CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Este trabalho teve por finalidade avaliar algumas variÃveis fisiolÃgicas e bioquÃmicas de duas espÃcies de sorgo forrageiro submetidas a diferentes condiÃÃes de cultivo e de salinidade. Para isso, foram montados dois experimentos. No primeiro deles estudou-se tais variÃveis em Sorghum bicolor e Sorghum sudanense, em funÃÃo de diferentes nÃveis de estresse salino, enquanto no segundo, as variÃveis foram estudadas em duas fases distintas de desenvolvimento das duas espÃcies de sorgo, visando determinar em qual delas essas espÃcies sÃo mais resistentes aos efeitos deletÃrios da salinidade. No primeiro experimento, os tratamentos foram dispostos em esquema fatorial 2 à 5, composto por duas espÃcies (S. bicolor e S. sudanense) e cinco tratamentos (NaCl a 0, 25, 50, 75 e 100 mM). Nesse experimento, os parÃmetros de trocas gasosas foram pouco afetados pela salinidade, em ambas as espÃcies. O crescimento das plantas de ambas as espÃcies reduziu à medida que a salinidade aumentou. O potencial osmÃtico (s) foliar foi fortemente reduzido pela salinidade nessas plantas, a qual aumentou significativamente a concentraÃÃo de solutos orgÃnicos nas duas espÃcies de sorgo. As concentraÃÃes de Na+ e Cl- aumentaram com a salinidade em ambas as espÃcies. S. bicolor e S. sudanense mantiveram o teor relativo de Ãgua sob condiÃÃes salinas igual ao do controle. Nas espÃcies de sorgo estudadas, os carboidratos solÃveis e os Ãons K+ e Cl- foram os que mais contribuÃram para o ajustamento osmÃtico das plantas. Nas folhas de S. bicolor, houve um aumento na atividade das peroxidases do ascorbato (APX) e do guaiacol (GPX) e uma reduÃÃo na atividade da catalase (CAT), enquanto a dismutase do superÃxido (SOD) nÃo foi afetada. Em S. sudanense, à medida que foram elevadas as doses de NaCl, observou-se um aumento na atividade da GPX e da SOD. Nas raÃzes, apenas a SOD apresentou aumento em atividade no S. bicolor. A atividade ribonucleÃsica nas folhas de ambas as espÃcies aumentou com as doses crescentes de NaCl, enquanto que nas raÃzes, ela foi reduzida à medida que o estresse salino intensificou-se. No segundo experimento, os tratamentos foram arranjados em esquema fatorial 2 à 3 à 2, composto por duas espÃcies (S. bicolor e S. sudanense), trÃs concentraÃÃes de sais na Ãgua de irrigaÃÃo (condutividades elÃtricas de 0,0; 4,0 e 8,0 dS m-1) e dois perÃodos de aplicaÃÃo do estresse salino Ãs plantas [desde a semeadura atà 25 dias depois (Fase I) e do 25 ao 50 dia apÃs a semeadura (Fase II)], com cinco repetiÃÃes. As principais alteraÃÃes nas trocas gasosas ocorreram na Fase II do desenvolvimento. O estresse salino reduziu o crescimento das plantas de sorgo em ambas as fases de desenvolvimento, porÃm essa reduÃÃo foi mais acentuada na Fase I. Os teores dos solutos orgÃnicos variaram em funÃÃo das fases de desenvolvimento, da espÃcie e da salinidade. Na Fase I, em ambas as espÃcies de sorgo, houve acrÃscimos nos teores de Na+ e K+ e reduÃÃo nos de Cl- pela salinidade, enquanto que, na Fase II do desenvolvimento, os teores de Na+ e K+ foram reduzidos e os de Cl-, aumentados, tanto em S. bicolor como em S. sudanense. Na Fase I do desenvolvimento, apenas a SOD, em S. bicolor, e a CAT, em S. sudanense, mostraram incrementos de atividade em resposta ao estresse salino. Jà na Fase II, nenhum aumento na atividade do sistema enzimÃtico antioxidativo foi observado em funÃÃo da salinidade, nas duas espÃcies estudadas. Na Fase I, a atividade da RNase, em ambas as espÃcies, foi reduzida com a salinidade, enquanto na Fase II do desenvolvimento, ela foi aumentada. O crescimento das plantas de S. sudanense foi ligeiramente mais afetado que o de S. bicolor. As espÃcies de sorgo forrageiro estudadas neste trabalho foram capazes de reduzir o s foliar em concentraÃÃes elevadas de NaCl, o que pode ter contribuÃdo para um melhor ajustamento osmÃtico. AlÃm disso, nas condiÃÃes empregadas no primeiro experimento, S. bicolor pareceu ter um sistema antioxidante mais eficaz contra os efeitos da salinidade do que S. sudanense. Em relaÃÃo ao segundo experimento, o crescimento das plantas de sorgo forrageiro foi mais afetado quando o estresse salino foi aplicado em estÃdios iniciais do desenvolvimento. O estresse oxidativo causado pela salinidade parece nÃo ter sido suficiente para estimular o sistema de defesa enzimÃtico antioxidativo na Fase II do desenvolvimento, em ambas as espÃcies. AlÃm disso, o aumento na atividade RNÃsica pode indicar o papel desta enzima na proteÃÃo contra os efeitos deletÃrios da salinidade nessas espÃcies de sorgo. De modo geral, nÃo houve diferenÃas marcantes na tolerÃncia das plantas de S. bicolor e S. sudanense à salinidade. / This study aimed to evaluate some physiological and biochemical variables of two species of sorghum subjected to different growing conditions and salinity. For this, two experiments were set up. In the first study, the variables in Sorghum bicolor and Sorghum sudanense were evaluated according different levels of salinity stress. In the second, the variables were studied in two distinct phases of development of two species of sorghum, to determine which one of these species are more resistant to the deleterious effects of salinity. In the first experiment, treatments were arranged in a 5 à 2 factorial, consisting of two species (S. bicolor and S. sudanense) and five treatments (NaCl at 0, 25, 50, 75 and 100 mM). In this experiment, the gas exchange parameters were little affected by salinity in both species. Plant growth of both species decreased as salinity increased. The osmotic potential (ψs) leaves was strongly reduced by salinity in these plants, which significantly increased the concentration of organic solutes in the two species of sorghum. The concentrations of Na+ and Cl- increased with salinity in both species. S. bicolor and S. sudanense maintained relative water content under saline conditions the same as the control. In sorghum species studied, the soluble carbohydrates and the ions K+ and Cl- were the main contributors to the