Microbial products. IV. X-14847, a new aminoglycoside from Micromonospora echinospora.

Micromonospora echinospora strain X-14847 produces gentamicin A as the major antibiotic together with a new aminoglycoside, termed X-14847, and identified as a 2-amino-2-deoxy-alpha-D-glucopyranosyl myo-inositol. This report describes the taxonomy of the culture, fermentation conditions, the isolation and the identification of X-14847.

Three novel polyether antibiotics X-14889A, C, and D from a streptomycete. Taxonomy of the producing organism, fermentation production and biological properties of the antibiotics.

Antibiotic X-14889A, C, and D are novel polyether antibiotics related to lysocellin and antibiotic X-14873A. They are produced by a streptomycete isolated from a soil of Wisconsin. The antibiotic X-14889C is active against Gram-positive bacteria and exhibits ionophore property.

Antimetabolites produced by microorganisms. XV synthesis of 2-methyl-arginine, 2-methyl-l-ornithine and their enantiomers.

A new arginine antimetabolite was isolated from the fermentation broth of a new strain of Streptomyces and identified as 2-methyl-L-arginine.

Production of a novel red pigment, rubrolone, by Streptomyces echinoruber sp. nov. I. Taxonomy, fermentation and partial purification.

A taxonomic study of Streptomyces X-14077 (NRRL 8144), which produces a water-soluble purple-red pigment complex, revealed it to be a new species which has been named Streptomyces echinoruber sp. nov. The pigment complex was produced in deep culture fermentation and isolated by solvent extraction and concentration. The major pigment component, rubrolone, has low toxicity and may have potential as a food coloring agent. It appears to be devoid of antibiotic activity.

Microbial products. VIII. Azinothricin, a novel hexadepsipeptide antibiotic.

Azinothricin was isolated from the culture filtrate of Streptomyces sp. X-14950 in crystalline form. It represents a new type of hexadepsipeptide antibiotic as it contains a 19-membered cyclodepsipeptide ring composed of six unusual amino acids and bearing a novel C21 side chain. Azinothricin was identified as [(3S,4S,7R(S*),10S,17R,20S,23R)[2S(2'R*,5'S*, 6'S*)3S*]]-alpha-ethyl-6-(3-ethyl-1, 5-dimethyl-4-oxo-1,5-heptadienyl)- N-(1,8, 14,15,18,21,27-heptaaza-21-hydroxy-7-(1-hydroxyethyl)-2,6,9,16,19, 22-hexaoxo-4-isopropyl-20-(methoxy-methyl)-17,18-dimethyl-5-oxa tricyclo [21.4.0.0(10,15)]heptacosan-3-yl)tetrahydro-alpha, 2-dihydroxy-5-methyl-2H-pyran-2-acetamide and is primarily active against Gram-positive microorganisms.

X-14547A, a new ionophorous antibiotic produced by Streptomyces antibioticus NRRL 8167. Discovery, fermentation, biological properties and taxonomy of the producing culture.

X-14547A is a novel antibiotic produced by a new strain of Streptomyces antibioticus (NRRL 8167). The antibiotic is active in vitro against Gram-positive bacteria and is capable of complexing and transporting divalent as well as monovalent metal cations.

X-14885A, a novel divalent cation ionophore produced by a Streptomyces culture: discovery, fermentation, biological as well as ionophore properties and taxonomy of the producing culture.

Antibiotic X-14885A is a novel divalent cation ionophore produced by a Streptomyces culture isolated from soil sample collected in Wyoming. Its cation binding sequence has been found to be: Mg2+ greater than Ca2+, Sr2+ greater than Ba2+ much greater than Li+, Na+, Rb+, K+, Cs+.

Novel polyether antibiotics X-14873A, G and H produced by a Streptomyces: taxonomy of the producing culture, fermentation, biological and ionophorous properties of the antibiotics.

Novel polyether antibiotics X-14873A, X-14873G, and X-14873H are produced by the fermentation of Streptomyces sp. X-14873 (ATCC 31679). This report presents taxonomic studies and fermentation conditions for the antibiotic producing culture. The antibiotics are mainly active against Gram-positive bacteria. The ionophore properties of X-14873A are also characterized.

Chemotaxis in Actinoplanes.

