144 research outputs found
Characterisation of root-nodule bacteria isolated from perennial Southern African species of Lotononis
No full textLotononis is a genus of approximately 150 shrubs, herbaceous perennials and annuals belonging to the subfamily Fabaceae (Van Wyk, 1991). They are distributed mainly in southern Africa, with some species extending throughout Africa, southern Spain, Turkey, south-eastern Bulgaria and part of the Arabian Peninsula to the north-west of the Indian sub-continent (Van Wyk, 1991). Lotononis species have shown potential as perennial pasture legumes that can be used to help reduce the risk of dryland salinity in southern Australian agricultural systems. Species in the section Listia in particular may be useful as pasture legumes as they are perennial, stoloniferous, and lack the poisonous cyanogenic or alkaloid compounds found in some species of Lotononis. L. bainesii, from the Listia section, has been shown to grow well in southern Australia (Roberts & Carbon, 1969) and will grow on acid, sandy soils (R. Yates, pers. comm.).
L. bainesii is nodulated by pink-pigmented root-nodule bacteria. Jaftha et al. (2002) characterised nine L. bainesii isolates and found them to be related to Methylobacterium. The genus Methylobacterium, often referred to as pink-pigmented facultative methylotrophs (PPFMs), are capable of growth on C1 compounds such as formate and methanol as sole carbon sources. PPFMs are ubiquitous in the plant phyllosphere and rhizosphere, where they utilize methanol and other C1 compounds that are the products of plant metabolism (Trotsenko et al, 2001). They can promote the germination or the growth of plants, probably because of their ability to synthesise auxins, cytokinins and other plant growth promoting substances (Holland & Polacco, 1994; Ivanova et al., 2000; Trotsenko et al., 2001). However, until the paper by Sy et al. (2001), describing Methylobacterium nodulans, which was isolated from nodules of Crotalaria species found in Senegal, no Methylobacterium species had been known to nodulate legumes, or indeed to fix nitrogen.
The objectives in this study were to characterise root-nodule bacteria isolated from four species from the Listia section of Lotononis (L. angolensis, L. bainesii, L. listii and L. solitudinis) using a range of phenotypic and genetic techniques
Diversity of Methylobacterium Species Associated with New Zealand Native Plants
No full textThe genus Methylobacterium are pink-pigmented facultative methylotrophs (PPFMs), and are abundant colonizers of the phyllosphere, due to the availability of methanol, a waste product of pectin metabolism during plant cell division. Besides methanol cycling, Methylobacterium has important effects on plant health. The phyllosphere is an extreme environment with a landscape that is heterogeneous, continuously changing as the plant grows, and is exposed to very high ultra violet irradiation. Geographically, New Zealand has been isolated for over a million years, has a biologically diverse group of species, and is considered a biodiversity hotspot, with most of the native plants being endemic. We hypothesize that NZ native plants harbor diverse groups of Methylobacterium species, and to test this we aimed to isolate Methylobacterium species from the phyllosphere of native New Zealand plants. A leaf imprinting technique using methanol supplemented AMS agar media was used to isolate bacteria and diversity was determined using a combination of ARDRA, 16S rRNA gene sequencing and phylogenetic analysis. Methylobacterium spp. were successfully isolated from 19 of the 21 plant species used in this study. Eleven Methylobacterium species have been identified in association with the phyllosphere of native NZ plants: M. adhaesivum, M. brachiatum, M. komagatae, M. marchantiae, M. mesophilicum, M. phyllosphaerae, M. fujisawaense, M. oryzae, M. radiotolerans, M. tardum and M. zatmanii, with the first six being the most frequently isolated from more plant species. In this study other α, β, γ-proteobacterial species were also isolated: Hyphomicrobium, Methylopila, Rhizobium, Achromobacter, Methylophilus, Ramlibacter and Xanthomonas; Janibacter melonis (Actinomycetes); Niastella populi (Bacteroidetes) and Paenibacillus lautus (Firmicutes), highlighting the presence of potential novel methanol utilizer within the ecosystem. Results from this study indicate that Methylobacterium are abundant and dominant members of the NZ phyllosphere environment, with species diversity and composition dependent on the host plant species
Український модерн в архітектурі
No full textThis work is dedicated to the Ukrainian modern style, which spread throughout the territory of Ukraine in the first half of the 20th century. In it, unlike previous ones, there is a huge variety of forms in all elements of structures. The largest number of masterpieces has been preserved in Lviv, Kharkiv, Kyev and Odesa, erected by such famous creators of that era as Vasil Krichevsky, Viktor Trotsenko, Kostyantin Zhukov. The author concludes that this period is significant in the history of Ukraine
Methylophaga alcalica sp. nov., a novel alkaliphilic and moderately halophilic, obligately methylotrophic bacterium from an East Mongolian saline soda lake
No full textПрименение вариационных методов в некоторых контактных задачах статики мягких оболочек вращения
No full textWe propose a method for finding the finite deformations of hyperelastic domal shells of rotation due to hydrostatic load. The problem is considered under the condition that the deformed surface of the shell enters the domain of perfect contact with coaxial rigid surface. The efficiency of the suggested approach is assured by taking into account the singular properties of solutions on the line of transition of shell surface from free domain to the contact one and their asymptotic behavior in vicinity of the shell pole.