osmotic adjustment of plants. In leaves of S. bicolor, there was an increase in activity of ascorbate peroxidase (APX) and guaiacol (GPX) and a reduction in activity of catalase (CAT), while superoxide dismutase (SOD) was not affected. In S. sudanense, the activity of GPX and SOD increased with increasing salinity. In roots, just SOD activity in S. bicolor were increased with salt stress. Ribonuclease activity in the leaves of both species increased with increasing doses of NaCl, whereas in roots it was reduced as the salt stress intensified. In the second experiment, treatments were arranged in a factorial 2 à 3 à 2, composed of two species (S. bicolor and S. sudanense), three concentrations of salts in irrigation water (electrical conductivities of 0.0, 4.0 and 8.0 dS m-1) and two periods of application of salt stress to plants [from sowing until 25 days later (Phase I) and from 25th to 50th day after sowing (Phase II)], with five repetitions. The main changes in gas exchange occurred in Phase II development. The salt stress reduced plant growth of sorghum in both phases of development, but this reduction was more pronounced in Phase I. The levels of organic solutes varied according to the phases of development, species and salinity. In Phase I, in both species of sorghum, there were increases in levels of Na+ and K+ and reduced Cl- by salinity, whereas in Phase II development, the levels of Na+ and K+ were reduced and Cl- extended, both in S. bicolor as in S. sudanense. In Phase I of development, only SOD in S. bicolor, and CAT in S. sudanense showed activity increases in response to salt stress. In the Phase II, no increase in the activity of antioxidant enzyme system was observed as a function of salinity in both species. In Phase I, the activity of RNase in both species was reduced by salinity, while in Phase II development, it was expanded. Plant growth of S. sudanense was slightly more affected than the S. bicolor. Sorghum species studied in this work were able to reduce the leaf ψs high concentrations of NaCl, which may have contributed to a better osmotic adjustment. In addition, under the conditions employed in the first experiment, S. bicolor appeared to have a more effective antioxidant system against the effects of salinity than S. sudanense. For the second experiment, the growth of sorghum plants was more affected when the salt stress was applied in the early stage of development. The oxidative stress caused by salinity seems to have been sufficient to stimulate the enzymatic antioxidant defense system in Phase II development in both species. Furthermore, increased activity RNase may indicate the role of this enzyme in protecting against the deleterious effects of salinity in these species of sorghum. Overall, there were no marked differences in plant tolerance between S. bicolor and S. sudanense under salinity.

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / A mamona (Ricinus communis) à uma cultura em ascensÃo que precisa de tÃcnicas de produÃÃo adequadas à suas condiÃÃes de cultivo e ao seu nicho de mercado. Essa cultura tem sido estudada com a finalidade de melhor adequÃ-la Ãs condiÃÃes ambientais do Norte e Nordeste brasileiros, regiÃes estas com problemas vigentes e potenciais de salinidade. Desse modo, a caracterizaÃÃo dos efeitos deletÃrios da salinidade em sementes e plÃntulas de mamona e a avaliaÃÃo do uso das tÃcnicas de condicionamento fisiolÃgico de sementes podem convergir em uma forma de se reduzir custos com replantios, uniformizar a plantaÃÃo e preparar as plÃntulas para melhor enfrentar o estresse salino. O objetivo geral da pesquisa foi caracterizar os efeitos deletÃrios da salinidade em sementes de mamona e avaliar o uso das tÃcnicas de condicionamento fisiolÃgico de sementes como meio de minimizÃ-los. A salinidade afetou a germinaÃÃo das sementes de mamona cv. BRS-Energia apenas a partir do Ψs de -0,4 MPa de soluÃÃes de NaCl, porÃm, o crescimento das plÃntulas foi afetado sob Ψs de -0,16 MPa. A curva de embebiÃÃo de Ãgua pelas sementes sob salinidade, mostrou-se desacelerada com o tempo de exposiÃÃo à salinidade. A atividade da enzima dismutase do superÃxido nÃo foi afetada da salinidade, enquanto das enzimas catalase e peroxidase do ascorbato foram responsivas à salinidade. NÃo foi detectada atividade da enzima peroxidase do guaiacol nas sementes de mamona. Apesar dos osmocondicionamentos com CaCl2, NaNO2 e PEG-6000, testados sob condiÃÃes salinas, terem demonstrado bons resultados, o condicionante com maior destaque foi o NaNO3, sendo este portanto o mais recomendado para as sementes de mamona cv. BRS-Energia. / Castor bean (Ricinus communis) is a rise culture that needs production techniques appropriate to its growth conditions and niche market. Several researches have been conduct to adapt its development in the North and Northeast regions of the Brazil, which are regions with increase salinity problem. Thus, the seed and seedling salinity effects characterization and the evaluation of seed priming techniques can reduce the replanting costs and improve emergency uniformity, preparing the plant to response the salt stress. The overall objective of the research was to characterize the deleterious effects of salinity on castor bean seeds and evaluate the use of the techniques of seed priming as a means of minimizing them. Salinity affected the germination of castor bean cv. Energy only from the osmotic potential (Ψs) of -0.4 MPa, but seedling growth was affect under Ψs of -0.16 MPa. The water imbibition curve by the seed under salinity was decelerate with time of exposure to salinity. The enzymatic activity of superoxide dismutase are independent of salinity, while catalase and ascorbate peroxidase was responsive to salinity. There were no detectable enzyme activity of guaiacol peroxidase in the seeds of castor bean. However, despite osmopriming with CaCl2, NaNO2 and PEG-6000, tested under saline conditions, have shown good results, most notably the priming was NaNO3, this being the most recommended as priming to castor bean seeds.

