Decolorization of different textile dyes by Penicillium simplicissimum and toxicity evaluation after fungal treatment

The objective of this study was to investigate the capacity of decolorization and detoxification of the textile dyes Reactive Red 198 (RR198), Reactive Blue 214 (RB214), Reactive Blue 21 (RB21) and the mixture of the three dyes (MXD) by Penicillium simplicissimum INCQS 40211. The dye RB21, a phthalocyanine, was totally decolorized in 2 days, and the others, the monoazo RR198, the diazo RB214 and MXD were decolorized after 7 days by P. simplicissimum. Initially the dye decolorization involved dye adsorption by the biomass followed by degradation. The acute toxicity after fungal treatment was monitored with the microcrustacean Daphnia pulex and measured through Effective Concentration 50 percent (EC50). P. simplicissimum reduced efficiently the toxicity of RB21 from moderately acutely toxic to minor acutely toxic and it also reduced the toxicity of RB214 and MXD, which remained minor acutely toxic. Nevertheless, the fungus increased the toxicity of RR198 despite of the reduction of MXD toxicity, which included this dye. Thus, P. simplicissimum INCQS 40211 was efficient to decolorize different textile dyes and the mixture of them with a significant reduction of their toxicity. In addition this investigation also demonstrated the need of toxicological assays associated to decolorization experiments.

Sewage input effects on the macroinvertebrate community associated to Typha domingensis Pers in a coastal lagoon in southeastern Brazil

This study was carried out at Imboassica Lagoon, located in an urban zone in the municipality of Macaé, Rio de Janeiro state, Brazil. This lagoon has been subject to anthropogenic impacts due to the increasing city population, such as the input of sewage. Areas of variable degree of anthropogenic influence in the lagoon were compared regarding the structure of the macroinvertebrate community associated to Typha domingensis leaves. For sampling, we used 35 x 20 cm net plastic bags, with 6.8 mm mesh containing T. domingensis leaves for colonization. Two different sampling stations were selected: station A, under direct input of sewage; and station B with lesser sewage influence. The bags were removed after 20, 40 and 75 days of colonization. For each sample the Shannon-Wiever Diversity, Pielou Evenness, Jaccard Similarity Indices, Correspondence Analysis and taxonomic richness were calculated. A total of 31,874 individuals were sampled, belonging to 34 taxa. The main taxonomical groups were: Oligochaeta (41 percent), Chironomidae (40 percent), Ancylidae (4.6 percent), Polymitarcyidae (4 percent) and Thiaridae (3 percent). At station A, the taxonomic richness, the Evenness and Diversity values were lower than in station B. On the other hand, the total density was three times higher in station A than in B. It was already possible to discriminate the community structure of each sampling station in the first sampling. Trichoptera and Ephemeroptera were the main exclusive groups of station B and are considered good water quality indicators due to their high sensibility to contamination. The major contribution to discriminate between the macroinvertebrate communities of the two sample stations came from Chironomidae, Oligochaeta and Ephemeroptera.

O presente estudo foi realizado na Lagoa Imboassica, localizada no perímetro urbano da cidade de Macaé, RJ, Brasil. Esta lagoa vem sofrendo impactos antrópicos com o aumento da cidade, como o aporte de esgotos sem tratamento. Areas com diferentes graus de influência antrópica na lagoa foram comparadas quanto à estrutura da fauna de macroinvertebrados associada a folhas de Typha domingensis. A amostragem da fauna foi realizada por meio de cestos de tela plástica de 35 x 20 cm e malha de 6,8 mm, com folhas de T. domingensis para colonização. Dois pontos amostrais foram selecionados: ponto A, sujeito a aporte direto de esgotos; e ponto B, sob menor influência de esgotos. Os cestos foram retirados após 20, 40 e 75 dias de colonização. Foram aplicados em cada amostra os índices de diversidade de Shannon-Wiever, equitabilidade de Pielou e similaridade de Jaccard, riqueza taxonômica e Análise de Correspondência. Foram encontrados 31.874 indivíduos, distribuídos em 34 táxons. Os principais grupos foram: Oligochaeta (41 por cento); Chironomidae (40 por cento); Ancylidae (4,6 por cento); Polimitarcyidae (4 por cento); e Thyaridae (3 por cento). No ponto A, os valores de riqueza taxonômica, equitabilidade e diversidade foram inferiores aos do ponto B. Por outro lado, a densidade total foi três vezes maior no ponto A. A estrutura da comunidade foi diferente nos dois pontos amostrais para todos os testes utilizados, desde a primeira retirada. Trichoptera e Ephemeroptera foram os principais grupos exclusivos do ponto B, sendo considerados indicadores da qualidade da água devido à sua sensibilidade. Chironomidae, Oligochaeta e Ephemeroptera foram os principais grupos a contribuir com as diferenças nas comunidades de macroinvertebrados entre os pontos amostrais.

