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M ALEXANDER

Publications and source records attributed to M ALEXANDER.

At least 19 recordsLinked to original sources
PubMed1965

NODULATION FACTOR FOR RHIZOBIUM-LEGUME SYMBIOSIS.

Valera, Concepcion L. (Cornell University, Ithaca, N.Y.), and M. Alexander. Nodulation factor for Rhizobium-legume symbiosis. J. Bacteriol. 89:1134-1139. 1965.-Nodulation of excised roots of Medicago sativa was enhanced by an extract of alfalfa seeds but not by several other substances. Coconut water exerted a similar influence upon the formation of nodules on excised roots of Glycine max and Phaseolus vulgaris. Direct evidence for a host factor concerned in nodule genesis was obtained by demonstrating that, although P. vulgaris seedlings developing from embryos devoid of cotyledons nodulated in the presence of an infective Rhizobium strain, nodules did not appear on explants derived from hypocotyls obtained from ungerminated seed. The legume factor, when examined by a soybean hypocotyl bioassay procedure, could be replaced by a water-soluble, thermostable, dialyzable fraction of coconut water, but not by meso-inositol, scyllitol, sorbitol, yeast extract, or a number of amino acids.

Fabaceae↗
PubMed1964

ANAEROBIC GROWTH OF FUSARIUM OXYSPORUM.

Gunner, H. B. (Cornell University, Ithaca, N.Y.), and M. Alexander. Anaerobic growth of Fusarium oxysporum. J. Bacteriol. 87:1309-1316. 1964.-Fusarium oxysporum, an alleged obligate aerobe, was found to be capable of growth in the absence of molecular oxygen, provided the medium contained yeast extract, MnO(2), nitrate, selenite, or ferric ions. The active substance in yeast extract was not identified. The fungus possessed hydrogenase, and was capable of utilizing H(2). Under anaerobic conditions, the fungus effected the reduction of nitrate, ceric, ferric, selenite, and tellurite ions, as well as the reduction of several inorganic sulfur compounds and indicators having positive oxidation-reduction potentials. The products of anaerobic nitrate-dependent growth were ethanol, CO(2), acetic acid, and ammonia. Possible explanations for the apparent inability of obligate aerobes to grow in the absence of O(2) are discussed.

Ammonia↗
PubMed1963

METABOLISM OF PHENOXYALKYL CARBOXYLIC ACIDS BY A FLAVOBACTERIUM SPECIES.

Macrae, I. C. (Cornell University, Ithaca, N.Y.), and M. Alexander. Metabolism of phenoxyalkyl carboxylic acids by a Flavobacterium species. J. Bacteriol. 86:1231-1235. 1963.-A Flavobacterium sp. isolated from soil and grown in media containing 4-(2,4-dichlorophenoxy) butyric acid metabolized omega-linked 2,4-dichlorophenoxyalkyl carboxylic acids in the series from 3-(2,4-dichlorophenoxy)propionic acid through 11-(2,4-dichlorophenoxy)undecanoic acid rapidly and without a preliminary induction phase. There was no detectable oxidation of 2,4-dichlorophenoxyacetic acid. Phenols and the fatty acids corresponding to the aliphatic side chains were liberated during the decomposition of the dichlorophenoxy alkanoates from propionate to octanoate. The data indicate that the initial step in the degradation of omega-linked 2,4-dichlorophenoxyalkyl carboxylic acids by the bacterium involves a cleavage of the ether linkage, a new mechanism for the microbial metabolism of these compounds.

Bacteria↗