Células de Nicotiana tabacum cv BY-2 foram tratadas por cinco dias com 0,075 e 0,750 mM de NiCl2. A relação entre a toxidade do níquel (Ni) e as reações oxidativas foram estudadas nas células durante a acumulação do metal. A atividade da superóxido dismutase não se alterou na presença do Ni. Entretanto, as atividades da catalase e da guaiacol peroxidase aumentaram às 36 e 72h depois do tratamento com o metal. As atividades da glutationa redutase, da glutationa-Stransferase e da ascorbato peroxidase aumentaram nas primeiras horas do tratamento. A peroxidação lipídica da membrana aumentou somente às 24h do tratamento com o metal. Os resultados sugerem que a desordem oxidativa é resultante dos efeitos da toxidade do Ni nas células de Nicotiana tabacum cv BY-2. / Células de Nicotiana tabacum cv BY-2 foram tratadas por cinco dias com 0,075 e 0,750 mM de NiCl2. A relação entre a toxidade do níquel (Ni) e as reações oxidativas foram estudadas nas células durante a acumulação do metal. A atividade da superóxido dismutase não se alterou na presença do Ni. Entretanto, as atividades da catalase e da guaiacol peroxidase aumentaram às 36 e 72h depois do tratamento com o metal. As atividades da glutationa redutase, da glutationa-Stransferase e da ascorbato peroxidase aumentaram nas primeiras horas do tratamento. A peroxidação lipídica da membrana aumentou somente às 24h do tratamento com o metal. Os resultados sugerem que a desordem oxidativa é resultante dos efeitos da toxidade do Ni nas células de Nicotiana tabacum cv BY-2.

<p>U radu je ispitivan efekat dodatka čiste melase i voda/povrda (jabuke, &scaron;ljive, mrkva i crveni kupus), prethodno osmotski dehidriranih u melasi &scaron;ederne repe, na kvalitet hleba. Ispitivane su sledede grupe suplemenata u dve doze: čista melasa (5 i 10%, računato na bra&scaron;no), sveži (u obliku komadida osmotski dehidriranog voda/povrda, 10 i 30%, računato na bra&scaron;no) spra&scaron;eni (osu&scaron;eno i samleveno osmotski dehidrirano vode/povrde, 5 i 10%, računato na bra&scaron;no).<br />Dobijeni rezultati su pokazali da su ispitivani dodaci uticali na značajno pobolj&scaron;anje mineralnog sastava hleba. Najznačajni je povedanje u odnosu na kontrolni je zabeleženo u sadržaju kalijuma: za niže doze dodataka, najvede povedanje se kretalo u opsegu 89.1% (hleb sa melasom)-94.1% (hleb sa &scaron;ljivom u prahu) dok su za vi&scaron;e doze dodataka zabeležena slededa maksimalna povedanja:<br />157.5% (hleb sa kupusom u prahu) i 167.5% (hleb sa melasom). Hlebovi sa dodacima su takođe imali značajno vi&scaron;e sadržaje magnezijuma i kalcijuma u odnosu na kontrolni hleb. Najvi&scaron;i sadržaji Mg i Ca su određeni u hlebovima sa dodatkom vi&scaron;e doze kupusa u prahu (58 i 100%, respektivno). Hlebovi sa dodacima su pokazivali značajno vi&scaron;i antioksidacioni potencijal, pri čemu su najvi&scaron;i potencijali zabeleženi u hlebu sa dodatkom &scaron;ljive u prahu, 62.5-81.6% za 5 i 10% dodatak, respektivno.<br />Dodaci na bazi melase su uticali na promenu fizičkih, teksturnih i senzorskih svojstava hleba u pravcu smanjenja specifične zapremine, povedanja čvrstode sredine i potamnjivanja boje. Međutim, pri nižim dozama dodataka, ove promene su bile manje izražene. Hlebovi sa dodatkom jabuke i &scaron;ljive su ocenjeni kao najbolji po ukusu.</p> / <p>Osmotical dehydration in sugar beet molasses as hypertonic medium was used to treat apples, plums, carrots and red cabbage. Following the treatment, the fruits/vegetables were dried and ground. The study was aimed at determining the quality parameters of bread supplemented with the following ingredients: The freshly treated fruits/vegetables (at 10% and 30% level, flour basis), The powders derived from them (at 5% and 10% level flour basis), Sugar beet molasses (at 5% and 10% level flour basis).<br />The results showed that these ingredients significantly improved the mineral content of breads. The most marked was the increase in K content: for lower supplementation level, 89.1% (bread with<br />molasses)-94.1% (bread with plum, powder). For higher supplementation level, the rise in K content was 157.5% (bread with cabbage, powder) and 167, 5% (bread with molasses). Contents of Mg and Ca were also significantly increased as compared to the control. The highest increase in Mg and Ca was obtained by supplementation with cabbage at higher applied dose (around 58% and 100%, respectively). Moreover, the supplemented breads showed significantly higher antioxidant potentials with the highest increase measured in the breads made with plum (62.5-81.6% for 5 and 10% levels, respectively). The molasses-based ingredients influenced the physical, textural and sensory properties of bread by lowering the specific volume, increasing the crumb firmness and changing the color and flavor. However, the lower supplementation levels had relatively mild effect on these properties. The breads made with apples and plums were scored highest for flavor.</p>