The chemotactic properties of spores of Actinoplanes brasiliensis were examined. The spores are attracted to chloride and bromide solutions but not to a number of organic compounds that are capable of supporting growth in chemically defined media. Chloride attraction has been tested in several other species of the genus and in a number of Actinoplanes strains isolated from soils. Some are attracted to chloride, but most strains are indifferent to the halide. In dense suspensions, the spores of A. brasiliensis show an apparent microaerophilic behavior. The ecolotical implications of the chemotactic properties of the A. brasiliensis spores are discussed.

Chamber for bacterial chemotaxis experiments.

A design for a chemotaxis chamber and its use in bacterial chemotaxis experiments are described. Some of the advantages of the new design are discussed.

Prokaryotic diversity and the importance of culturing.

Modern approaches based on the use of molecular techniques presumed to circumvent the need for culturing prokaryotes, fail to provide sufficient and reliable information for estimation of prokaryote diversity. Many properties that make these organisms important members of the living world are amenable to observation only through the study of living cultures. Since current culture techniques do not always satisfy the need of providing a balanced picture of the microflora composition, future developments in the study of bacterial diversity should include improvements in the culture methods to approach as closely as possible the conditions of natural habitats. Molecular methods of microflora analysis have an important role as guides for the isolation and characterization of new prokaryotic taxa. Although the species concept is central to biodiversity studies, it is extremely difficult to propose a definition applicable without constraints to all groups of living organisms. However, in prokaryote systematics much improvement has been achieved by comprehensive descriptions that include not only molecular data, but also the relevant aspects of the biology of the organisms under study (polyphasic approach).

Pseudomonas classification. A new case history in the taxonomy of gram-negative bacteria.

Various criteria that have been used in the development of a system of classification of Pseudomonas species, as well as in the precise circumscription of the genus on phenotypic and molecular bases, are discussed. Pseudomonas taxonomy has transcended its own limits by suggesting a general strategy for the definition of taxonomic hierarchies at and above the genus level. A selection of studies on the biochemical and physiological properties of members of the genus is critically examined in relation to the current taxonomic scheme as a frame of reference.

Genetic recombination in Actinoplanes brasiliensis by protoplast fusion.

Protoplast formation, fusion, and cell regeneration have been achieved with mutant strains of Actinoplanes brasiliensis. Three-, four-, and five-factor crosses have shown genetic recombination among the markers, and a five-factor cross is analyzed and discussed. Possibilities of using protoplast fusion for gene mapping and strain improvement are suggested.

Stenotrophomonas, a new bacterial genus for Xanthomonas maltophilia (Hugh 1980) Swings et al. 1983.

In consideration of the criticisms of the transfer of Pseudomonas maltophilia to the genus Xanthomonas proposed by J. Swings, P. De Vos, M. Van den Mooter, and J. De Ley (Int. J. Syst. Bacteriol. 33:409-413, 1983), a new generic name is created for this taxon. The name Stenotrophomonas is here proposed for the new genus, which includes a single species, Stenotrophomonas maltophilia. This proposal restores the genus Xanthomonas to its former definition (J. Bradbury, p. 199-210, in N. R. Krieg and J. G. Holt, ed., Bergey's Manual of Systematic Bacteriology, 1984) The arguments on which this proposal is based are presented.

Taxonomic implications of synthesis of poly-beta-hydroxybutyrate and other poly-beta-hydroxyalkanoates by aerobic pseudomonads.

Whereas poly-beta-hydroxybutyrate (PHB) production by Pseudomonas species is rare, synthesis of medium-chain-length poly-beta-hydroxyalkanoates (mcl-PHAs) other than PHB, has been observed in fluorescent and non-fluorescent species. Contrary to original reports, Pseudomonas corrugata and Pseudomonas ficuserectae accumulate mcl-PHAs and not PHB. The taxonomic implications of these characteristics are discussed.

Phenotypic characterization and deoxyribonucleic acid homologies of Pseudomonas solanacearum.

Twenty-six strains and colony variants of Pseudomonas solanacearum belonging to four described biotypes were characterized, by using 169 phenotypic characters previously found useful in distinguishing among strains of other Pseudomonas species. Deoxyribonucleic acid (DNA) hybridization (intra- and interspecific DNA-DNA hybridizations) was performed by using the in vitro "DNA competition" technique. P. solanacearum appears to be a moderately homogeneous species, which is, at most, only remotely related to all other species of the genus studied to date. The four biotypes are not clearly distinct from one another with respect to nutritional characters or DNA homologies. Discrepancies between acid production and growth with some carbohydrates were noted. Difficulties were encountered in certain DNA competition experiments and some problems of the methodology are discussed.