Arthrobacter sp. yra dirvoje paplitusios bakterijos, kurios gali prisitaikyti prie nepalankių aplinkos sąlygų, tokių kaip osmosinis šokas ar maisto medžiagų trūkumas. Osmoreguliacijoje daugelis organizmų naudoja glicino betainą. Yra žinoma, kad Arthrobacter globiformis bakterijos gali panaudoti glicino betainą kaip anglies ir azoto šaltinį, tačiau nebuvo aišku, ar Arthrobacter globiformis gali šią medžiagą naudoti kaip osmoprotektorių. Iš Arthrobacter globiformis buvo klonuotas DNR fragmentas, kuriame buvo identifikuoti genai, kurie tiesiogiai ir netiesiogiai dalyvauja glicino betaino katabolizme. Struktūrinė genų organizacija leidžia manyti, kad šios bakterijos gali panaudoti glicino betainą kaip osmoprotektorių, Taip pat buvo įdomu patikrinti, ar tokią funkciją glicino betainas gali vykdyti ir kitose A. globiformis giminingose bakterijose. Tyrimui buvo pasirinkti tipiniai Arthrobacter genties bakterijų kamienai (A. atrocyaneus, A. citreus, A. crystalopoietes, A. globiformis, A. ramosus, A. sulfureus bei Arthrobacter spp. (KA3, P3, KA2V2, PY22, KA2, GAZ21, P2G, KA4, KA2V3, GAZ3, PRH1, PY21, VM22, VP23, RD1, VM22, VP22, VP3, VPW7, VPS4, 96, 94, 85, 68M, 83 68B, BL-3 ir 1-IN). Darbo metu paaiškėjo, kad šį junginį apsaugai nuo osmosinio streso naudoja tik dalis Arthrobacter genties bakterijų. Glicino betainas artrobakterėse dažniau naudojamas kaip anglies šaltinis. / Arthrobacter spp. are wide-spread soil bacteria, which are adapted to grow under osmotic stress and shortage in available carbon (energy) sources. Many organisms utilise glycine betaine as an osmoprotectant. It is known, that Arthrobacter globiformis can use glycine betaine as a sole carbon and nitrogen source, however, it is unclear whether this bacterium use this substrate as osmoprotectant. A DNA fragment harbouring genes, which directly and indirectly are involved in glycine betaine degradation, was cloned from A. globiformis. The structural organization of these genes suggested, that this bacterium could use glycine betaine as an osmoprotectant. So, it was tested if other Arthrobacter spp. strains use glycine betaine to protect from osmotic stress. Typical Arthrobacter sp. strains (A. atrocyaneus, A. citreus, A. crystalopoietes, A. globiformis, A. ramosus, A. sulfureus and Arthrobacter spp. (KA3, P3, KA2V2, PY22, KA2, GAZ21, P2G, KA4, KA2V3, GAZ3, PRH1, PY21, VM22, VP23, RD1, VM22, VP22, VP3, VPW7, VPS4, 96, 94, 85, 68M, 83 68B, BL-3 and 1-IN) were chosen in this study. It turned out, that less than a half of studied strains use glycine betaine as osmoprotectant. The arthrobacters used glycine betaine more as a sole carbon source than as an osmoprotectant.

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-06T19:03:57Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Wagner J. C. Sousa.pdf: 722513 bytes, checksum: 9211c11741fd34cc4bf153dbe3190808 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-06T19:04:10Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Wagner J. C. Sousa.pdf: 722513 bytes, checksum: 9211c11741fd34cc4bf153dbe3190808 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-06T19:04:22Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Wagner J. C. Sousa.pdf: 722513 bytes, checksum: 9211c11741fd34cc4bf153dbe3190808 (MD5) / Made available in DSpace on 2017-02-06T19:04:22Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Wagner J. C. Sousa.pdf: 722513 bytes, checksum: 9211c11741fd34cc4bf153dbe3190808 (MD5) Previous issue date: 2016-04-15 / From the environmental-conservation point of view, the search of renewable energy sources is certainly one of the most important strategies for all countries aiming for the sustainable development. Among them, the use of biodiesels replacing fossil fuels constitutes an important step towards this direction. Chemically, biodiesels are mixture of esters with long carbon chains. They can be obtained from vegetable oils or animal fats via transesterication. In this sense, the investigation on electron interaction with small esters is important which may help to the understanding of combustion of biodiesels. Despite that, to our knowledge, there are no other experimental or theoretical studies of electron collisions with such class of compounds. In the present study, we report a theoretical study on electron collisions with methyl formate. More specifically, elastic differential (DCS), integral (ICS), and momentumtransfer (MTCS) cross sections, as well as grand-total (TCS) and total absorption (TACS) cross sections for electron scattering by methyl formate were determined in the 1-500 eV energy range, using a combination of molecular complex optical potential (MCOP) and Padé approximant method. / Do ponto de vista da conservação ambiental, a busca por fontes de energias renováveis é certamente uma das estratégias mais importantes para qualquer país que almeja o desenvolvimento sustentável. Dentre essas fontes, a utilização de biocombustíveis ao invés de combustíveis fósseis constitui um passo importante nessa direção. Quimicamente, o biodiesel é formado por uma mistura de ésteres de cadeias longas, podendo ser obtidos através de transesterificação de gorduras vegetais ou animais, por exemplo. Nesse sentido, a investigação da interação de elétrons com ésteres menores pode ser um importante passo inicial para auxiliar no entendimento do mecanismo detalhado da combustão do biodiesel. Apesar dessa importância, em meu conhecimento, não existia até o momento qualquer trabalho experimental ou teórico sobre espalhamento de elétrons pela referida classe de compostos. Foi com o intuito de auxiliar no preenchimento dessa lacuna que o presente trabalho foi realizado. Neste foram realizado um estudo teórico da colisão de elétrons com a molécula de Formiato de Metila (HCOOCH3). Mais especificamente, foram calculadas as seções de choque diferenciais elásticas (SCD), integrais elásticas (SCI), de transferência de momento (SCTM), totais (SCT) e de absorção total (SCAT), na faixa de 1-500 eV. Os cálculos foram efetuados a partir do uso de um potencial óptico complexo juntamente com o método dos aproximantes de Padé.