<p>Istraživanja&nbsp; u&nbsp; ovoj&nbsp; doktorskoj&nbsp; disertaciji&nbsp; su&nbsp; bila&nbsp; usmerena&nbsp; ka&nbsp; razumevanju<br />molekularnih&nbsp; mehanizama&nbsp; koji&nbsp; se&nbsp; aktiviraju&nbsp; kod medonosne pčele (<em>Apis mellifera, L</em>.)&nbsp; kao&nbsp; odgovor&nbsp; na&nbsp; stres&nbsp; izazvan&nbsp; jonima&nbsp; te&scaron;kih&nbsp; metala,&nbsp; &scaron;to&nbsp; zbog važnosti medonosne pčele kao opra&scaron;ivača&nbsp; ima&nbsp; poseban&nbsp; značaj&nbsp; i&nbsp; očekuje&nbsp; se da će doprineti očuvanju ove vrste. Istraživanja su bila podeljena u tri faze. U prvoj fazi za analize&nbsp; su&nbsp; kori&scaron;ćene populacije pčela sa lokaliteta sa različitim&nbsp; antropolo&scaron;kim uticajem&nbsp; i izmerena je koncentracija metala u pčelama, pergi i medu, kao i relativna genska ekspresija i aktivnost antioksidativnih enzima. U drugoj fazi&nbsp; pčele&nbsp; su&nbsp; u kontrolisanim laboratorijskim uslovima bile&nbsp; izložene subletalnim dozama jona te&scaron;kih&nbsp;metala&nbsp; (bakra,&nbsp; kadmijuma i olova), nakon čega&nbsp; su&nbsp; izmereni parametri koji ukazuju na redoks status i nivo oksidativnog stresa. Rezultati prve dve faze su pokazali&nbsp; da se ekspresija gena i aktivnost antioksidativnih enzima (superoksid dismutaze, katalaze i glutation&nbsp;<em> S</em>-transferaze)&nbsp; razlikuje u zavisnosti od stepena urbanizacije i industrijalizacije, dok je izlaganje bakru i kadmijumu u kontrolisanim uslovima u trajanju od 48 h dovelo samo do promene&nbsp; u ekspresiji gena&nbsp; i u većini slučajeva ekspresija je bila dozno zavisna od koncentracije metala.&nbsp; Olovo je uzrokovalo promene u koncentraciji glutationa i sulfhidrilnih grupa proteina, &scaron;to govori o tome da helacija olova može da bude prvi mehanizam odbrane od toksičnih efekata ovog metala.&nbsp; U trećoj fazi bioinformatičkom analizom je&nbsp; pronađen metalotionein medonosne pčele i ispitana je njegova funkcija u za&scaron;titi od toksičnih efekata jona te&scaron;kih metala.&nbsp; Utvrđeno je da pčele poseduju jedan&nbsp;gen za metalotionein, koji kodira mali protein sa regionima bogatim cisteinom za koje mogu da se vežu joni metala. Indukcija genske ekspresije metalotioneina medonosne pčele nakon izlaganja metalima i povećana tolerancija bakterija koje ekspresuju rekombinantni metalotionein na metale je potvrdila da metalotionein medonosne pčele ima ulogu u homeostazi bioelemenata i detoksikaciji potencijalno toksičnih metala.&nbsp; Dobijeni rezultati predstavljaju osnovu za buduća istraživanja uticaja&nbsp; jona te&scaron;kih metala na medonosnu pčelu i predstavljaju važan korak u sveobuhvatnoj proceni uticaja stresogenih faktora iz životne sredine na pčele.</p> / <p>Research in this doctoral thesis&nbsp; focuses&nbsp; on&nbsp; understanding the molecular mechanisms activated in the honey bee (Apis mellifera L.) as a response to stress caused by exposure to heavy metal ions. Because of the importance of honeybees as pollinators, this has special significance and is expected to contribute to the&nbsp; conservation of this species. Studies have been divided into three phases. In the first phase, bee populations from&nbsp; three localities under&nbsp; different anthropological influence were used and the concentrations of metals in the bees, honey and bee bread&nbsp; (perga), as well as relative gene expression and activity of antioxidant enzymes were measured. In the second phase, bees&nbsp; were exposed to sublethal doses of heavy metal ions (copper, cadmium and lead) under controlled laboratory conditions, after which parameters that indicate redox status and oxidative stress were determined. The results of the first two phases showed that&nbsp; gene expression and activity of antioxidant enzymes (superoxide dismutase, catalase, and glutathione&nbsp; S-transferase) varies depending on the degree of urbanization and industrialization, while exposure to copper and cadmium in controlled conditions for 48 h&nbsp; resulted only in a change in gene expression in the majority of cases, and the expression was dose-dependent on the concentration of the metal. Lead has caused changes in the concentration of glutathione and sulfhydryl groups of proteins, which indicates&nbsp; that chelation may be the first defense mechanism against&nbsp; the&nbsp; toxic effects of this metal. In the third stage, honeybee metallothionein was identified by bioinformatic analysis and its function in&nbsp; protection against the toxic effects of heavy metal ions was examined. It has been found that&nbsp; honeybees have one metallothionein gene, which encodes a small protein with cysteine-rich regions that may bind metal ions. The induction of metallothionein gene expression after exposure of honeybees to metals and increased tolerance of bacteria that express recombinant metallothionein confirmed that this protein plays a role in the homeostasis of bioelements and detoxification of potentially toxic metals. These results form the basis for future research on the impact of&nbsp; heavy metal pollution on the honey bee and represent an important step in the comprehensive assessment of the impact of stress factors from the environment on honey bees.</p>

<p>Proizvodnja fermentisanih mliječnih napitaka unapreijeđenih funkcionalnih karakteristika postala je jedan od glavnih fokusa u industriji prerade mlijeka. Cilj doktorske disertacije je ispitivanje biolo&scaron;ke aktivnosti fermentisanih mliječnih napitaka dobijenih primjenom nekonvencionalne starter kulture, kombuhe (kultivisane na crnom čaju zaslađenim saharozom u koncentraciji od 10%) i poređenje sa karakteristikma proizvoda dobijenih primenom konvencionalnih starter kultura, jogurtne odnosno probiotske, tokom skladi&scaron;tenja. Za fermentaciju je kori&scaron;ćeno mlijeko sa 2,8% mliječne masti na temperatura 42&deg;C.<br />Promjene tokom fermentacije mlijeka primjenom kombuhe i konvencionalnih starter kultura praćene su određivanjem stepena proteolize, sadržaja laktoze, D&ndash; galaktoze, D&ndash;glukoze i D&ndash;fruktoze i masnih kiselina pri sledećim pH vrijednostima: 6,4; 6,0; 5,5; 5,0 i 4,6. Promjene antihipertenzivne aktivnosti (AKE inhibitorna aktivnost), antioksidativne aktivnosti (ABTS i DPPH metod) kao i promjene stepena proteolize, reolo&scaron;kih i senzornih karakteristika sve tri vrste fermentisanih mliječnih napitaka praćene su tokom 21-og dana skladi&scaron;tenja. Osim toga praćene su i promjene sadržaja &scaron;ećera, masnih kiselina, minerala (kalcijuma, natrijuma i kalijuma), vitamina C i biogenih amina.