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H A Lechevalier

Publications and source records attributed to H A Lechevalier.

At least 19 recordsLinked to original sources
PubMed1989

LL-E19020 alpha and beta, animal growth promoting antibiotics: taxonomy, fermentation and biological activity.

Antibacterial antibiotics LL-E19020 alpha and beta were isolated from the fermentation broth of an actinomycete strain. Based on cultural and physiological characteristics, culture LL-E19020 was identified as a new subspecies of Streptomyces lydicus. The LL-E19020 alpha and beta antibiotics were found to possess a very narrow antibacterial spectrum against human pathogens. In studies in chickens, LL-E19020 alpha demonstrated excellent growth promoting activity.

Aminoglycosides↗
PubMed1989

LL-E19085 alpha, a novel antibiotic from Micromonospora citrea: taxonomy, fermentation and biological activity.

A new antibacterial antibiotic, designated LL-E19085 alpha, was isolated from the fermentation broth of an actinomycete strain. Based on cultural, physiological, morphological and chemical characteristics, culture LL-E19085 was identified as a new subspecies of Micromonospora citrea. Antibiotic LL-E19085 alpha demonstrated potent activity against a spectrum of Gram-positive aerobic and anaerobic bacteria.

Animals↗
PubMed1980

Structures and antimicrobial activity of peniophorin A and B, two polyacetylenic antibiotics from Peniophora affinis Burt.

Two polyacetylenic antibiotics, peniophorin A and B, have been isolated from a strain of Peniophora affinis. Both have antibacterial and antifungal activity, but B is 3 to 20 times more active than A. Gram-positive cocci and a strain of Proteus vulgaris were especially susceptible to these two antibiotics. Both peniophorins contained an aromatic ring; B was an acid, and A was neutral. Peniophorin B was shown to be 2-(1-oxo-2,4-pentadiynl)phenyl acetic acid. The structure of A was only partially elucidated; it is suspected to be 6-[2-(1-oxo-2,4-pentadiynl)phenyl]5-methoxy-3-oxo-4-hexene-1-ol.

Alkynes↗
PubMed1970

Motile nocardoid Actinomycetales.

The properties of 42 strains of nocardoid (nocardioform) bacteria were compared. The results indicate that the organism previously called Nocardia turbata does not belong to the genus Nocardia nor does it fit into any of the previously described genera.

Actinomycetales↗
PubMed1967

Chemical composition of variants of aerobic actinomycetes.

It has been shown previously that aerobic actinomycetes can be separated into four main groups on the basis of their cell wall composition. Six representatives of aerobic actinomycetes (Nocardia asteroides and Micropolyspora brevicatena, cell wall type IV; N. madurae, Microbispora rosea, cell wall type III; Actinoplanes sp., cell wall type II; Streptomyces griseus, cell wall type I) were subjected to selecting agents which permitted the isolation of stable variants morphologically different from the parent strain. Whole cell analyses of 134 substrains from the six parents revealed no significant change in the isomeric form of diaminopimelic acid or in sugar constituents. Analyses of cell wall preparations from 52 of these did not reveal any change in the diagnostic constituents of their murein or polysaccharides.

Journal Article↗
PubMed1967

Flagellated actinomycetes.

Shadowed motile elements from actinomycetes were observed with an electron microscope. Included were three strains of Actinoplanes, two of Ampullariella, two of Dermatophilus, two of Spirillospora, and four of "Nocardia" turbata. In addition, three types of previously undescribed actionmycetes were represented: (i) the C(4) group (four strains) forming substrate mycelium breaking into motile rods; (ii) strain 9-41, forming Microellobosporia-like sporangia with motile spores; and (iii) strain P(2), forming aerial hyphae releasing motile cocci when put in water. All the known chemical cell wall types of actinomycetes except the Nocardia asteroides type and the Actinomyces israeli type were represented in this array of motile actinomycetes. Motile elements were, depending on the genus, cocci, rods (often curved), or pyriform. Flagella were always in tufts (or single), never peritrichous. A relationship seems to exist between the location of the tuft and the cell wall composition. The spores of one strain of Actinoplanes were herniated, thus resembling plasmoptysis forms of bacteria.

Actinomycetales↗
PubMed1966

Electron microscopic observation of the sporangial structure of strains of Actinoplanaceae.

Lechevalier, Hubert A. (Rutgers, The State University, New Brunswick, N.J.), Mary P. Lechevalier, and Pauline E. Holbert. Electron microscopic observation of the sporangial structure of strains of Actinoplanaceae. J. Bacteriol. 92:1228-1235. 1966.-Eight strains of Streptosporangium spp. and one strain each of Spirillospora albida and an Ampullariella-like Actinoplanes sp. were observed by electron microscopy. The sporangiospores of all these organisms had a smooth surface. All formed their sporangia by the ingrowth of a hypha inside a bag formed by the extension of the outer sheath of the sporangiophore. The sporogenic hypha was not branched in strains of Streptosporangium but was branched in S. albida and the Actinoplanes sp. Spore formation was by septation of the intrasporangial hyphae. When it occurred, septation took place by the same annular ingrowth of the cell wall common in gram-positive bacteria. The septum at the apex of the sporangiophore was formed before the others. Septation was seen to occur between two fully formed septa, indicating almost simultaneous formation of large segments dividing again, almost simultaneously, into smaller spore-sized segments.

Actinomycetales↗
PubMed1965

Geosmin, an earthly-smelling substance isolated from actinomycetes.

Geosmin, an earthy-smelling substance, has been isolated from several actinomycetes. Production of 1 mg per liter of whole broth was obtained from Streptomyces griseus LP-16. After preliminary separations, pure geosmin was isolated in milligram amounts by gas chromatography. Geosmin is a neutral oil, with an approximate boiling point of 270 C, which contains carbon and hydrogen, but no nitrogen. It undergoes a reaction with acid to give odorless argosmin, a neutral oil, with an approximate boiling point of 230 C, which contains only carbon and hydrogen. Specific rotation and ultraviolet- and infrared-absorbtion spectra were determined for both.

Chemical Phenomena↗
PubMed1965

Candicidin and other polyenic antifungal antibiotics.

About 50 polyenic antifungal antibiotics produced by actinomycetes have been isolated and described. Among these are the most effective antimonilial agents so far known. These polyenes can be classified into four broad groups depending on the number of conjugated carbon-to-carbon double bonds that are present in their chromophores. Only some of the tetraenes (four conjugated double bonds), such as nystatin and pimaricin, and a few heptaenes (seven conjugated double bonds), such as amphotericin B, Trichomycin candicidin and hamycin, have found practical application in the treatment of infectious diseases caused by fungi. Nystatin and pimaricin show the least in vitro activity against fungi, while trichomycin and candicidin are the most active. Recent clinical investigations carried out in the USA have shown that candicidin is very effective in the treatment of vaginal monilial infections.

Antifungal Agents↗