Streptomyces: A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.Streptomyces griseus: An actinomycete from which the antibiotics STREPTOMYCIN, grisein, and CANDICIDIN are obtained.Streptomyces coelicolor: A soil-dwelling actinomycete with a complex lifecycle involving mycelial growth and spore formation. It is involved in the production of a number of medically important ANTIBIOTICS.Streptomyces lividans: An actinomycete used for production of commercial ANTIBIOTICS and as a host for gene cloning.Streptomyces antibioticus: An actinomycete from which the antibiotic OLEANDOMYCIN is obtained.Streptomyces aureofaciens: An actinomycete from which the antibiotic CHLORTETRACYCLINE is obtained.Anthraquinones: Compounds based on ANTHRACENES which contain two KETONES in any position. Substitutions can be in any position except on the ketone groups.Fermentation: Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Bacterial Proteins: Proteins found in any species of bacterium.Genes, Bacterial: The functional hereditary units of BACTERIA.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Naphthacenes: Polyacenes with four ortho-fused benzene rings in a straight linear arrangement. This group is best known for the subclass called TETRACYCLINES.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Prodigiosin: 4-Methoxy-5-((5-methyl-4-pentyl-2H-pyrrol-2-ylidene)methyl)- 2,2'-bi-1H-pyrrole. A toxic, bright red tripyrrole pigment from Serratia marcescens and others. It has antibacterial, anticoccidial, antimalarial, and antifungal activities, but is used mainly as a biochemical tool.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Soil Microbiology: The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.Streptomycetaceae: A family of soil bacteria. It also includes some parasitic forms.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Macrolides: A group of often glycosylated macrocyclic compounds formed by chain extension of multiple PROPIONATES cyclized into a large (typically 12, 14, or 16)-membered lactone. Macrolides belong to the POLYKETIDES class of natural products, and many members exhibit ANTIBIOTIC properties.Spores, Bacterial: Heat and stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria of the genera Bacillus and Clostridium.4-Butyrolactone: One of the FURANS with a carbonyl thereby forming a cyclic lactone. It is an endogenous compound made from gamma-aminobutyrate and is the precursor of gamma-hydroxybutyrate. It is also used as a pharmacological agent and solvent.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Tylosin: Macrolide antibiotic obtained from cultures of Streptomyces fradiae. The drug is effective against many microorganisms in animals but not in humans.Antibiotics, Antineoplastic: Chemical substances, produced by microorganisms, inhibiting or preventing the proliferation of neoplasms.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Leucomycins: An antibiotic complex produced by Streptomyces kitasatoensis. The complex consists of a mixture of at least eight biologically active components, A1 and A3 to A9. Leucomycins have both antibacterial and antimycoplasmal activities.Cephamycins: Naturally occurring family of beta-lactam cephalosporin-type antibiotics having a 7-methoxy group and possessing marked resistance to the action of beta-lactamases from gram-positive and gram-negative organisms.Aminoglycosides: Glycosylated compounds in which there is an amino substituent on the glycoside. Some of them are clinically important ANTIBIOTICS.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Candicidin: Mixture of antifungal heptaene macrolides from Streptomyces griseus or Actinomyces levoris used topically in candidiasis. The antibiotic complex is composed of candicidins A, B, C, and D, of which D is the major component.Chemistry: A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.Chemical Phenomena: The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Naphthoquinones: Naphthalene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.Biosynthetic Pathways: Sets of enzymatic reactions occurring in organisms and that form biochemicals by making new covalent bonds.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Open Reading Frames: A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).Actinobacteria: Class of BACTERIA with diverse morphological properties. Strains of Actinobacteria show greater than 80% 16S rDNA/rRNA sequence similarity among each other and also the presence of certain signature nucleotides. (Stackebrandt E. et al, Int. J. Syst. Bacteriol. (1997) 47:479-491)Physicochemical Phenomena: The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.Polyketide Synthases: Large enzyme complexes composed of a number of component enzymes that are found in STREPTOMYCES which biosynthesize MACROLIDES and other polyketides.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Chemistry, Physical: The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Actinomycetales: An order of gram-positive, primarily aerobic BACTERIA that tend to form branching filaments.ChitinaseDNA, Ribosomal: DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.Spiramycin: A macrolide antibiotic produced by Streptomyces ambofaciens. The drug is effective against gram-positive aerobic pathogens, N. gonorrhoeae, and staphylococci. It is used to treat infections caused by bacteria and Toxoplasma gondii.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Polyenes: Hydrocarbons with more than one double bond. They are a reduced form of POLYYNES.Chromomycins: A complex of several closely related glycosidic antibiotics from Streptomyces griseus. The major component, CHROMOMYCIN A3, is used as a fluorescent stain of DNA where it attaches and inhibits RNA synthesis. It is also used as an antineoplastic agent, especially for solid tumors.Oleandomycin: Antibiotic macrolide produced by Streptomyces antibioticus.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Streptomycin: An antibiotic produced by the soil actinomycete Streptomyces griseus. It acts by inhibiting the initiation and elongation processes during protein synthesis.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Ivermectin: A mixture of mostly avermectin H2B1a (RN 71827-03-7) with some avermectin H2B1b (RN 70209-81-3), which are macrolides from STREPTOMYCES avermitilis. It binds glutamate-gated chloride channel to cause increased permeability and hyperpolarization of nerve and muscle cells. It also interacts with other CHLORIDE CHANNELS. It is a broad spectrum antiparasitic that is active against microfilariae of ONCHOCERCA VOLVULUS but not the adult form.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Thiostrepton: One of the CYCLIC PEPTIDES from Streptomyces that is active against gram-positive bacteria. In veterinary medicine, it has been used in mastitis caused by gram-negative organisms and in dermatologic disorders.Lactones: Cyclic esters of hydroxy carboxylic acids, containing a 1-oxacycloalkan-2-one structure. Large cyclic lactones of over a dozen atoms are MACROLIDES.Transformation, Bacterial: The heritable modification of the properties of a competent bacterium by naked DNA from another source. The uptake of naked DNA is a naturally occuring phenomenon in some bacteria. It is often used as a GENE TRANSFER TECHNIQUE.Streptothricins: A group of antibiotic aminoglycosides differing only in the number of repeating residues in the peptide side chain. They are produced by Streptomyces and Actinomyces and may have broad spectrum antimicrobial and some antiviral properties.Drug Resistance, Microbial: The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).Xylan Endo-1,3-beta-Xylosidase: A xylosidase that catalyses the random hydrolysis of 1,3-beta-D-xylosidic linkages in 1,3-beta-D-xylans.Clavulanic Acid: Clavulanic acid and its salts and esters. The acid is a suicide inhibitor of bacterial beta-lactamase enzymes from Streptomyces clavuligerus. Administered alone, it has only weak antibacterial activity against most organisms, but given in combination with other beta-lactam antibiotics it prevents antibiotic inactivation by microbial lactamase.Oxytetracycline: A TETRACYCLINE analog isolated from the actinomycete STREPTOMYCES rimosus and used in a wide variety of clinical conditions.Lactams: Cyclic AMIDES formed from aminocarboxylic acids by the elimination of water. Lactims are the enol forms of lactams.