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Caracterização molecular e bioquímica de uma esterase macho-específica em Zaprionus indianus /Paulino, Rafael Marques January 2008 (has links)
Resumo: Zaprionus indianus (Diptera:Drosophilidae) é uma espécie provavelmente de origem africana e que rapidamente se dispersou por parte do continente sul-americano. Hoje, indivíduos dessa espécie são encontrados numa amplitude latitudinal de 35°, do Uruguai a Belém (Brasil). Em Z. indianus e nos demais insetos, as esterases constituem um grupo multifuncional e heterogêneo de enzimas que participam da hidrólise de ésteres, além de estarem relacionadas a diversos processos metabólicos. Neste estudo, foram realizadas análises de esterases de Z. indianus e Drosophila melanogaster, em géis de poliacrilamida (PAGE) a 10% de concentração, em indivíduos dos dois sexos e em diferentes fases do desenvolvimento. Os resultados indicaram que algumas carboxilesterases (respectivamente EST-2 e EST-5 de Z. indianus e EST-6 D. melanogaster) apresentam atividade acentuada em machos. Estas enzimas mostraram similaridades nas duas espécies, tais como o mesmo padrão de inibição, expressão principalmente no estágio adulto e aumento da atividade enzimática com o aumento da idade dos indivíduos. As similaridades bioquímicas entre as enzimas dos dois drosofilídeos sugerem ortologia entre seus genes codificadores. Foram então realizadas reações de PCR, utilizando oligonucleotídeos iniciadores desenhados com base na seqüência do gene Est-6 de D. melanogaster e o DNA genômico de Z. indianus. O fragmento amplificado foi seqüenciado, com composição GC de 48,5% e similaridade de 73% com a seqüência do gene de Est-6 de D. melanogaster. A análise da razão das substituições sinônimas e não sinônimas sugere uma proteína sob ação de seleção normalizadora, onde as trocas sinônimas são em sua maioria neutras e as não sinônimas, na maioria das vezes deletérias, foram eliminadas pela seleção natural. A modelagem ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Zaprionus indianus has expanded its geographical distribution since its recent invasion of the South American continent. The first record data of only eight years, and the origin is probably the South Africa. Nowadays, this species can be found in a latitudinal range of 35º, from Uruguay to Belem (Brazil). Esterases comprise a multi-functional and heterogeneous group of enzymes that participated in ester hydrolysis. In insects, they are related to several metabolic processes, including the reproductive function. Esterase patterns in Z. indianus and Drosophila melanogaster were characterized in polyacrylamide gels (PAGE). Two - esterases from Z. indianus, EST-2 and EST-5, showed similarity preference for substrate - naftil acetate and patterns of inhibition as compared to the EST-6 of D. melanogaster, suggesting a possible role in reproductive biology for both enzymes. Biochemical characterization of these esterases and its differential expression in males, suggest orthology among their genes. In this work, the genomic DNA from Z. indianus was submitted to PCR experiments using 3 sets of D. melanogaster Est-6 sequence primers. The PCR products were directly sequenced; its GC content was 48.5% and presented a 73% similarity compared to Est-6 D. melanogaster sequence. Analysis of sequence data, by estimates of nonsynonymous/synonymous rate ratios, showed that the majority of sites evolves under strong or moderate negative selection (81%) and a minority of sites (19%). is under significant positive selection. Molecular modeling indicates that the fundamental structural features important for catalysis are conserved in the esterase of Z. indianus and human bilesalt activated lipase (BAL), which was used as structural model. Structural and sequence comparisons suggest the evolutionary relationship between ...(Complete abstract click electronic access below) / Orientador: Carlos Roberto Ceron / Coorientador: Claudia Marcia Aparecida Carareto / Banca: Maura Helena Manfrin / Banca: Hermione de Campos Bicudo / Mestre
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Isolamento e caracterização do gene da esterase relacionado a resistencia a inseticidas organofosforados na mosca praga da pecuaria Cochliomyia hominivorax (Diptera: Calliphoridae) / Isolation and characterization of esterase gene related with OP insecticide resistance in Cochiliomya Hominivorax (Diptera: Calliphoridae)Carvalho, Renato Assis de 22 March 2007 (has links)
