Capacidade de Eichhornia azurea (Swartz) Kunth de depurar água contaminada por coliformes termotolerantes

A fim de colaborar com o desenvolvimento sustentável, dentro da proposta de utilizar sistemas biológicos para tratamentos hídricos de baixo custo, propondo uma alternativa natural e limpa, a biorremediação, em especial a técnica de fitorremediação com macrófitas aquáticas, é uma estratégia que vem se destacando. O objetivo deste trabalho foi verificar a capacidade do aguapé Eichhornia azurea (Swartz) Kunth de depurar água contaminada por coliformes termotolerantes. O trabalho de pesquisa foi desenvolvido no Laboratório de Microbiologia da Universidade do Estado da Bahia (UNEB), Campus X, Teixeira de Freitas-BA. Inicialmente, foi realizada uma coleta da espécie no rio Itanhém. Após o período adaptativo, espécimes da planta foram distribuídos em quatro diferentes tanques, cada um contendo características distintas de nível de contaminação por coliformes. Foram realizadas coletas da água de cada tanque para análise microbiológica, semanalmente. Os dados obtidos foram estruturados em tabelas e gráficos. O método utilizado para testar a hipótese de diferença considerável entre os tanques de tratamento e o tempo de perda de contaminação da água foi Análise de Variância utilizando o teste t de Student. Foi possível constatar a redução das populações de coliformes presentes nos tanques experimentais, onde o decaimento médio de coliformes foi de 3,34895 log NMP/100 mL. Além disso, foi realizada a análise do ganho de peso dos espécimes da planta, que chegaram a um ganho de até 64% do peso inicial. A espécie analisada apresentou potencial para uso em técnicas de fitorremediação.

Aerial Biomass and Nitrogen Estimation of Emerged and Floating Macrophytes using Optical Remote Sensing: A Non-Destructive Method

Freshwater resources faces threats with aquatic plants invasion, considered biological pollution with deep effects on water quality and nutrients cycling due to their rapid growth. Orbital remote sensing has been an effective instrument of monitoring large water bodies. Thus, the aim of this study was to analyze the relation between reflectance and field measurements (biomass and nitrogen concentration) of aquatic plants to develop estimation equations and to test vegetation indices to use in orbital remote sensing. The most common tropical infesting species (Salvinia auriculata, Pistia stratiotes, Eichhornia crassipes and Eichhornia azurea) were collected during a year, measured their spectral response to simulate satellite bands, and the biomass and nitrogen concentration measurements. The bands intervals of Sentinel-2 satellite were choosing to the simulation due to their narrow bands and the RedEdge new band. The obtained field data were correlated with the reflectance obtained from spectroradiometry of each species and the equations showed R² = 0.64 to estimate biomass and R² = 0.60 to estimate nitrogen using the entire spectrum. Several indices described in the literature were tested with different Sentinel-2 bands but with no significant results. The NDVI index showed a separation among species using RedEdge band and can be used to identify the species, but not to estimate their biomass.

Staurosirella paranaensis sp. nov., a new epiphytic freshwater diatom (Bacillariophyceae) from the Paraná River floodplain, Brazil, South America

A new diatom species, Staurosirella paranaensis, is described only from epiphytic samples on the macrophyte Eichhornia azurea in a lake from the Upper Paraná River Floodplain in Brazil. Description of the new taxon is based on morphological characteristics observed using light and scanning electron microscopy. The new species is characterized by short elliptic valves with an axial area narrowly lanceolate, sometimes giving the impression of having a zig-zag form due the alternating nature of the striae. The lineolate striae, running uninterrupted from valve face to mantle. Spines are solid, thin, spatulate with two prominences at the top, located at the costae. Apical pore fields are inconspicuous, located at both apices and equally developed on both valves. Girdle elements variable in number, open, lacking pores, ligulated, and with valvocopula being much larger. The species previously identified in the region as the “catch-all” taxon “Staurosirella (Staurosira) pinnata” is placed in the genus Staurosirella based on the striae bearing well-developed internal vimines delimiting typically long areolae. Comparisons with similar species ascribed to the genus Staurosirella are provided to highlight the peculiar characteristics of S. paranaensis.

Sewage and natural water treatment with higher plants

The application of Eichhornia azurea and Eichornia crassipe for the treatment of organomineral wastewater of small production facilities in model experiments and the waters of surface water bodies saturated with nutrients was studied.