Spatial and temporal distribution of benthic macroinvertebrates in a Southeastern Brazilian river

A fauna de macroinvertebrados bentônicos é estruturada por fatores físicos e químicos que determinam os microhábitats, incluindo a disponibilidade de alimento, a existência de refúgios contra predadores e tempestades, o sucesso reprodutivo e outros parâmetros biológicos. O objetivo deste estudo foi investigar a distribuição espaço-temporal da comunidade de macroinvertebrados bentônicos na bacia do rio Macaé, Estado do Rio de Janeiro, Brasil. De acordo com o Habitat Assessment Field Data Sheet – High Gradient Streams (Barbour et al., 1999), os cinco locais coletados são considerados como referência para propósito de biomonitoramento. Apesar das diferenças em parâmetros hidrográficos (largura, profundidade e vazão médias), os parâmetros físico-químicos e a composição dos grupos de alimentação funcional foram similares entre os locais, com exceção da área mais preservada, onde a porcentagem de organismos cortadores foi maior. De acordo com a Análise de Correspondência, há uma clara distinção entre áreas de remanso e de correnteza. De fato, o substrato folhiço de correnteza apresentou a fauna mais rica e abundante, enquanto o substrato folhiço de fundo apresentou o maior número de táxons exclusivos. A Análise de Agrupamento considerando os dados dos locais de coleta indicou que a variação temporal foi o fator mais importante na estruturação das comunidades nos hábitats estudados.

Diversity and habitat preference of aquatic insects along the longitudinal gradient of the Macaé River basin, Rio de Janeiro, Brazil

Diversity and habitat preference of macroinvertebrates were studied in MacaÚ River basin, Rio de Janeiro State, Brazil, along its longitudinal gradient. We selected stream reaches corresponding to 1st, 2nd, 4th, 5th and 6th orders. A Surber sampler was used to collect four macroinvertebrates samples of each substrate (sand, litter in pool areas, stones, and litter in riffle areas) during the three sampling periods, defined based on the rain regime: April (end of the rainy season), July (dry season), and October (beginning of the rainy season). We identified 46,431 specimens corresponding to 117 taxa. Analysis of diversity numbers (both for family or genus level) indicated that all insect taxonomic orders had higher numbers on 2nd order stream reach, except for Ephemeroptera, on 4th order. However when considering morph-species taxonomic level, the higher diversity number occurred on 4th order stream. The highest richness and diversity numbers were found at the dry season. Considering habitat preference, both litter in pool areas and litter in riffle areas had the highest faunal richness

Spatial and temporal organization of aquatic insects assemblages in the longitudinal gradient of a tropical river

The distribution and abundance of aquatic insects were studied in the longitudinal gradient of the watershed of MacaÚ River, a coastal Atlantic Forest river in South-eastern Brazil. Sampling stations were selected in the first, second, fourth, fifth, and sixth orders and sampled in April, July, and October 1995. This represented the end of the rainy season, the dry season, and the beginning of another rainy season, respectively. In each month four samples were collected using a Surber sampler from each of the following substrates: sand, litter deposited in pool areas, litter in riffle areas, and stones. A total of 46,431 specimens of aquatic insects belonging to ten orders were obtained. The data were analyzed by the multivariate methodologies of Correspondence Analysis (CA) and Cluster Analysis (UPGMA) using the similarity index of Morisita, for all three months. Both showed a significant faunal disrupture in the river, which can be divided in two sections: the upper one, from first to fourth orders, and the lower section, including fifth and sixth orders. The same results were obtained with presence-absence matrices, using Jaccard similarity index, showing that the changes are not only due to quantitative differences. A Mantel test was used to compare the assemblage composition temporally and no difference was detected between the three months. Moreover, a Canonical Correspondence Analysis (CCA) was applied to the data to check which of the 14 physical and chemical variables significantly explained macroinvertebrate community variation. The most significant variables were conductivity, CPOM, and pH for the upper stations (1st, 2nd and 4th orders), and alkalinity, FPOM, and HCO3 for the lower stations (5th and 6th orders)

Perspectives of using Euphorbia splendens as a molluscicide in schistosomiasis control programs.