Orientador: Ana Maria Lima de Azeredo-Espin / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T11:52:20Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007 / Resumo: A pecuária bovina tem significativa importância no contexto sócio-econômico para o país, sendo responsável pela produção anual de mais de 2 milhões de toneladas de carne, uma das principais fontes de proteína animal da dieta do consumidor brasileiro. A alta produtividade deve estar sempre acompanhada de um controle sanitário eficiente desses animais. Os prejuízos econômicos provocados por ecto e endoparasitas estão entre os principais fatores limitantes da produção animal. Dentre os ectoparasitas de maior importância na pecuária nacional e considerada uma das principais pragas, está a Cochliomyia hominivorax (Coquerel), conhecida no Brasil como a mosca da bicheira. Os prejuízos causados pelas infestações dessa espécie vêm através da redução da qualidade do couro e da produção de leite, na perda de peso e fertilidade do hospedeiro, e mortalidade dos animais infestados. No Brasil, o seu controle tem sido realizado principalmente através da aplicação de inseticidas organofosforados (OP). Porém, o uso indevido e/ou prolongado desses agentes químicos pode provocar a seleção de indivíduos resistentes. Com a recém introdução de outros princípios ativos, como os piretróides, nas formulações dos inseticidas para controle da C. hominivorax, associada ao fato de que a espécie L. cuprina (Calliphoridae), causadora de miíases em ovelhas, adquiriu resistência ao inseticida OP em menos de 10 anos de uso de tal inseticida, torna-se evidente a importância da investigação da resistência a inseticidas OP em C. hominivorax. Através da amplificação heteróloga com 'primers¿ previamente construídos para L. cuprina, e com 'primers¿ construídos especificamente para C. hominivorax, o gene da esterase E3 foi amplificado e seqüenciado nesta espécie. Foram identificadas as mesmas mutações (Gly137/Asp e Trp251/Ser) responsáveis por conferir resistência a inseticidas organofosforados em L. cuprina e Musca domestica. Além da caracterização dessas mutações, foi desenvolvido um método rápido e eficiente para identificação da principal mutação relacionada com resistência a OP. Toda a região codificante da carboxilesterase E3 foi amplificada e seqüenciada em C. hominivorax, permitindo sua caracterização nesta espécie. Através da realização de um bioensaio utilizando inseticidas organofosforados, a principal mutação (Gly137/Asp) foi associada com a resistência a tal classe de inseticidas em C. hominivorax. A caracterização deste gene nas populações naturais da mosca da bicheira permitirá a realização de uma análise da freqüência de indivíduos resistentes nas diferentes regiões do Brasil, o que possibilitará o uso mais apropriado e eficiente dos agentes químicos nas propriedades com atividade pecuária, contribuindo para uma maior produtividade animal e menor dano ambiental / Abstract: The cattle breeding is very important to the social-economic context of Brazil. It is responsible for annual production of more than 2 million ton of meat, one of the essential sources of animal protein on Brazilian diet. The large productivity should be always accomplished by an efficient sanitary control of the animals. The economic losses caused by internal and external parasites are the main limiting factors of meat production. Cochliomyia hominivorax (Calliphoridae) is one of the most important myiasis-causing flies and it is responsible for severe economic losses, mainly by reducing the quality of leather and the production of milk and meat. In Brazil, C. hominivorax has been controlled by applying insecticides, particularly organophosphate (OP)-based compounds. However, the improper and continuous use of these chemicals can lead to the selection of OP-resistant strains. Changes in a specific carboxylesterase (E3) activity have been associated with OP resistance in Lucilia cuprina, one important myiasis-causing fly in sheep in Australia and also a member of the Calliphoridae family. The recent introduction of other insecticides for C. hominivorax control, associated with the development of OP resistance in L. cuprina in less than ten years, shows the importance of resistance investigation in C. hominivorax. Based on foregoing studies, the same mutations responsible for conferring OP resistance in L. cuprina and