A new antibacterial antibiotic, designated simaomicin a (LL-D42067a) was isolated from the fermentation broth of an actinomycete strain. Based on cultural, physiological, morphological and chemical characteristics, culture LL-D42067was identified as a newsubspecies of Actinomadura madurae. Simaomicin a demonstrated potent activity against Gram-positive bacteria and was active in vivo against a variety of Eimeria species causing coccidiosis in chickens.

A new antibacterial antibiotic, designated LL-E19085a:, was isolated from the fermentation broth of an actinomycete strain. Based on cultural, physiological, morphological and chemical characteristics, culture LL-E19085was identified as a new subspecies of Micromonospora citrea. Antibiotic LL-E19085ademonstrated potent activity against a spectrum of Gram-positive aerobic and anaerobic bacteria.

A novel family of antitumor antibiotics, designated LL-D49194, was isolated from the fermentation broth of an actinomycete strain identified as Streptomyces vinaceus-drappus. LL-D49194 a1 and p2 were active against Gram-positive and inactive against Gram-negative bacteria in vitro. The p± component was not active against either Gram-positive or Gram-negative bacteria. These antibiotics exhibited significant in vivo activities against several murine tumors, albeit with differing potencies.In the course of our search for novel antitumor agents produced by microorganisms, a culture designated LL-D49194was isolated from a soil sample and was found to produce a new family of antitumor compounds (Fig. 1). This paper describes the taxonomy of the producing culture, fermentation and biological activities of these agents. Materials and Methods MicroorganismCulture LL-D49194 was isolated from a soil sample collected in La Encanada, Peru. This culture was Fig. 1. Chemical structures of LL-D49194 al5 px and f}2.

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Antibacterial antibiotics LL-E19020a and p were isolated from the fermentation broth of an actinomycete strain. Based on cultural and physiological characteristics, culture LL-E19020was identified as a new subspecies of Streptomyces lydicus. The LL-E19020aand f$ antibiotics were found to possess a very narrowantibacterial spectrumagainst humanpathogens. In studies in chickens, LL-E19020a demonstrated excellent growth promoting activity. In the course of our search for novel antibacterial antibiotics produced by microorganisms, a culture designated LL-E19020 was found to produce antibiotics, LL-E19020a and p. These antibiotics possessed a very narrow antibacterial spectrum against human pathogens. This paper describes the taxonomy of the producing culture, fermentation and biological activity of LL-E19020a and p.