsis
alkaliphila sp. nov.was reported [33] to grow optimally at
pH9.5—10. N.metallicus [25] exhibited growth in the pHrange
7—10.5, whereas in Bogoriella caseilytica [13], a new alkaliphilic
actinomycete, optimum growth occurred at pH values
9—10. It is widely accepted that alkaliphilic actinomyceteswill
provide a valuable resource for novel products of industrial
interest, including enzymes and antimicrobial agents [18].
Pyrocoll, an antibiotic, antiparasitic and antitumor compound
was recently detected in novel alkaliphilic Streptomyces
strain [5]. Moreover, few marine actinomycetes have also
been recently reported for their antimicrobial activity [7].
Some novel antitumour antibiotics, such as chinikomycin and
lajollamycin were detected in marine Streptomyces spp.
[15,17]. These recent examples from the literature highlights
the fact that despite extensive exploration of the actinomycetes
for their antimicrobial products in the past, the search
for novel molecules having unique therapeutic properties
continues to be an active area of research. In the course of
screening for new antibiotics, several studies are oriented
towards isolation of new Streptomyces species from different
habitats. The list of novel actinomycetes and products derived
from poorly explored areas of the world, stresses the importance
of investigating new habitats [19]. Investigation on the
biosynthesis of antibiotic involves an optimization of culture
media for their production that can be achieved by a systematic
study of the suitability of physiological parameters and
supplementary nutrition. Cultural parameters and medium
constituents are the important factors influencing antimicrobial
agent production