Musca domestica (Muscidae) were identified in C. hominivorax. Besides characterization of these mutations, a rapid and efficient method for identifying the major mutation related to OP resistance (Gly137/Asp) was developed. Moreover, the entire codifying region of carboxylesterase E3 was amplified and sequenced, allowing its characterization in this species. Using a bioassay, the major mutation (Gly137/Asp) was associated with OP resistance in C. hominivorax. The characterization of this gene in natural populations can be an important tool for surveying resistance to insecticides in different regions of Brazil. This will provide information for the selection and for the implementation of more effective pest management programs / Mestrado / Genetica Animal e Evolução / Mestre em Genética e Biologia Molecular
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Cloning, expression and characterization of Novel Lipase and Esterases from Burkholderia multivorans UWC10Rashamuse, Konanani J January 2005 (has links)
Doctor Scientiae / An esterase and lipase producing Burkholderia multivorans strain was isolated by culture enrichment strategies. A shotgun library of Burkholderia multivorans genomic DNA (prepared in E. coli/pUC18) was screened for lipase and esterase activities. Three positive recombinant clones, pTEND5, pHOLA6 and pRASHI4, conferring esterolytic and lipolytic phenotypes respectively, were identified. Full-length sequencing of DNA inserts was performed using subeloning and "primer-walking" strategies. Nucleotide sequence analysis revealed that the pRASH14 plasmid DNA consisted of two open reading frames (ORPI and ORP2) encoding 356 and 350 amino acids, respectively. Database searches revealed that ORPI and ORP2 were homologous to lipases and chaperones from subfamily I.2. In the pTEND5 sequence, an open reading frame consisting of 978 bp, encoding 326 amino acids, was identified. Database searches revealed that this open reading frame was homologous to family Vesterases. Nucleotide sequence analysis revealed that pHOLA6, plasmid DNA consisted of 1194 bp encoding 398 amino acids and showed homology to family VIII esterases. The primary structures of LipA, EstEFH5 and EstBL from pRASHI4, pTEND5 and pHOLA6, respectively, showed a classical GxSxG motif, which is conserved in many serine hydrolases. In addition, EstBL also showed a consensus SxxK motif, the serine of which acts as a catalytic nucleophile in class C B-lactames and some peptidases.
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Structural, Enzymatic, and Inhibitory Studies of Two Mycobacterium tuberculosis- Mycomembrane Lipid EsterasesGoins, Christopher M. 21 December 2018 (has links)
No description available.
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Functional diversity in nutrient acquisition by ectomycorrhizal fungi /Nygren, Cajsa, January 2008 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet,2008. / Härtill 4 uppsatser.
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BIOCHEMICAL AND TOXICOLOGICAL IMPACT OF INSECTICIDE SYNERGISTS ON THE HONEY BEE APIS MELLIFERA L.TODESCHINI, VALERIA 31 May 2017 (has links)
Il sinergizzante piperonil-butossido (PBO) usato in combinazione con insetticidi è in grado di contrastare i parassiti resistenti inibendo temporaneamente i sistemi di detossificazione. Nuovi sinergizzanti sono stati sintetizzati a partire dalla struttura molecolare del PBO, ma anche gli insetti utili come le api possono risentire di una maggiore efficacia degli insetticidi.
In questo studio abbiamo osservato l’attività enzimatica in vitro (esterasi, acetilcolinesterasi, glutatione S-transferasi e monossigenasi P450) di api operaie Italiane e Carniche in presenza del PBO e dei suoi nuovi derivati del benzodiossolo e 2,3-diidrobenzofurano mediante saggi spettrofotometrici, per determinare se i sistemi di detossificazione e altri sistemi enzimatici sono influenzati dai sinergizzanti.
I nuovi derivati del PBO possono inibire parzialmente le esterasi in alcune popolazioni di api più sensibili.
Altri sistemi enzimatici non sembrano essere inibiti dai sinergizzanti studiati.
Studi di tossicità acuta orale e di contatto sono stati condotti in laboratorio presso il Bee Research Institute (Dol, Repubblica Ceca) su api operaie Carniche per verificare il possibile incremento di tossicità degli insetticidi imidacloprid e alfa-cipermetrina in combinazione con PBO e i suoi derivati del benzodiossolo.