<br />Tokom procesa fermentacije mlijeka primjenom različitih starter kultura može se zaključiti da postoji razlika u promjenama udijela pojedinačnih proteinskih frakcija analiziranih metodom kapilarne elektroforeze.<br />Različite starter kulture utiču na različitu AKE inhibitornu aktivnost tokom skladi&scaron;tenja, &scaron;to ukazuje na različitu proteolitičku aktivnost kori&scaron;ćenih starter kultura. Utvrđeno je da AKE inhibitorna aktivnost raste tokom skladi&scaron;tenja, pri čemu uzorci proizvedeni primjenom kombuhe imaju najveću AKE inhibitornu aktivnost na kraju 14 dana skladi&scaron;tenja i ona iznosi 79,4%, dok su u jogurtu i probiotskom jogurtu te vrijednsoti 63,4 i 64,6% redom. Takođe, tokom skladi&scaron;tenja stepen proteolize raste u svim uzorcima sa značajnim međusobnim varijacijama. Antiksidativna aktivnost svih uzoraka opada tokom skladi&scaron;tenja ali je u svim uzorcima zabilježena veća aktivnost na ABTS nego na DPPH slobodne radikale. Nakon 21-og dana skladi&scaron;tenja najveći antioksidativni potencijal određen metodom stabilizacije ABTS.+ katjona imali su uzorci sa jogurtnom starter kulturom (TEAC vrijednost 8,922 mmolmg-1). U pogledu sastava masnih kiselina, tokom 14 dana skladi&scaron;tenja u kombuha fermentisanim mliječnim napicima<br />kao i napicima dobijenim sa jogurtnom i probiotskom starter kulturom dolazi do porasta udjela zasićenih (SFA) i opadanje mononezasićenih (MUFA) i polinezasićenih masnih kiselina (PUFA). Nakon 21-og dana skladi&scaron;tenja sadržaj SFA; MUFA i PUFA u kombuha fermentisanom mliječnom napitku iznosio je 65,94; 30,73 i 3,33% redom, dok su te vrijednosti kod jogurta iznosile 66,02; 30,77 i 3,21% i probiotskog jogurta 66,04; 30,66 i 3,30 % redom. Najveći sadržaj vitamina C nakon proizvodnje i 14 dana skladi&scaron;tenja imali su uzorci sa kombuha starter kulturom (0,5457 &plusmn; 0,017 mg100g-1). Uzorci dobijeni upotrebom konvencionalnih startera pokazali su bolje reolo&scaron;ke osobine pri ispitivanim uslovima tokom 21 dana skladi&scaron;tenja. Kombuha fermentisani mlečni proizvod imao je karakterističan, blago kiseli, osvežavajući ukus i nagla&scaron;enu aromu.<br />Na osnovu dobijenih rezultata biolo&scaron;ke aktivnosti i promjena kvaliteta kombuha fermentisanog mliječnog napitka tokom skladi&scaron;tenja, u odnosu na karakteristike proizvoda dobijenih upotrebom konvencionalnih starter kultura može se objasniti opravdanost upotrebe kombuha starter kulture u fermentaciji mlijeka sa ciljem dobijanja novog funkcionalnog fermentisanog mliječnog proizvoda.</p> / <p><span style="font-size:11px;">Nowadays, production of fermented dairy products with elevated benefits on human health has become one of the major focuse in dairy industry. The aim of the PhD thesis is to examine the biological activity of fermented milk products obtained using non-conventional starter culture kombucha (cultivated on black tea with 10% of sucrose) and comparision with products obtained by conventional starter cultures, probiotic/yoghurt during storage. Milk with 2.8% of milk fat was used for the samples production at temperature of 42 &deg;C.<br />The changes of components content during the milk fermentation by kombucha and conventional starter cultures were monitored at the following pH values: 6.4; 6.0; 5.5; 5.0 and 4.6., by determining the degree of proteolysis, lactose, D-galactose, D-glucose and D-fructose, fatty acids. The antihypertensive activity (ACE inhibitory activity), antioxidant activity (ABTS and DPPH tests) and the degree of proteolysis, sensory and rheological characteristics of all three types of fermented milk products were observed during 21 days of storage. Moreover, the chemical qualities of samples were monitored analyzing the contents of sugars, fatty acids, minerals (calcium, sodium and potassium), vitamin C and biogenic amines.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; There were differences in protein fractions (analyzed by capillary electrophoresis) of products obtained by using different starter cultures during the milk fermentation. Different starter cultures affect different ACE inhibitory activity during the storage, which implies different proteolytic activity of used starter cultures. It has been found that the ACE inhibitory activity was increased during the storage; wherein the samples obtained using kombucha starter culture have the highest ACE inhibitory activity at the 14th day of storage, 79,4%, while in yogurt and probiotic yoghurt it was 63.4 and 64.6% respectively. Also, the degree of proteolysis during the storage was increased in all samples with significant mutual variations. In all products, higher ABTS than 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was determined, while both activities slightly decreased during the storage. The antioxidant activity of all samples decreases during storage. After 21 days of storage, the highest antioxidant potential, determined by the ABTS. + method had a yoghurt samples (TEAC value of 8.922 mmolmg-1). In terms of the fatty acids composition during 14 days of storage in all type of fermented dairy products relative content of SFA (saturated fatty acids - SFA) increased, while relative contents of MUFA (monounsaturated fatty acids) and PUFA (polyunsaturated fatty acids) decreased during that period of storage. After 21 days of storage the content of SFA; MUFA and PUFA in kombucha fermented milk product was 65.94; 30.73 and 3.33% respectively. In yogurt sample their content was 66.02, 30.77 and 3.21%, while in probiotic 66.04; 30.66 and 3.30% respectively. In all fermented milk products, long chain fatty acids were dominant with a total share of about 45% in all varieties of fermented dairy products. The highest content of vitamin C after production and 14 days of storage was in samples obtained by kombucha starter culture (0.5457 &plusmn; 0.017 mg100g-1). Samples obtained by conventional starter showed better overall rheological properties at the tested conditions for 21 days of storage. Kombucha fermented milk product had a characteristic, distinctive mild sour, refreshing taste and conspicuous aroma.<br />The obtained results of biological activity and the quality of kombucha fermented milk products during storage in comparison to the same characteristics of the products obtained using conventional starter culture, could explain that kombucha is convenient starter for milk fermentation with the aim of obtaining new functional fermented milk products with pronounced bioactive characteristics and distinctive sensory and rheology properties.</span></p>

