Biologia Vegetal

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http://repositorio.ufes.br/handle/10/17503
Programa de Pós-Graduação em Biologia Vegetal

Centro: CCHN
Telefone: (27) 4009 2588
URL do programa: http://www.biologiavegetal.ufes.br/

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Navegando Biologia Vegetal por Autor "Alves, Fernanda Breda"

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    Efeitos do herbicida clethodim (Poquer®) nas interações alelopáticas entre as linhagens produtoras de toxinas de Microcystis aeruginosa e Raphidiopsis raciborskii: o papel da variação de nitrogênio
    (Universidade Federal do Espírito Santo, 2019-09-06) Alves, Fernanda Breda; Fernandes, Valeria de Oliveira; https://orcid.org/; http://lattes.cnpq.br/2323760323729607; https://orcid.org/0000-0002-5718-1848; http://lattes.cnpq.br/6778333557047744; Batitucci, Maria do Carmo Pimentel; https://orcid.org/0000-0002-3485-4448; http://lattes.cnpq.br/0010148251489155; Araujo, Micheline Kezia Cordeiro de; https://orcid.org/0000-0002-5073-3689; http://lattes.cnpq.br/2411893932416218; Corte, Viviana Borges; https://orcid.org/0000000254886578; http://lattes.cnpq.br/3694434981958328; Lubiana, Karoline Magalhaes Ferreira
    Cyanobacteria are photosynthetic organisms that make up the base of the aquatic food chain. Changes in the physical and chemical conditions of aquatic environments, such as increased nutrients and the presence of agrochemicals, alter the structure and dynamics of phytoplankton. Herbicides contaminate the aquatic environment through surface runoff at high concentrations; these compounds cause oxidative stress, interfere with the normal functioning of enzymes and alter the metabolic profile of microalgae and cyanobacteria. The present study investigated the toxicological and physiological effects of clethodim herbicide, as well as nitrogen variation in allelopathic interactions and toxin production by Microcystis aeruginosa BCCUSP232 and Raphidiopsis raciborskii ITEPA1. Effective concentrations (EC50) after 96 hours of exposure of both strains to clethodim were 192.98 mg / L and 168.73 mg / L for R. raciborskii and M. aeruginosa, respectively. The presence of clethodim significantly increased the total microcystin content of M. aeruginosa. In mixed cultivation M. aeruginosa, presented higher cell density when exposed to clethodim, while the highest density of R. raciborskii was observed when exposed to clethodim with limited nitrogen addition. The total content of microcystins (MCs) in mixed culture was 68% higher in nitrogen-enriched cultures than control. A similar increase in MC content was recorded in M. aeruginosa monocultures treated with R. raciborskii exudate. Total saxitoxin concentration was higher in R. raciborskii mixed cultures simultaneously exposed to high nitrogen and clethodim. The intracellular H2O2 content of M. aeruginosa cultures decreased while in R. raciborskii cultures increased during exposure to nitrogen and clethodim. GST activities in cultures of both strains were higher in the presence of clethodim. Our study revealed that nitrogen enrichment and low clethodim concentration could lead to excessive proliferation of M. aeruginosa and R. raciborskii and cyanotoxin production in aquatic environments
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    Microalgas em sistemas de piscicultura: aspectos ecofisiológicos e aplicações sustentáveis.
    (Universidade Federal do Espírito Santo, 2022-03-09) Militão, Frederico Pacheco; Fernandes, Valeria de Oliveira; https://orcid.org/0000-0002-1968-3927; http://lattes.cnpq.br/2323760323729607; Batitucci, Maria do Carmo Pimentel; http://lattes.cnpq.br/0010148251489155; Almeida, Stefano Zorzal de; http://lattes.cnpq.br/3680096174839424; Alves, Fernanda Breda; Dutra, Jean Carlos Vencioneck
    The present study aims to evaluate the potential of microalgal biomass as a supplement in human and animal nutrition, from species isolated from psiculture tanks. Thus, 10 species, from 9 genera and two different divisions, were selected for biomass increase and laboratory-scale cultivation, isolated from fish farming systems in the Municipality of Registro, São Paulo, Brazil. The cultivation was of the batch type, without direct spraying of CO2, initial pH of 7 ± 0.05 and constant aeration of 3.5 L/min of air. The cultures were performed in quadruplicate in ASM1 (Cyanophyta) and BBM (Chlorophyta) medium, with an initial inoculum of 3.0 x105 Cel/mL-1, with the exception of S. hirsutum, a species with slower growth, which was of 3250 Cell/mL-1. The highest concentrations of total soluble carbohydrates, at the end of the experiment, were found in Chlorococcum sp. (12 mg/g MS), Kirchneriella sp. (11.3 mg/g MS) and M. wesenbergii (11.3 mg/g MS). Chlorococcum sp. also had the highest concentrations of fructose (12.7 mg/g DM), sucrose (16.6 mg/g DM) and starch (934 mg/g DM). S. javanensis (357 mg/g MS), C. pulchra (343 mg/g MS), S. hirsutum (336 mg/g MS), Chlorococcum sp (307 mg/g MS), H. reticulata (306 mg/g MS) g MS), Kirchneriella sp. (304 mg/g MS) and C. vulgaris (303 mg/g MS) did not differ statistically from each other in terms of total soluble protein concentration. Chlorococcum sp., Chlorella vulgaris and Kirchneriella sp., can be considered for use in supplementing animal feed. The high starch content found in the studied species, especially in Scenedesmus sp., Chlorococcum sp. and S. hirsutum, also indicates the potential use of this biomass in the production of bioethanol. The increase in nitrogen and salinity positively affects the accumulation of proteins, while high light intensities favor the synthesis of carbohydrates and lipids. The environmental conditions used in cultivation affect the biochemical composition of cultivated microalgae and the morphological type of the species can influence the adopted metabolic response. The knowledge and manipulation of these parameters, associated with the morphological type of the cultivated microalgae, is an effective way to obtain biomass with greater added, nutritional and commercial value.