Gli studi hanno mostrato una differenza significativa tra la tossicità dei due principi attivi da soli e in combinazione con i sinergizzanti. / The synergist piperonyl-butoxide (PBO) has been proved to successfully control resistant pests when combined with insecticides by temporarily inhibiting the detoxification systems which lead to resistance. New synergists, starting from the molecular structure of PBO, have been developed but pollinators may also suffer from an increased efficacy of insecticides.
In this study we observed in vitro enzyme (esterases, acetylcholinesterases, glutathione S-transferases and P450 mixed function oxidases) activity of Italian and Carniolan honey bee workers in presence of the synergist PBO and its novel benzodioxole and 2,3-dihydrobenzofuran derivatives through spectrophotometric assays, to determine if detoxification systems and other enzymatic systems are affected by synergists.
This data show that novel PBO derivatives may partially inhibit esterases in some honey bee populations which are more sensitive.
Other enzymatic systems seem not to be targeted by the studied synergists.
Acute oral and contact toxicity studies were conducted in laboratory conditions at the Bee Research Institute (Dol, Czech Republic) on adult Carniolan workers to investigate the possible increase of imidacloprid and alpha-cypermethrin toxicity when combined with PBO and its benzodioxole derivatives.
Tests showed some significant difference between the toxicity of the two active principles alone and combined with the synergists.
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Efeito da Hidroxiuréia, uma substância de uso médico, sobre parâmetros biológicos de Drosophila melanogaster /Rangel, Veronica Ferreira. January 2011 (has links)
Orientador: Hermione Elly Melara de Campos Bicudo / Banca: Otávio Ricci Júnior / Banca: Cláudia Regina Bonini Domingos / Resumo: A Hidroxiuréia (HU) é utilizada como medicamento em várias doenças humanas, incluindo anemia falciforme e câncer. Basicamente, na primeira, atua aumentando a porcentagem de hemoglobina fetal, o que diminui a gravidade do quadro clínico por inibir a polimerização da hemoglobina S e, no segundo, atua impedindo a síntese de DNA na fase S, desta forma bloqueando a divisão celular. Há preocupação com o tratamento longo com essa substância por causar efeitos colaterais, um dos quais se relaciona a problemas na fertilidade masculina. A Drosophila, devido a várias características, como ser o organismo com maior homologia com o homem quanto às doenças genéticas, por utilizar esses genes homólogos nos mesmos processos, mas de forma simplificada e por expressar os genes humanos em construções transgênicas, é hoje muito utilizada em estudos de doenças humanas e de respostas a fármacos, buscando esclarecer mecanismos de ação e conseqüências do uso. Neste trabalho, foram estudados, sob o efeito da HU em duas concentrações (0,1 e 0,25mg/ml de meio de cultura), no modelo biológico mencionado, as características taxa de oviposição, produtividade (número de descendentes), tempo de desenvolvimento, mortalidade, longevidade, tempo de pré-cópula , duração da cópula, presença de alterações morfológicas externas, morfologia do aparelho reprodutor masculino, modificações do peso das moscas, morfologia dos cromossomos politênicos e padrão de expressão das enzimas esterasicas. A produtividade foi analisada em seis gerações consecutivas, visando obter maior compreensão dos efeitos da HU. Cada característica analisada envolveu uma metodologia diferente, descrita no corpo do trabalho. A análise estatística foi baseada na aplicação da ANOVA, e nas comparações de Kruskal-Wallis e Mann-Whitney. Em algumas características o efeito do tratamento mostrou-se... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hydroxyurea (HU) is used as a medicine in several human diseases, including sickle cell disease (SCD) and cancer. Basically, in the first, HU acts by increasing the percentage of fetal hemoglobin, thus decreasing the severity of the disease symptoms due to inhibition of the hemoglobin S polymerization. In the second mentioned disease, it acts by preventing DNA synthesis in S phase, thereby blocking cell division. There is some concern about side effects caused by the long-term treatment with HU. One of them relates to problems in male fertility. Drosophila, because of its characteristics, such as being the organism with the highest homologies with man as to genetic diseases, since it uses homologous genes in these processes in a simplified form, and also by expressing human genes in