Oxidative stress is caused by overproduction and overaccumulation of ROS (reactive oxygen species). This state is responsible for cellular damage during unfavorable environmental conditions such as drought, low temperatures, salinity. In order to directly study oxidative stress at tobacco plants (Nicotiana tabacum cv. Xanthi) I used specific herbicides, MV (methyl viologen) and 3-AT (3- aminotriazole). There were several markers used for monitoring oxidative damage to cellular components: DNA damage detected by a comet assay, lipid peroxidation, carbonylated proteins and modification of activities of antioxidant enzymes CAT (catalase) and APX (ascorbate peroxidase). Fluorescent microscopy documented changes in a redox state of tobacco cells and a specific signal for peroxisomes was observed after treatment with higher concentrations of MV and 3-AT. Application of both herbicides caused significant DNA damage, while they worked in a different concentrations, MV in µM and 3-AT in mM. Another convincing oxidative stress marker for MV was protein carbonylation. The inhibition of antioxidant enzymes CAT and APX was less significant when compared to the effects of 3-AT. Decreasing membrane stability proved to be an universal oxidative stress marker for both herbicides. On the other hand, lipid...

O nitrogênio é um dos nutrientes que mais altera a produtividade das plantas forrageiras e as formas de fornecimento desse nutriente podem alterar as respostas das plantas. Objetivou-se avaliar as alterações morfogênicas, nutricionais, metabólicas e produtivas do capim tanzânia (Panicum maximum cv. Tanzânia), em função do fornecimento de doses de nitrogênio e proporções de NO3-/NH4+ na solução nutritiva. O experimento foi conduzido em casa de vegetação, com emprego de substrato inerte e avaliando três doses de nitrogênio para fornecer nutrição baixa, intermediária e alta em nitrogênio (3, 15 e 27 mmol L-1) e três proporções de NO3-/NH4+ não fornecendo e até suprindo amônio em relativo excesso (100/0, 70/30 e 40/60). As plantas foram submetidas a dois cortes da parte aérea e as raízes foram coletadas após o segundo corte. Foram avaliados o número de folhas e perfilhos, taxas de aparecimento de folhas e perfilhos, área foliar, produção de massa seca de parte aérea e de raízes, concentrações de nitrogênio total, NO3- e NH4+ nos tecidos vegetais, valor SPAD, concentrações de malondealdeído (MDA) e peróxido de hidrogênio e atividades das enzimas redutase do nitrato, glutamina sintetase, catalase, superóxido dismutase e glutationa redutase. A baixa dose de nitrogênio comprometeu a área foliar e produção de massa seca em ambos os crescimentos do capim tanzânia. O excesso de amônio na solução nutritiva também foi responsável pela área foliar e menor massa de parte aérea e de raízes. Elevadas concentração de MDA e peróxido foram encontrados nos componentes da parte aérea de plantas crescidas sob doses de nitrogênio com proporção de NO3-/NH4+ de 40/60, indicando estresse oxidativo nessas plantas. O estresse ocasionado pelo fornecimento exclusivo da forma nítrica ou pelo excesso de amônio resultou na indução de uma nova banda de SOD no sistema radicular do capim tanzânia, o que sugere que essa enzima tenha sido mais responsiva na eliminação de EROs no sistema radicular. / Nitrogen is one of the nutrients that most improve forage grass productivity and the forms of this nutrient supply may affect plant responses. The objectives were to evaluate morphogenic, nutritional, metabolic and productive changes in tanzânia guineagrass (Panicum maximum cv. Tanzânia), as realated to the supply of nitrogen rates and NO3-/NH4+ proportions in the nutrient solution. The experiment was carried out in a greenhouse, by an inert substrate and testing three nitrogen rates to supply low, intermediate and hight nitrogen nutrition and three NO3-/NH4+ proportions (100/0, 70/30, 40/60) to have no ammonium up to relative excess ammonium. Plants had shoots harvested two times and roots were collected after the second harvest. Plant evaluations included number of leaves and tillers, leaf and tiller appearance rates, leaf area, shoots and roots dry matter production, plant tissue concentrations of total nitrogen, nitrate and ammonium, SPAD value, concentrations of malondialdehyde and hydrogen peroxide, and activities of the enzymes nitrate reductase, glutamine synthase, catalase, superoxide dismutase and glutatione reductase. Low nitrogen dose damaged the leaf area and dry matter production in both growths of tanzânia grass. The excess of ammonium in the nutrient solution was also responsible for leaf area and lower mass of shoots and roots. High concentration of MDA and peroxide were found in the shoot components of grown plants under nitrogen levels ratio of NO3-/NH4+ 40/60, indicating oxidative stress in these plants. The stress caused by the exclusive supply of the ammonium nitrate form, or excess of ammonium resulted in the induction of a new band of SOD on the root system of the tanzânia guineagrass, suggesting that this enzyme has been more responsive in the elimination of ROS in the root system.

