Two unusual budding bacteria isolated from a swimming pool

S ly , L.I. & H argreaves , M.H. 1984. Two unusual budding bacteria isolated from a swimming pool. Journal of Applied Bacteriology 56 , 479–486.
Two unusual strains of budding bacteria were isolated on a Millipore Pseudomonas Count Water Tester during routine monitoring of Pseudomonas aeruginosa counts in a swimming pool. The first isolate has been identified as Blastobacter sp. It was a yellow-pigmented, Gram negative rod-shaped organism with a polar holdfast by which it attached to solid surfaces or other cells to form rosettes. The cells reproduced by asymmetric division or budding at the free pole of the cell, producing motile daughter cells with a single polar flagellum. The second isolate, which has not yet been identified, was a red-pigmented, Gram negative rod-shaped organism which produced one or more buds at each pole of the cell. Cell division appears to occur by both binary fission and by budding. Both organisms were strict aerobes, catalase and oxidase positive and did not produce acid from glucose in Hugh and Leifson medium.     

Preservation of Rhizobium viability and symbiotic infectivity by suspension in water

Three Rhizobium japonicum strains and two slow-growing cowpea-type Rhizobium strains were found to remain viable and able to rapidly modulate their respective hosts after being stored in purified water at ambient temperatures for periods of 1 year and longer. Three fast-growing Rhizobium species did not remain viable under the same water storage conditions. After dilution of slow-growing Rhizobium strains with water to 10(3) to 10(5) cells ml-1, the bacteria multiplied until the viable cell count reached levels of between 10(6) and 10(7) cells ml-1. The viable cell count subsequently remained fairly constant. When the rhizobia were diluted to 10(7) cells ml-1, they did not multiply, but full viability was maintained. If the rhizobia were washed and suspended at 10(9) cells ml-1, viability slowly declined to 10(7) cells ml-1 during 9 months of storage. Scanning electron microscopy showed that no major morphological changes took place during storage. Preservation of slow-growing rhizobia in water suspensions could provide a simple and inexpensive alternative to current methods for the preservation of rhizobia for legume inoculation.     

Biotechnology and agricultural improvement

A range of emerging technologies are expected to play a significant role in agricultural improvement in the next 20 years. Some are only now being explored, but others have already produced significant results. Recent progress in the tissue culture and genetic engineering of crop plants has opened the door to: (1) large scale and rapid propagation of genetically uniform plants from elite materials; (2) the selection of novel and improved varieties using somaclonal variation technology; (3) the development of new hybrids between different cultivars and species by means of protoplast fusion and (4) the use of recombinant DNA to introduce new genetic material into plant cells. It is expected that, by the year 2000, a wide range of crops will be affected by these advances in biotechnology.     

Biological activities of isomers of 8, 15-dihydroxyeicosatetraenoic acid

Chemically synthesized 8(S)-dihydroxy-5, 11-cis-9, 13-transeicosatetraenoic acid and 8(R), 15(S)-dihydroxy-5, 11-cis-9, 13-transeicosatetraenoic acid were inactive, in comparison to leukotriene B₄, in a human polymorphonuclear leukocyte chemokinetic assay and a rat polymorphonuclear leukocyte aggregation assay.     

The role of the secondary plant compound 2,5-dihydroxymethyl 3,4-dihydroxypyrrolidine as a feeding inhibitor for insects

The cyclic amino alditol 2,5-dihydroxymethyl 3,4-dihydroxypyrrolidine (DMDP) has recently been shown to be an inhibitor of various glucosidases. We have investigated its role as a plant protective chemical against a range of phytophagous insects by examining its effects on development, feeding behaviour and functioning of taste receptors. We have shown that it can inhibit feeding and can be toxic. The mechanisms by which these effects are achieved are discussed in the context of the molecular structure of the compound.