For a set of examples, which illustate the advantages of the algorithm, we present the basic dependences describing stressly-deformed state of a shell.На основi варiацiйного методу пропонується розв’язок задачi про скiнченнi деформацiї гiперпружних оболонок обертання пiд дiєю гiдростатичного навантаження за умови, що деформована поверхня оболонки вступає в зону iдеального контакту iз спiввiсно розмiщеною жорсткою поверхнею обертання. Ефективнiсть запропонованого пiдходу зумовлена врахуванням властивостей шуканих розв’язкiв на лiнiї переходу поверхнi оболонки вiд вiльної зони до контактної та асимптотичної поведiнки їх в околi полюса оболонки.
На конкретних прикладах проiлюстровано можливостi запропонованого алгоритму.The author is grateful to DFG for partial support
Cream in the context of the problem of sub-active "pro-music" musical culture
No full textУ статті розглянуто суб’єктні засади професійної музичної культури Криму. Подані портрети професійних композиторів регіону О.Спендіарова, А.Рефатова, Я.Шерфедінова, І.Бахшиша, А.Каврі, Р.Амзаєва, Е.Налбандова, О.Троценко, А.Караманова, М.Халітової, творчість яких вплинула на формування регіональної музичної культуриThe statti has a subtle ambush of the professional musical culture of Krimu. Submitting portraits of professional composers to the region O. Spendiarov, A. Refatov, Y. Sherfedinov, I. Bakhshish, A. Kavri, R. Amzaev, E. Nalbandov, O. Trotsenko, A. Karamanova, M. Khalitova, regional musical culture
Fundamentals of molecular evolution, 2nd Edition. By Dan Graur and Wen‐Hsiung Li, Sinauer Associates, Inc, Sanderland, Massachusetts, 2000, xiv + 481 pp, price £27.95. ISBN 0 87893 266 6
No full textPhysiology and Biochemistry of the Aerobic Methane Oxidizing Bacteria
No full textMethanotrophic bacteria grow aerobically using methane as a source of carbon and energy. They are widespread in the environment and play an important role in oxidizing methane in the environment, thereby mitigating the effects of global warming by this potent greenhouse gas. Methane monooxygenases (MMOs), which are the enzymes that catalyze the oxidation of methane, especially, the catalytically versatile soluble MMO, can cooxidize a wide range of hydrocarbons and chlorinated hydrocarbons, and have great potential as biocatalysts for bioremediation and biocatalysis. Methanotrophs can also be used to make single-cell protein from methane. Recent isolation of novel groups of thermophilic, acidophilic methanotrophs has revealed that these bacteria can even grow under extreme environmental conditions. The availability of genome sequences of several methanotrophs now opens up possibilities of postgenomic studies to investigate the regulation of methane oxidation in the laboratory and in the environment
Choosing the Most Correct Method to Predict the Distribution of Fractured Zones in Carbonate Reservoirs
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