Gesteigerter oxidativer Stress ist ein typisches Zeichen in der Pathogenese der Herzinsuffi-zienz. Anhand von 2 Rattenmodellen sollen charakteristische Veränderungen des enzymatischen antioxidativen Systems, repräsentiert durch die Glutathionperoxidase (GSH-Px) und Superoxiddismutase (SOD) sowie Änderungen im Hitzeschockproteinsystem (Hsp) untersucht werden, für das stellvertretend Hsp25 und Hsp72 bestimmt wurden. Daneben wurde die Lipidperoxidation durch die Konzentration von Thiobarbitursäure-reaktiven Substanzen (TBARS) quantifiziert. Im ersten Rattenmodell, der Hypertonie-induzierten Herzinsuffizienz durch permanente Renin-Angiotensin-System-Aktivierung in doppelt transgenen Ratten konnte eine linksventrikuläre Hypertrophie mit CK-Isoenzym-Shift mit vermehrter Expression von CK-MB und -BB beobachtet werden. Es kam in beiden Ventrikeln der transgenen Tiere zu einer Zunahme der Lipidperoxidation begleitet von einer Erniedrigung der Serum-Vitamin E-Konzentration durch Verbrauch. SOD und Hsp72 blieben unverändert. Durch die biventrikuläre Zunahme der GSH-Px-Aktivität bei linksventrikulär erhöhtem Hsp25-Gehalt konnte die Toleranz gegenüber Hypoxie/Reoxygenierungsstress erhöht werden. In der 2. Teilstudie - der Myokardinfarkt-induzierten Herzinsuffizienz - wurden die Parameter oxidativer Schädigung und antioxidativen Schutzes im Akutstadium (14-16h) und 3, 6 und 9 Wochen nach experimentellem Infarkt (MI) bestimmt. In der Akutphase zeigten sich in beiden Ventri-keln und im Papillarmuskel gesteigerte GSH-Px- und SOD-Aktivitäten, ohne dass kardiale Hypertrophie vorlag. Hsp72 und Hsp25 waren während der Akutphase nach MI im Papillar-muskel und im linken Ventrikel erhöht. In der Folge resultiert eine verbesserte kontraktile Funktion bei experimentellem Hypoxie/Reoxygenierungsstress. Damit gelang es erstmals eine Selbstprotektion des Myokards während eines akuten MI nachzuweisen. Erst ab der 6. Woche trat kardiale Hypertrophie auf, begleitet vom charakteristischen CK-Isoenzym-Shift. Während die SOD und die Hitzeschockproteine nach der akuten Phase auf das Niveau der Kontrollen absanken, blieb die hohe GSH-Px-Aktivität im linken Ventrikel über den gesamten Untersuchungszeitraum bestehen, bei zunehmender Toleranz des Herzens gegenüber Hypoxie/Reoxygenierungsstress. Die vorgelegten tierexperimentellen Untersuchungen zeigen, dass das Herz sowohl unter akut als auch unter chronisch gesteigertem oxidativen Stress Mechanismen zur Selbstprotektion aktivieren kann, die eine Prävention bzw. Minimierung von Schädigungsreaktionen durch Sauerstoffradikale ermöglichen. / Elevated oxidative stress is typical in the pathogenesis of heart failure. Characteristical changes in antioxidant enzyme status, represented by glutathionperoxidase (GSH-Px) and superoxide dismutase (SOD), and changes in heat shock protein status (Hsp), denoted by Hsp25 and Hsp72, have been revealed in two different rat-models. Lipidperoxidation was quantified by the concentration of thiobarbituric acid reactive substances (TBARS). In the first model of heart failure caused by permanent activation of renin-angiotensin system in double transgenic rat, leftventricular hypertrophy accompanied by a shift of creatine kinase (CK) isoenzyme pattern to higher concentration of fetale CK-MB an -BB-isoforms was found. Higher TBARS concentrations and lower alpha-tocopherol levels caused by consumption have been measured. SOD and Hsp72 remained unchanged. The tolerance against experimental hypoxia/reoxygenation was improved by higher levels of GSH-Px and Hsp25 in both right and left ventricular tissue. In the second study of heart failure caused by experimental myocardial infarction (MI) the parameters of oxidant demolishing and antioxidant defence were evaluated under acute condi-tions (14-16h) and 3, 6 and 9 weeks after infarction. In the acute period higher activities of GSH-Px and SOD in non-hypertrophied left and right ventricular tissue and papillary muscle have been reported. Leftventricular and papillary muscle Hsp25 and Hsp72 content showed higher levels 14-16 hours after MI compared with controls, improving the contractile function in hypoxia/reoxygenation experiments. These findings suggest for the first time a myocardial self-protection after acute myocardial infarction. 6 and 9 weeks after MI leftventricular hyper-trophy occurred attended by the characteristic CK-isoenzymeshift. While SOD-activity and Hsp-content decreased to the levels of the controls, GSH-Px remained on higher altitude in leftventricular tissue in all examined periods after MI. This was accompanied by better toler-ance against hypoxia/reoxygenation stress. These findings of experimental-induced heart failure show the activation of myocardial self protecting mechanisms under acute and chronic oxidative stress conditions, minimizing or even preventing demolishing reactions of oxygen radicals.

