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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avaliação de fungos com potencial de degradação com diuron e pyrithiobac-sodium

Tomaz, Rose Marry Araujo Gondim 18 December 2003 (has links)
Orientadores: Telma Teixeira Franco, Lucia Regina Durrant / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-03T21:02:47Z (GMT). No. of bitstreams: 1 Tomaz_RoseMarryAraujoGondim_D.pdf: 4644251 bytes, checksum: 70dfbe58b4071cd1f724a85ce480e652 (MD5) Previous issue date: 2003 / Resumo: Inicialmente, foi desenvolvido experimento em casa-de-vegetação com dois tipos de solo, arenoso e argiloso, com o objetivo de avaliar o efeito dos herbicidas diuron e pyrithiobacsodium-sodium na microbiota do solo. Doses de diuron e pyrithiobac-sodium de O, 1, 2, 4 e 8 vezes a dose recomendada para o campo foram aplicadas sobre plantas de algodão, cv IAC 23. Amostras de solos foram coletadas periodicamente para levantamento das populações de fungos, bactérias e actinomicetos, determinação do pH e seleção de fungos no solo com a mais alta dose dos herbicidas. Houve diferença entre a biota dos solos para ambos os herbicidas. A população de fungos e bactérias diminuiu com o acréscimo das doses aplicadas a de actinomicetos aumentou para o solo argiloso e reduziu para o arenoso quando se utilizou o diuron. Para o pyrithiobac-sodium ocorreu aumento da população de fungos, redução do número de bactérias e, em relação aos actinomicetos, a população diminuiu no solo arenoso com o aumento das doses. No solo argiloso, apenas na dose recomendada apresentou crescimento de actinomicetos, havendo redução com as demais doses. Os 106 fungos isolados foram utilizados em experimentos para seleção delinhagens resistentes a concentrações elevadas dos herbicidas, utilizando meio sólido suplementado com concentrações crescentes dos herbicidas especificados. Em paralelo, realizou-se a seleção com 24 linhagens de fungos basidiomicetos utilizando, também, meio sólido com elevadas doses dos herbicidas como fonte de carbono. No total, trezefungos foram selecionados (Pleurotus sp (BCCB 507), Pleurotus sp (CCB 068), Pleurotus sp 016, Agarucu.s campestris, Phanerochaete chrysosportum ATCC 24725 e os isolados de solo DP24e, DP240, DRPO2n, DRP02e, SPI6a, SRPI7g, SRP17c e SRP20e). Esses fungos foram incubados em meio liquido de minerais por três dias. Após os três dias, adicionouse 25 pg.mL-l de diuron ou 10 pg.mL-l de pyrithiobac-sodium ao frasco de cultura e incubou-se por 14 dias. As atividades ligninoliticas e porcentagem de degradação foram analisadas, quando se utilizou diuron como fonte de carbono, as linhagens Pleurotus sp (CCB 068) (85,63%), Pleurotus sp (BCCB 507) (64,30%), Pleurotus sp 016 (62,06%) e os isolados de solo SRP17c (71,08%), SRP17g (69,42%), e SRP20e (66,38%) apresentaram as mais altas porcentagens de degradação. Manganês-peroxidase foi a enzima predominante produzida por todas as linhagens. Quando se utilizou pyrithiobac-sodium, somente três linhagens foram capazes de degradá-lo: Pleurotus sp (CCB 068) (61,35%), Agaricus Campestris (37,86%) e Pleurotus sp (BCCB 507) (16,10%). A MnP foi também a enzima predominante. Considerando ambos os herbicidas, a linhagem Pleurotus sp (CCB 068) foi a melhor de todas as testadas. É importante mencionar que as mais altas atividades enzimáticas foram produzidas por essa linhagem, independentemente do herbicida. Com os resultados de degradação e de atividade enzimática mais expressivos, foram selecionadas quatro linhagens: Pleurotus sp (BCCB 507), SRP17 c, Pleurotus sp (CCB 068) e Ag. Campestris; nas três primeiras se utilizou diuron como fonte de carbono; e nas duas últimas, pyrithiobac-sodium. Esses fungos cresceram em concentrações diferentes de diuron (25 pg.mL-l e 35 pg.mL-l) e pyrithiobac-sodium (10 pg.mL-l 20 pg.mL-l), sendo incubados por 30 dias, determinando-se também a porcentagem de degradação. Quando se utilizou diuron, a mais alta porcentagem de degradação foi obtida no sobrenadante da linhagem SRP17c (35 pg.mL-l) (84,74%), seguida da linhagem SRP17c (25 pg.mL-l) (73,46%) e Pleurotus sp (CCB 068) (35 pg.mL-l) (55,11%). Para o pyrithiobac-sodium, a melhor porcentagem de degradação foi obtida no sobrenadante da linhagem Pleurotus sp (CCB 068) (20 pg.mL-l) (94,61%), seguido da linhagem Pleurotus sp (CCB 068)(10 pg.mL-l) (86,42%) e Ag. Campestris (10 pg.mL-l) (53,36%). De acordo com a identificação realizada para o fungo isolado de solo SRP 17 c, sugere-se que pertença ao gênero Rhizopus / Abstract: Pyrithiobac-sodium is a post-emergence herbicide for early application, registered for broadIeaves control in cotton crops. Diuron is a phenylurea used for weed control on non-crop areas and selectively on crops such as cotton, sugarcane, citrus and pineapple. At present, this herbicide is one of the IDOst used in Brazil. Experiments were carried out in green-house, in order to evaluate the effect of these two compounds on the soil biota. Such compounds were applied in O, 2, 4 and 8 times above the recommended rate, and cotton IAC 23 was used. Cotton was planted in sandy and c1ay soils. Soil samples were collected periodically, until 70 and 135 days after application for pyrithiobac-sodium and diuron, respectively. Counting of fungi, actinomycete and bacteria population was realized, and also sail pH variation and several fungi strains selective1y isolated from sail samples previous1y treated with the higher concentration of diuron and pyrithiobacsodium. The biota showed be different regarding the two soil types. To the sandy soil, the increase of pyrithiobac-sodium rate reduced the actinomycete population. To c1ay soil, on1y the recommended rate increased the number of actinomycete, with reduction for higher rates. In both soils the fungi population increased with the increase of the herbicide rate, occurring the opposite for the bacteria population. For the both of soils treated with diuron, the fungi and bacteria population reduced with the increase of the herbicide rate, and actinomycete population increased in the clay soil and was reduced in the sandy soil. The pH increased gradually during the time in both of the soils studied. A total of 106 strains were isolated, of which 8 were selected for furilier evaluation of potential pesticides degradation on the highest levels of these two compounds: DP24e, DP240, DRPO2n, DRP02e SPI6a, SRP 17c, SRP17g and SRP20e. Twenty-four ligninolytic white rot fungi were also used in the preliminary screen. A solid medium containing 1x, 10x or 100x of the pesticides dos ages indicated for fielding application was used as carbon sources. Five strains were selected: Pleurotus sp BCCB 507, Pleurotus sp CCB 068, Pleurotus sp. 016, Agaricus campestris, Phanerochaete chrysosporium ATCC 24725. These fungi were groWD in liquid medium containing minerais and yeast extract for three days when 25 Jµg mL-1of diuron or 10 Jµg mL-1 of pyrithiobac-sodium were added in the culture flasks, and the cultivators were carried out for up to 14 days. Samples were collected and the supernatants were used for the determination of ligninolytic activities (by spectrophotometric assays) and degradation (by HPLC). When diuron was used, highest degradation were observed by the strains Pleurotus sp CCB 068 (85,63%), Pleurotus sp BCCB 507 (64,30%), Pleurotus sp.016 (62,06%), and the soil-isolated SRP17c (71,08%), SRP17g (69,42%) and SRP20e (66,38%). MnP was the predominant enzyme produced by alI strains. When Pyrithibac-sodium was used for as carbon source in the medium on1y three strains were able to degrade it: Pleurotus. sp. CCB 068 (61,35%),Ag. campestris (37,86%) and Pleurotus sp BCCB 507 (16,105%); MnP was a1so the predominant ligninolytic enzyme produced. A new selection of the best strains was carried out based on the levels of herbicides degradation, and also regarding the ligninolytic activities produced by the fungi. The four strains selected were cultivated for 3,6,9, 12, 15,20,25 and 30 days in the diuron (25 Jµg mL-1 e 35 Jµg roL-I) or pyrithiobac-sodium (10 Jµg mL-1 20 Jµg mL-1). Herbicides degradation measured by HPLC, varied with each strain. Highest degradation of diuron (84,74%) was detected by the strain SRP17c 35 J1g mL-1 followed by strain SRP17c 25 Jµg mL-1 (73,46%) and Pleurotus sp (CCB 068) 35 Jµg mL-1 (55,11%). The greatest degradation ofpiIythiobac-sodium (94,61%) was observed with Pleurotus sp (CCB 068) 20 Jµg mL-1 followed by strain Pleurotus sp (CCB 068) 10 Jµg mL-1(86,42%) and also for Ag. Campestris 10 Jµg roL-1 (53,36%). The strain identification SRP17c suggests that this strain belongs to the Rhizopus Class / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

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