transgenic constructs, is now being widely used in studies of human diseases and responses to drugs, seeking for clarifying action mechanisms and consequences of their use. In this work, we studied, in Drosophila biological characteristics under the effect of HU in two concentrations (0.1 and 0.25 mg / ml of culture medium), including oviposition rate, productivity (number of offspring), time development, mortality, longevity, pre-mating and mating duration, presence of morphological changes in external morphology and in the male reproductive system, fly weight changes, polytene chromosome morphology and patterns of esterase enzymes. Productivity was analyzed in six consecutive generations. Each feature analyzed involved a different methodology, described in the body of the work. Statistical analysis was based on the application of ANOVA, and comparisons using the Kruskal-Wallis and Mann-Whitney tests. In some characteristics, the effect of treatment was dosisdependent. In the light of numbers, productivity was higher in control experiments (C) of six generations, and among the treated ones with... (Complete abstract click electronic access below) / Mestre
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Triagem de enzimas associadas à biotransformação de hidrocarbonetos a partir de metagenoma de sedimentos contaminados com petroléo e metais pesados / Screening of Enzymes Related to Biotransformation of Hydrocarbons from Metagenome of Contaminated Sediments with Oil and Heavy MetalsSimões, Tiago Henrique Nogueira 08 July 2009 (has links)
A metagenômica trouxe novas perspectivas ao estudo de comunidades microbianas no ambiente, permitindo explorar tanto a diversidade taxonômica de microrganismos ainda não-cultivados, como o acesso direto a genes e vias metabólicas. Neste trabalho, foram construídas bibliotecas metagenômicas a partir de amostras de sedimentos de mangue da Baía de Guanabara (RJ), impactadas com hidrocarbonetos de petróleo e metais pesados. Proteobacteria (33,3%), bactérias afiliadas a redutoras-de-sulfato (29,7%) e Firmicutes (20%) representaram os grupos principais nas amostras ambientais, baseado em análises filogenéticas de rDNA 16S, ao passo que isolamentos seletivos utilizando diesel e naftaleno permitiram a recuperação preferencial de delta-Proteobacteria e actinomicetos. Bibliotecas metagenômicas dos sedimentos enriquecidos com óleo diesel, com insertos entre 25 e 35 Kb clonados em fosmídeos, foram triadas para detecção de genes catabólicos de monoxigenases (alkB1) e expressão de epóxido-hidrolases, esterases, lipases e monoxigenases em ensaios de alto desempenho (HTS, high throughput screening). Clones reativos a alkB1 foram detectados, porém não foram funcionais nas condições de HTS testadas. Nas bibliotecas de fosmídeos triadas, vários clones apresentaram atividade enzimática, sendo que dois apresentaram atividade de lipase-esterase com alta seletividade, elevada taxa de conversão de substratos e excesso enantiomérico (ee >99%). Os resultados de HTS comprovaram a eficiência do uso da clonagem direta de DNA ambiental na expressão de vias metabólicas de interesse com potencial de aplicação biotecnológica. / Metagenomics brought a new perspective to the study of microbial communities in the environment, enabling access to the taxonomic diversity of uncultured microorganisms, as well as direct access to genes and metabolic pathways. In the current study, metagenomic libraries were constructed from mangrove sediment samples of the Guanabara Bay (RJ, Brazil), impacted with oil hydrocarbons and heavy metals. Proteobacteria (33.3%), sulfate-reducing affiliated bacteria (29.7%) and Firmicutes (20%) represented the main groups in the environmental samples based upon 16S rDNA phylogenetic analysis, whereas selective isolation using diesel and naphtalene yielded delta-Proteobacteria and actinomycetes. Metagenomic libraries of diesel-enriched sediment samples, with 25 to 35 Kb fosmid inserts, were screened for detecting monooxigenase genes (alkB1) and expression of epoxide hydrolases, esterases, lipases and monooxigenases in high throughput screening (HTS) assays. Clones reactive to the alkB1 probe were detected, but were not functional under the HTS conditions used. Several functional clones were detected in the clone library, and two showed lipase-esterase activity with high rates of substrate conversion and enantiomeric ratio (ee >99%). The results obtained on HTS showed the efficiency of the direct cloning of environmental DNA for the expression of metabolic pathways with potential biotechnological application.
