Diaminopimelic acid profiles of alkalophilic and alkaline-resistant strains of Actinomycetes.

Twenty alkalophilic actinomycetes with optimum growth pH of 9.0 to 9.5 were isolated. Although these new isolates morphologically closely resembled conventional streptomycetes containing LL-diaminopimelic acid, nine out of 20 isolated contained meso-diaminopimelic acid. Among 420 International Streptomyces Project (ISP) Streptomyces strains tested for their maximum growth pH, only 6 strains grew at pH 11.5. Of these six strains, three strains, S. caeruleus ISP 5103, A. alborubidus ISP 5465 and S. autotrophicus ISP 5011 contained meso-diaminopimelic acid.