Actinomycetes are best known for their ability to produce antibiotics. These special metabolites, in contrast to the general nature of primary metabolites, are produced only by some species of a genus, and by some strains of a species. Nutrient deficiency in nature often induces chemical differentiation, i.e. secondary metabolism which is beneficial for survival in the wild. Basic Local Alignment Search Tool allows rapid sequence comparison of query sequence against a database and hence can be used to infer functional and evolutionary relationships between sequence as well as help identify members of gene families. This monograph has detail protocols that can be used for SCREENING & IDENTIFICATION OF ACTINOMYCETES PRODUCING SECONDARY METABOLITES AGAINST GRAM NEGATIVE BACTERIA UNDER NUTRIENT DEFICIENT CONDITIONS.