Evaluación de diferentes sustratos enriquecidos con microorganismos para la producción de compost en áreas naturales

La práctica de elaboración y aplicación del compost se acepta ampliamente como sostenible en la producción de cultivos. La investigación se realizó en la Unidad Científico Técnica Base “UCTB Suelos Cienfuegos”, Cuba con el objeto de evaluar el proceso de compostaje a partir de diferentes combinaciones de residuos de plantas (Sacharum officinarum, Pennisetum purpureum, Leucaena leucocephala, Eichhornia azurea y Oryza sativa) y la adición de un inoculante microbiano. Se condujeron cinco tratamientos con tres repeticiones en un diseño de Bloques al azar. Se midió la temperatura durante todo el proceso, la descomposición y se determinó la composición química del compost obtenido. El comportamiento de la temperatura mantuvo indistintamente en todos los tratamientos la secuencia de fases: Mesófila, Termófila y Mesófila II, con una duración del proceso de compostaje en los tratamientos que contenían S. officinarum y P. purpurea entre 105-110 días y un porcentaje de descomposición de 78,2%, 84,6% y 88,6% respectivamente; mientras que, en los tratamientos que contenían E. azurea y O. sativa la duración estuvo entre 135-140 días, con una descomposición de 68% y 69,4% respectivamente, sin que dicha extensión influyera en la descomposición alcanzada. Al evaluar los resultados se concluye que todos los tipos de compost obtenidos son viables para su uso, teniendo en cuenta sus propiedades, con destaque para el tratamiento con S. officinarum 3, que tuvo los mayores valores de nitrógeno 1,55%, potasio 1,87%, materia orgánica 62,8%, fósforo de 0,53%, relación carbono nitrógeno 23,29 y el mayor porcentaje de descomposición.

Fitoperifíton asociado con macrófitas en una ciénaga tropical de la cuenca del río Atrato, Quibdó (Chocó), Colombia

El fitoperifíton es una de las comunidades más importantes en las ciénagas o lagos de planos inundables por el papel que desempeña en el flujo de la energía, el ciclo de nutrientes y la productividad primaria de estos importantes ecosistemas. En este estudio se analizó la comunidad fitoperifítica asociada con tres especies de macrófitas (Ludwigia sedoides Humb. and Bonpl. Hara 1953, Nymphoides indica L. Kuntze, 1891 y Eichhornia azurea Swartz. Kunth, 1843) en una ciénaga tropical de la cuenca del río Atrato, Chocó, Colombia. Los muestreos se realizaron entre mayo y agosto del 2014 mediante la recolección de muestras de fitoperifíton de raíces de tres ejemplares de cada especie estudiada. Simultáneamente se midieron algunas variables físicas y químicas del agua circundante. Se registró una densidad de 1.160,63 ind.cm-2, distribuida en 82 morfoespecies, 26 familias, 16 órdenes y ocho clases, siendo la clase Bacillariophyceae la más abundante en las tres especies estudiadas. L. sedoides presentó la mayor densidad y riqueza fitoperifítica asociada. Se registraron diferencias en los valores de densidad, riqueza, diversidad y dominancia del fitoperifíton de las macrófitas estudiadas (p<0,05). El análisis de agrupamiento basado en el índice de Jaccard indicó poca similitud en la composición de la comunidad perifítica entre las especies de macrófitas, así como un marcado efecto del periodo hidrológico. En el estudio se establece la línea de base para el conocimiento de las comunidades fitoperifíticas asociadas con macrófitas en las ciénagas de zonas bajas tropicales como las del río Atrato.

Notes on the genus Euastrum (Desmidiaceae) in Brazil, with description of a new species

We report here seven interesting taxa of Euastrum from the periphytic material of three macrophyte species (Cabomba haynesii, Eichhornia azurea, and Utricularia foliosa) occurring in the Chapada Diamantina, Bahia State, Brazil. Of those Euastrum taxa, E. westenii is new to science; E. bidentatum var. scottii, E. elegans var. prescottii, and E. informe var. oculatum were raised to the varietal level; E. ansatum var. concavum, E. ciastonii, and E. sibiricum had their geographic distributions enlarged to northeastern Brazil. Taxonomic notes and ecological information are provided for all taxa.

Taxonomy of common taxa of Chlorophyceae (Chlorophyta) and Zygnematophyceae (Streptophyta) from periphyton of a Neotropical floodplain

Some orders of algal groups such as Chlorophyceae and Zygnematophyceae have been reported as frequent taxa in periphytic communities of wetlands. The present study aimed at submitting these algal members which occurred in high abundance and frequency in the periphyton of 30 environments of the Upper Paraná River floodplain to a taxonomic survey and to present some ecological data concerning their richness. Periphyton were collected from petioles by scraping of Eichhornia azurea (Sw.) Kunth and preserved with Lugol acetic solution in the Upper Paraná River, Brazil, during high water period in March 2010. Taxa were counted in inverted microscope and those higher than 2,500 individuals in density with frequency of occurrence less than 50% simultaneously in the 30 environments sampled were subjected to a detailed taxonomical treatment under optical microscope coupled to a light camera and ocular micrometer under 1000x. Identifications and descriptions were made according to the algal literature. Some abiotic data were shown. Fifteen taxa belonging to the classes Chlorophyceae and Zygnematophyceae were abundant representing 64.6% of the total density. A Procruste analysis within a Detrended Correspondence Analysis showed that distribution pattern of richness of clorophyceans and zygnematophyceans was represented by common species of these communities, highlighting the importance of knowing about these algae taxonomy