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Résumé Récemment a été mis en évidence le puissant pouvoir inhibiteur de différents glucosidases. Présenté par l'amino-alditol cyclique, 2,5 dihydroxymethyl 3,4 dihydroxypyrrolidine (DMDP), isolé de graines de la légumineuse Lonchocarpus sericeus. Nous avons examiné le rôle de ce composé secondaire dans la stratégie défensive de la plante contre une gamme d'insectes phytophages, à travers son action sur le développement, le comportement alimentaire et le fonctionnement des récepteurs gustatifs. Nous avons montré que DMDP peut inhiber, suivant la dose, la prise de nourriture et, qu'aprs ingestion (par Spodoptera spp), il peut agir comme une toxine. Par suite de sa structure moléculaire, DMDP peut être considéré, non seulement comme l'analogue d'un sucre, mais aussi comme un alcaloïde. Le bilan des résultats de nos expériences suggère que l'efficacité de DMDP comme phagodissuadant, si elle ne provient pas de sa toxicité, découle principalement de ses propriétés d'alcaloïde.

     

Inhibition of polar calcium movement and gravitropism in roots treated with auxin-transport inhibitors

Primary roots of maize (Zea mays L.) and pea (Pisum sativum L.) exhibit strong positive gravitropism. In both species, gravistimulation induces polar movement of calcium across the root tip from the upper side to the lower side. Roots of onion (Allium cepa L.) are not responsive to gravity and gravistimulation induces little or no polar movement of calcium across the root tip. Treatment of maize or pea roots with inhibitors of auxin transport (morphactin, naphthylphthalamic acid, 2,3,5-triiodobenzoic acid) prevents both gravitropism and gravity-induced polar movement of calcium across the root tip. The results indicate that calcium movement and auxin movement are closely linked in roots and that gravity-induced redistribution of calcium across the root cap may play an important role in the development of gravitropic curvature.Abbreviations 9-HFCA 9-hydroxyfluorenecarboxylic acid - NPA naphthylphthalamic acid - TIBA 2,3,5-triiodobenzoic acid - IAA indole-3-acetic acid     

Discrimination by male ring-tailed Lemurs (Lemur catta) between the scent marks of male and those of female conspecifics

Olfaction plays an important role in the social communication of all prosimians. (The experiment reported in this paper forms part of an intensive chemobehavioral study of olfaction in Lemur catta (ring-tailed lemur) being carried out in this laboratory.) Five male Lemur cattawere tested on their behavioral responses to paired scent stimuli. Responses measured were (1) total investigation time, (2) arm-marking, (3) ABO/BO rubbing, and (4) flehmen. Males showed a strong discrimination between the scent stimuli,giving higher levels of response to female scent on measures 1, 3, and 4. This response suggests an olfactory-related preference by males for female scent under controlled conditions. This preference may be a consequence of the females’ dominance over males and the brevity of estrus in L. catta,both of which would favor such choice behavior.     

Mechanism of natural delayed-type hypersensitivity reactions to tumor cells in nonimmunized syngeneic guinea pigs

Summary Nonimmunized 2/N guinea pigs respond to the presence of chemical carcinogen-transformed syngeneic tumorigenic cells with a sustained (delayed-hypersensitivity-type) 4-day intradermal induration consisting of predominantly polymorphonuclear leukocytes on day 1 and mononuclear cells by day 4, which is independent of the presence of tumor-specific antigens on the tumorigenic cells. Chemical carcinogen-induced morphologically transformed but nontumorigenic cells also induce a polymorphonuclear response by day 1, but neither induration nor a mononuclear response is present on day 4, demonstrating the specificity of the 4-day sustained indurative response for tumorigenic cells. Induration and cellular infiltrates are unaltered if tumor cells are treated prior to injection with the cytostatic lymphokine lymphotoxin or with x-irradiation to inhibit cell proliferation. The intradermal polymorphonuclear leukocyte host response on day 1, but not the mononuclear response on day 4, is also induced by mitomycin C-treated cells or a cytokine culture medium from the cells. No response is present on day 1 or day 4 when cell membranes or lyophilized cells are injected. Thus natural delayed-hypersensitivity-type skin reactivity is a mononuclear leukocyte response specifically directed against intact and metabolically active but not necessarily proliferating tumor cells.     

Evidence that the coproporphyrinogen oxidase activity of rat liver is situated in the intermembrane space of mitochondria.

Preferential rupture of the outer membrane of mitochondria from rat liver releases coproporphyrinogen oxidase in parallel with components of the intermembrane space. Coproporphyrinogen III enters the mitochondrion through the freely-permeable outer membrane. Either protoporphyrinogen IX or protoporphyrin IX must then cross the inner membrane before haem synthesis can be completed.