Anovel antibiotic, GE2270A, was isolated from the fermentation broth of a strain of Planobispora rosea. The product was found to inhibit bacterial protein synthesis. Structural characteristics showed similarities between GE2270 A and thiazolyl peptides such as micrococcin which is known to inhibit protein synthesis by acting directly on the ribosome. Despite this similarity GE2270A showed functional analogy to kirromycin-like antibiotics and pulvomycin, as its molecular target was found to be elongation factor Tu (EF-Tu). GE2270A is active against Gram-positive microorganism and anaerobes and differs from the other EF-Tu inhibitors in its spectrum of antimicrobial activity. 693 GE2270A, a novel peptide antibiotic, emerged from a screening program designed to detect inhibitors of protein synthesis. The present paper deals with the discovery, isolation, initial physico-chemical and biological characterization of this antibiotic. Materials and Methods Cultural and Growth Characteristics of the Producing Strain Colonial and morphological characters were determined with standard methods1'2*. Color determination was madeaccording to Maerz and Paul3). Growthon sole sources of carbon was determined after incubation at 28°C for 2 weeks1*. Chemotaxonomic Characteristics of the Producing Strain Freeze-dried biomass was examined to determine the major chemotaxonomiccharacteristics. Cell wall diamino acids were determined by TLCby a modification of the method of Becker et a/.4)5). Wholecell sugars were hydrolyzed, reduced and derivatized. The resultant alditol acetates were analyzed by GC6). Fatty acid methyl esters were similarly analyzed by GC7). Menaquinones and polar lipids were extracted and analyzed by HPLCand 2D TLC, respectively8*. Fermentation of the Producing Strain A 500-ml Erlenmeyer flask containing 100 ml of seed medium (Pdlypeptone 0.5%, yeast extract 0.3%, beef extract 0.2%, soybean meal 0.2%, starch 2%, calcium carbonate 1%, pH 7.0) was inoculated from an oatmeal slant of the producing strain. After incubation at 28°C for 96 hours on a rotary shaker (200 rpm), the biomass was transferred to a 10-liter jar fermenter containing 4 liters of the seed medium. This culture was grown for 72 hours at 28°C with 2 liters/minute air flow and stirring at 900rpm, prior to inoculating a jar fermenter containing 50 liters of production medium(starch 2%, peptone 0.25%,

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We have isolated and sequenced partial cDNA clones that encode SO‐6, a ribosome‐inactivating protein from Saponaria officinalis. A cDNA library was constructed from the leaves of this plant and screened with synthetic oligonucleotide probes representing various portions of the protein. The deduced amino acid sequence shows the signal peptide and a coding region virtually accounting for the entire amino acid sequence of SO‐6. The sequence reveals regions of similarity to other ribosome‐inactivating proteins, especially in a region of the molecule where critical amino acid residues might participate in the active site.

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Llbrarv of Congres• Cataloglng-ln-Publlcatlon DataLanc1n1, G1ancarlo.B1otechnology of ant1b1ot1cs and other b1oact1ve N1crob1al metabo11tes 1 G1ancarlo Lanc1n1 and Rolando Lorenzett1. PrefaceAntibiotics are the most prescribed drugs in human medicine. Almost every one of us will receive an antibiotic at some time in our lives for an infectious disease. As antimicrobial agents, antibiotics are also widely used in agriculture, animal husbandry, and the food industry. Several of the most efficacious antitumor agents are also antibiotics. Other microbial secondary metabolites are becoming more and more important for their pharmacological properties or as pesticide agents. Studies of secondary metabolite biochemistry and genetics are greatly contributing to our understanding of microbial evolution and differentiation. The search for novel secondary metabolites, the development of the producing strains, and the improvement of industrial production involve several disciplines, such as basic and applied microbiology, microbial biochemistry and genetics, and molecular biology.The aim ofthis book is to give up-to-date, concise information on these aspects, which we now refer to as biotechnology. The book has been conceived as a teaching aid for advanced undergraduate and graduate students, but I believe it may also provide useful background on this subject to junior staff members of research and industrial laboratories.The major problem we encountered in writing the book was selecting, from the enormous literature, the most relevant material so as to make the book both informative and readable. Rather than providing long lists of products and tables, more suitable for review articles and treatises, we have chosen to use examples that could help the reader understand the progress made in the different disciplines. The references, v vi PREFACE listed at the end of each chapter, should help the reader who needs additional information.My co-author, Rolando Lorenzetti, and I wish to express our thanks to our colleagues who reviewed the different chapters, and in particular to Dr. William Higgins, who provided useful criticisms and comments, and to Ms. Karen Hutchinson Parlett, who patiently revised the English style.