Made available in DSpace on 2017-07-21T20:00:00Z (GMT). No. of bitstreams: 1 Lilian Prione.pdf: 1165937 bytes, checksum: d73d6916708640fa9af6db139db8b8c2 (MD5) Previous issue date: 2014-02-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Herbicides are widely used to increase crop production and account for 35% of all agrochemicals applied annually. After application, the herbicides can remain in the soil as hazardous residues. Mesotrione, (2-[4-methylsulfonyl-2-nitrobenzoyl]1,3-cyclohenanedione), is the active ingredient of Callisto, an herbicide commonly used in corn. Pantoea ananatis CCT 7673, an Enterobacteria isolated from water, has been previously cited as mesotrione-degrading strain. The aim of this study was to evaluate the influence of mesotrione and Callisto as oxidative stress-inducing agents for cellular metabolism of Pantoea ananatis CCT7673 and identify possible mechanisms of tolerance. SOD, CAT and GR activities were evaluated in non-denaturing PAGE and CAT, GR and GST in spectrophotometer. Also, the rates of malonaldehyde (MDA), superoxid and peroxide hydrogen (H2O2) were measured in a spectrophotometer. Minimal medium with no herbicide (MM) was used as control. Lipid peroxidation, superoxide and peroxide hydrogen quantification and SOD, CAT, GR and GST activities were analyzed before and after degradation of mesotrione. The herbicide proved to be the cause of oxidative stress, according to peroxide hydrogen data. Unexpectedly, the rates of lipid peroxidation (MDA) and GR showed to be lower in the presence of the herbicide when compared to the control, with no changes in bacterial growth. The activity of GST was higher in mesotrione treatment in comparison to control and Callisto, during and after degradation. These results suggest that this enzyme may be related to the mesotrione degradation, probably by cometabolism. The rates of lipid peroxidation were shown to be lower in the presence of the herbicide compared to the control, with no changes in growth rates when exposed to herbicide. P. ananatis CCT 7673 showed changes in the saturation of membrane lipids. These changes may interfere with herbicide entry into the cell. These characteristics may be associated with a level of phenotypic plasticity in P. ananatis CCT 7673, making this an interesting bacterium for studies of herbicide tolerance and evolution of microbiota in environments subjected to different degrees of selective pressure model. / Herbicidas são amplamente utilizados para aumentar a produção agrícola e são responsáveis por 35% de todos os agrotóxicos aplicados anualmente. Após a aplicação, os herbicidas podem permanecer no solo como resíduos perigosos. O mesotrione (2 - [ 4 - metilsulfonil - 2 - nitrobenzoil ] 1,3- cyclohenanedione ) é o ingrediente ativo de Callisto, um herbicida utilizado no milho . Pantoea ananatis CCT 7673, é uma enterobactéria isolada de água e foi previamente caracterizada como linhagem degradadora do mesotrione. Os objetivos deste trabalho foram o avaliar a influência do mesotrione e Callisto como agentes indutores de estresse oxidativo para o metabolismo celular de Pantoea ananatis CCT7673, bem como identificar possíveis mecanismos de tolerância a estes herbicidas. As atividades enzimáticas de SOD, CAT e GR foram avaliadas em PAGE não desnaturante e de CAT, GR e GST em espectrofotômetro. Além disto, as taxas de malondialdeído (MDA), radical superóxido e peróxido de hidrogênio (H2O2) foram medidas em espectrofotômetro. Todas as análises foram realizadas antes e após a degradação do mesotrione. Meio mínimo sem herbicida (MM) foi utilizado como controle. O herbicida provou ser agente causal do estresse oxidativo pelos dados de peróxido de hidrogênio. Inesperadamente, as taxas de MDA e GR mostraram-se inferiores nos tratamentos com herbicida em relação ao controle, sem alteração no crecimento bacteriano. A atividade de glutationa-S-transferase foi maior no tratamento com mesotrione em comparação com o controle e Callisto, durante e após a degradação. Estes resultados sugerem que essa enzima pode estar relacionada com o processo de degradação do mesotrione, provavelmente por cometabolismo. As taxas de peroxidação lipídica mostraram ser menores na presença do herbicida em comparação com o controle, sem mudanças na taxa de crescimento Quando exposta ao herbicida, P. ananatis CCT 7673 apresentou alterações na saturação de lipídios de membrana. Estas mudanças podem interferir na entrada do herbicida na célula. Tais características podem estar associadas a um nível de plasticidade fenotípica em P. ananatis CCT 7673, tornando essa bactéria um modelo interessante para estudos de tolerância a herbicidas e evolução de microbiotas em ambientes submetidos a diferentes graus de pressão seletiva.