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Studies On The Mechanism Of Resistance Against Pyrethroids In Helicoverpa Armigera: Molecular And Proteomic ApproachKonus, Metin 01 September 2012 (has links) (PDF)
Helicoverpa armigera is an insect, causes important economical losses in crops. To reduce this loss, chemical insecticides such as pyrethroids have been commonly used against H. armigera in farming areas all over the world. However, excess and continuous usages of them cause resistance development in H. armigera. Insects develop resistance against applied insecticides by following three main mechanisms / by reducing the amount of insecticide entering into the insect body, developing insensitivity of the insecticide effective site and increasing detoxification metabolism of insecticides such as increased metabolism of them in midgut tissue of H. armigera. Therefore, changes in differentially expressed midgut proteins were analysed at protein level with two-dimensional gel electrophoresis (2D-PAGE) and matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) together with examine biochemical activity changes of certain detoxification enzymes such as esterases (EST) and glutathione S-transferases (GST). Moreover, transcriptional level analysis of certain genes from EST and GST systems together with cytochrome P450 monooxygenases (CYP450) system were done with quantitative real-time PCR method, too.
According to the comparative proteome analysis, it was found that H. armigera field samples overcome pyrethroid stress mainly by increasing energy metabolism related proteins expressions such as ATP synthase, Vacuolar ATPase A and B and arginine kinase proteins. Furthermore, certain detoxification enzymes such as thioredoxin peroxidase and NADPH cytochrome P450 reductase were up-regulated in Mardin population, suggesting that they were actively participating in response to pyrethroid stress. NADPH cytochrome P450 reductase could play a role in detoxification of toxic pyrethroid metabolites such as 3-phenoxybenzaldehyde. However, while glutathione S-transferases (GSTs) were not found up-regulated in the comparative proteome analysis, biochemical assays (GST-CDNB, GST-DCNB and GST-PNBC) showed significant increases in enzyme activities in the Adana and in the Mardin field population, as compared to the susceptible strain. Furthermore, GST-DCNB and GST-PNBC activities showed significant increase in Ç / anakkale population. As overcoming energy crisis may lead to an increase in oxidative stress, detoxification enzymes (GSTs and thioredoxin peroxidase) might be involved in pathways for eliminating toxic reactive oxygen species such as H2O2. Similarly, although esterases (EST) were not found as differentially expressed, biochemical assays for ESTs showed significant increases in enzymatic activities in the Adana and the Mardin field populations. Thus, ESTs are also proposed to be involved in developing resistance as an initiator of pyrethroid metabolism in H. armigera from Turkey.
Quantitative real-time PCR results showed that while CYP9A14 gene expression was up-regulated in all analyzed field populations, CYP9A12 gene expression was up-regulated in both Ç / anakkale and Mardin populations. CYP4S1 gene expression was also up-regulated only in Mardin field population. However, while CYP6B7 gene expression together with CYP9A12 and CYP4S1 genes expressions were down-regulated in Adana population, CYP6B7 gene expression was not significantly changed in both Ç / anakkale and Mardin populations. In addition, GST, GSTX01 and ESTX018 gene expressions were not significantly changed in all field populations in comparison to susceptible population. Therefore, CYP9A14, CYP9A12 and CYP4S1 genes proposed to be involved in detoxification of toxic pyrethroid metabolites possibly through regulation of NADPH cytochrome P450 reductase.
In conclusion, it is suggested that one of the main mechanisms of resistance development is increased energy metabolism in the midgut tissue of H. armigera which may be a general prerequisite for compensating the costs of energy-consuming detoxification processes.
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Impact of green manure on soil organisms : with emphasis on microbial community composition and function /Elfstrand, Sara, January 2007 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2007. / Härtill 4 uppsatser.
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