A total of 1,426 species of plants had been tested in order to find out a vegetal-derived molluscicide against the vectors of Schistosoma mansoni. Euphorbia splendens is one of the most promising molluscicides. In this article we briefly present the main aspects that have to be considered to use this plant as a molluscicide, which include some agricultural aspects and operational methods for application. This can be done by the extraction of the active principles (millaminas) present in the latex or in the raw juice obtained through total maceration of plants. The culture of E. splendens, which spreads out by vegetative sprouts, showed an annual average growth of 30 cm. After 1.5 years the average productivity of crude latex with a DL90 of 12 ppm concentration, was 1 liter by 8m2 by cultivated area. This amount is enough to treat a volume of water of 97,200 liters. A comparative analysis between the cost of snail control through synthetic molluscicides was carried out based upon the data presented by Jobim (1979) for six controlling methods in several countries, and some cost aspects for E. splendens. This analysis was done considering a geographic parameter expressed by the index cubic meters of treated habitat per square kilometer, from which we can obtain an estimate dimension of the geographic area to be cultivated with E. splendens necessary to treat the same volume of water treated by synthetic molluscicides.

Evaluation of the molluscicidal property of Euphorbia splendens var. Hispolii (N.E.B.) (Euphorbiaceae): 2. Investigation in lotic habitat

The latex of Euphorbia splendens var. hispolii in 12 ppm concentration (12 mg/l) caused 100% mortality for a Biomphalaria tenagophila population in a lotic habitat after 9 hr of dripfeed application. For sentinel snails, in cages placed at the water surface and buried under 0.10 m, the mortality rates varied with the distance from the application point and were: 100% (0 m); 92.6% (50 m) and 94.7% (100). No lethal effects were observed for the other living species in this habitat (Pomacea haustrum and Poecilia reticulata)

Study of a population of Biomphalaria tenagophila (Orbigny, 1835) and of schistosomiasis transmission in "Alto da Boa Vista", Rio de Janeiro

O presente trabalho foi realizado com dados obtidos de uma populaçäo de Biomphalaria tenagophila em uma horta de agriäo na regiäo do Alto da Boa Vista, foco isolado de esquistossomose na cidade do Rio de Janeiro. Foram feitas observaçöes sobre mudanças sazonais na densidade e estrutura etária da populaçäo de B. tenagophila e taxas de infecçäo desses caramujos pelo Schistosoma mansoni durante um periodo de 15 meses. A populaçäo de caramujo mostrou variaçäo sazonal com diminuiçäo do número de animais no ínicio da estaçäo chuvosa, sendo constituída no final desta estaçäo principalmente de adultos (92,8% maio 85 - 82,9% abril 86). A populaçäo apresentou uma curva de crescimento logística de configuraçäo sigmoide. A liberaçäo de cercárias de S. mansoni e de ave parece depender da temperatura ambiental que chegou a uma amplitude diária de até 13-C

Structural and function analysis of the eye of Biompharia glabrata (Mollusca, Gastropoda, Basommatophora)

The eye of the snail Biomphalaria glabrata was studied at the light microscope level. The eye is a spherical lens bathed in humor (vitreous body) ans surrounded by the corneal and retinal cell layers. 2. The retina is composed of four layers: the inner photoreceptor layer close to the ocellar cavity, a pigmented layer, a nuclear, and the fibrous layer. The nuclear layer contains the nuclei of the supporting cells and of two types of sensory cells that are similar to those described for other gastropod molluscs. 3. Calculations of optical properties showed that eye of B. glabrata is slightly hypermetropic and has limited resolving power. 4. The results are discussed in terms of the importance of visual information for the behavior of this animal