Abstract
Streptomyes tendae Tü 901/8c produces several secondary metabolites originating from different biosynthetic pathways, namely the nikkomycins, ketomycin, chlorothricin and the juglomycins. The significance of the stringent response in the induction of the nikkomycin production during different growth rates in continuous culture and batch fermentations was investigated. Merely, after nutritional shift down into chemically defined medium the strain exhibited a stringent response with two accompanying intracellular accumulations of ppGpp. This was found to be due to different consumption rates of some intracellular amino acids and dependent on relA functions. A relaxed mutant with a reduced ability to accumulate ppGpp, also with respect to the second accumulation observed, failed to produce nikkomycins.
