Efeito do extrato aquoso de folhas de guanandi (Calophyllum brasiliense Cambess) no controle do crescimento de Microcystis aeruginosa

Abstract

A água corresponde ao recurso da maior importância para a sobrevivência de toda a vida do planeta. O aumento das atividades agrícolas, urbanas e industriais, acarretam o acúmulo de efluentes ricos em fósforo e nitrogênio nos corpos d’água, causando a eutrofização. Em termos de qualidade de água, a eutrofização pode causar alteração na disponibilidade de oxigênio dissolvido, morte extensiva de peixes e aumento da incidência de florações de cianobactérias. A principal preocupação com as cianobactérias é a capacidade produzirem e liberarem as microcistinas, um grupo de hepatotoxinas, que é muito associada a incidentes de intoxicação em todo o mundo. O Guanandi (Calophyllum brasiliense Cambess) é uma árvore de grande porte, que cresce em regiões de floresta da Mata atlântica, amazônica e em determinados locais do cerrado, desde a América Central até litoral norte de Santa Catarina, apresenta em extratos brutos de diferentes partes da planta (raízes, caules e folhas) atividade antibacteriana contra bactérias Gram-positivas e sobre algumas cepas Gram-negativas. O objetivo deste trabalho, foi avaliar o efeito de extratos ...

The expansion of the agricultural, urban and industrial activities leads to the accumulation of effluents like phosphorus and nitrogen in water bodies, causing eutrophication. In terms of water quality, eutrophication, can affect the oxygen dissolved availability, fish mortality and increased incidence of cyanobacteria blooms. The main concern with cyanobacterias is its ability to produce and release microcystins, a group of hepatotoxins, which is closely associated with poisoning incidents worldwide. Guanandi (Calophyllum brasiliense Cambess) is a tree that grows in areas of Atlantic Forest, Amazon and certain sites of Cerrado, from Central America until the northern coast of Santa Catarina. Crude extracts from different parts of the tree (roots, stems and leaves) has demonstrated 4 antibacterial activity against Gram-positive bacteria and some of gram-negative strains. The objective of this work was to use an extract made with leaves of fifteen Guanandi plants (Calophyllum brasiliense Cambess) to control the growth of a strain of Microcystis aeruginosa, that can produces microcystin. The preparation of the extracts, was performed with the decomposition of leaves, in water from the reservatory of Barra Bonita, Brazil. The experiments were conducted in BG 11 culture medium, where 10% of the volume of the medium was supplemented with the extracts from the leaves, with different periods of decomposition (7, 15, 30 and 60 days), inoculated with approximately 109 cells of Microcystis aeruginosa and incubated in a climatic chamber under controlled conditions (30 ° C and 12 hour photoperiod), after 10 days analyzes were performed for: chlorophyll content to determine the growth and the content of microcystin produced and released in the supernatant. The results showed that the extracts can reach 90% of cyanobacteria growth inhibition in culture medium, with growth inhibition also reduces the amount ...