ABSTRACT This research aimed to produce activated carbon (AC) from the seed of açaí of the native species Euterpe precatoria, as well as to perform physical analysis of the AC and verify its filtering capacity. For this, three different types of AC were carried out, two of which were carried out in the laboratory with the variation of temperature and exposure time and another type of AC carried out in the field (rural area). The AC produced, both in the laboratory and in the field, had a significant reduction in apparent mass and electron microscopy proved to be of good quality. The filter with açaí stone charcoal proved to be effective in partially removing coliforms and with a significant increase in pH, it raised alkalinity and conductivity levels, reduced hardness and improved turbidity, and proved to be a great tool that, added to the chlorination process, it can take treated water to isolated communities that do not have access to treated water, having characteristics of low cost and reuse of waste.

RESUMO Esta pesquisa teve como objetivo produzir carvão ativado (CA) a partir do caroço do açaí da espécie nativa Euterpe precatoria, bem como realizar análises físicas do CA e verificar a sua capacidade de filtragem. Para isso, foram realizados três diferentes tipos de CA, sendo dois feitos em laboratório com a variação de temperatura e tempo de exposição e outro tipo de CA realizado em campo (área rural). O CA produzido, tanto em laboratório, como em campo, teve significativa redução de massa aparente e a microscopia eletrônica comprovou ser de boa qualidade. O filtro com o carvão de caroço de açaí mostrou-se eficaz na remoção parcial de coliformes e com um aumento significativo do pH, elevou os níveis de alcalinidade e condutividade, reduziu a dureza e melhorou a turbidez, e provou ser uma ótima ferramenta que, somada com o processo de cloração, pode levar água tratada a comunidades isoladas que não tem acesso a água tratada, tendo características de baixo custo e reaproveitamento de resíduos.

RESUMEN Las termitas del género Nasutitermes son consideradas una de las principales plagas urbanas y agroforestales de Brasil, donde el principal método de control es la aplicación de pesticidas. Los hongos entomopatógenos pueden ser usados como alternativa para reducir la población de esta plaga en el medio ambiente. Por tanto, el objetivo de este estudio fue evaluar la virulencia de aislados de hongos nativos de suelo amazónico pertenecientes a las especies Tolypocladium endophyticum, Metarhizium anisopliae y Metarhizium marquandii para el control de Nasutitermes sp. Las cepas de T. endophyticum (4,439), M. anisopliae (4,443) y M. marquandii (4,472) con sus respectivos códigos de aislamiento, fueron evaluadas utilizando suspensiones a concentraciones de 105, 106, 107 y 108 conidios/mL contra las termitas. Los hongos se caracterizaron mediante análisis moleculares para confirmar la especie. La mayor virulencia se registró con el hongo T. endophyticum (4,439), con una mortalidad del 100 % al cuarto día de tratamiento para todas las concentraciones analizadas. La cepa M. anisopliae (4,443) demostró ser eficiente, causando una mortalidad del 100 % al sexto y septimo días a las diluciones de 107 y 108 conidios / mL, respectivamente. Se registraron tasas inferiores al 100 % con M. marquandii (4,472). Por tanto, las tres cepas de hongos mostraron virulencia contra las termitas Nasutitermes sp. En este estudio, los hongos Tolypocladium endophyticum y Metarhizium marquandii son reportados por primera vez para el control biológico de plagas, indicando el potencial de hongos nativos de suelo amazónico para el control biológico de termitas Nasutitermes sp.

ABSTRACT Termites of the Nasutitermes genus are considered one of the main urban and agroforestry pests in Brazil, where the main method of control is the application of pesticides. The uso of entomopathogenic fungi to reduce the population of this plague in the environment could be use as an alternative. The goal of this study was to evaluate the virulence of isolates native Amazonian fungi belonging to the Tolypocladium endophyticum, Metarhizium anisopliae and Metarhizium marquandii species for the control of Nasutitermes sp. The strains of T. endophyticum (4.439), M. anisopliae (4.443) and M. marquandii (4.472) with their respective isolation codes, were evaluated using suspensions at concentrations of 105, 106, 107 and 108 conidia/mL against the termites. The fungi were characterized to species level by molecular analysis. The greatest virulence was registered with T. endophyticum (4.439), with a mortality of 100 % on the 4th day of treatment for all analyzed concentrations. The M. anisopliae strain (4.443) proved to be efficient, causing a mortality of 100 % on the 7th and 6th days at dilutions of 107 and 108 conidia/mL, respectively. Rates lower than 100 % were registered with M. marquandii (4.472). Therefore, the three fungal strains showed virulence against the termites Nasutitermes sp. In this study, the fungi Tolypocladium endophyticum and Metarhizium marquandii are reported for the first time for the biological control of pests, indicating the potential of native Amazonian fungi for the biological control of thermites Nasutitermes sp.

Seed priming with hormones has been an efficient method for increasing seed vigor as well as seedling growth under stressful conditions. These responses have in the past been attributed to the activation of antioxidant systems in a range of crops. The results described in this work show that hormonal priming with methyl jasmonate, salicylic acid or CEPA (chloroethylphosphonic acid), an ethylene (ET) releaser, does not induce the antioxidant activity of superoxide dismutase, catalase, ascorbate peroxidase or glutathione reductase in maize seedlings subjected to salt stress. The enhanced biomass of maize seedlings under salt stress that was observed only from ET priming indicates that the stress tolerance in maize from ethylene priming is a fundamental process for stress tolerance acquisition, which is explained, however, by other biochemical mechanisms but not by changes in the antioxidant system.