Partitioning taxonomic diversity of aquatic insect assemblages and functional feeding groups in neotropical savanna headwater streams.

Biological diversity can be divided into: alpha (α, local), beta (ß, difference in assemblage composition among locals), and gamma (γ, total diversity). We assessed the partitioning of taxonomic diversity of Ephemeroptera, Plecoptera and Trichoptera (EPT) and of functional feeding groups (FFG) in neotropical savanna (southeastern Brazilian cerrado) streams. To do so, we considered three diversity components: stream site (α), among stream sites (ß1), and among hydrologic units (ß2). We also evaluated the association of EPT genera composition with heterogeneity in land use, instream physical habitat structure, and instream water quality variables. The percentage of EPT taxonomic α diversity (20.7%) was smaller than the ß1 and ß2 diversity percentages (53.1% and 26.2%, respectively). The percentage of EPT FFG collector-gatherer α diversity (26.5%) was smaller than that of ß1 diversity (55.8%) and higher than the ß2 (17.7%) diversity. The collector-gatherer FFG was predominant and had the greatest ß diversity percentage among stream sites (ß1, 55.8%). Our findings support the need for implementing regional scale conservation strategies in the cerrado biome, which has been degraded by anthropogenic activities.

Quantificação de metabólitos secundários e avaliação da atividade antimicrobiana e antioxidante de algumas plantas selecionadas do Cerrado de Mato Grosso / Quantification of secondary metabolites and antimicrobial and antioxidant activities of some medicinal plants from the Cerrado of the Mato Grosso

RESUMO Extratos etanólicos de Luehea paniculata, Anadenanthera colubrina, Cariniana rubra, Hancornia speciosa, Qualea grandiflora, Kielmeyera coriaceae e Palicourea rigida, coletadas no Cerrado de Mato Grosso foram submetidos à análise fitoquímica preliminar para identificação das principais classes de metabolitos secundários e à quantificação do teor de compostos fenólicos totais, flavonoides e cumarinas. O estudo também descreve a atividade antimicrobiana, antioxidante e a toxicidade preliminar frente a larvas de Artemia salina. Os extratos de C. rubra e Q. grandiflora foram os mais ativos contra as cepas fúngicas de C. neoformans (CIM 3,91 µg/mL), C. krusei(CIM 15,63 µg/mL), C. parapsilosis (CIM 31,25 µg/mL) e C. albicans (CIM 62,5 µg/mL), ambos com os mesmos resultados para estes microrganismos. Em relação às cepas bacterianas a mais sensível foi S. aureus com CIM de 250 µg/mL para todos os extratos testados. Luhea paniculata e Q. grandiflora foram as espécies vegetais mais ativas contra E. coli (CIM 500 e 250 µg/mL, respectivamente) e E. faecalis (CIM 250 e 500 µg/mL, respectivamente). No teste do DPPH, merece destaque as espécies K. coriaceae (Ca) (IC50 = 0,72 ± 0,51 μg /mL), K. coriaceae (Fo) (IC50 = 1,34 ± 0,53 μg /mL), H. speciosa (Fo)(IC50 = 1,03 ± 0,52 μg /mL), Q. grandiflora (Fo) (IC50 = 1,31 ± 0,19 μg /mL) e P. rigida (Fo) (IC50 = 1,39 ± 0,53 μg /mL). Com exceção de L. paniculata(Fo), que apresentou IC50 de 14,40 ± 0,34 μg /mL e teor de flavonoides de 295,5 mg/g, todas as espécies que tiverem significativa atividade no teste do DPPH, também apresentaram teor de flavonoides semelhante ao padrão, ou seja, H. speciosa (Fo) (280,5 mg/g), Q. grandiflora(Fo) (260,5 mg/g), K. coriaceae (Ca) (250,5 mg/g), K. coriaceae (Fo) (235,5 mg/g). Quanto à determinação de fenóis totais e cumarinas os resultados foram inferiores quando comparados aos padrões.

ABSTRACT Ethanol extracts of Luehea paniculata, Anadenanthera colubrina, Cariniana rubra, Hancornia speciosa, Qualea grandiflora, Kielmeyera coriaceae and Palicourea rigida, collected in the Cerrado of Mato Grosso went through preliminary phytochemical analysis in order to identify major classes of secondary metabolites and also to quantify the total content of phenolics, flavonoids and coumarins. The study also describes the antimicrobial and antioxidant activity and the toxicity of the larva of Artemia salina. The C. rubra extracts and the Q. grandiflora were the most active against fungal strains of C. neoformans (MIC 3.91 µg/ml), C. krusei (MIC 15.63 µg/ml), C. parapsilosis(31.25 MIC µg/ml) and C. albicans (MIC 62.5 µg/ml), both with the same results for these organisms. Regarding the bacterial strains, the most sensitive one was the S. aureus with 250 µg/ml MIC for all the tested extracts. The Luhea paniculata and the Q. grandiflora were the most active against E. coli species (MIC 500 and 250 µg/ml, respectively) and E. faecalis (MIC 250 and 500 µg/ml, respectively). In the test of DPPH, K. coriaceae (Ca) (IC50 = 0.72 ± 0.51 µg/mL), K. coriaceae (Fo) (IC50 = 1.34 ± 0.53 µg/mL), H. speciosa (Fo) (IC50= 1.03 ± 0.52 µg/mL), Q. grandiflora (Fo) (IC50 = 1.31 ± 0.19 µg/ml) and P. rigida (Fo) (1.39 ± 0,53 µg/ml) stood out. With the exception of the L. paniculata (Fo), which showed an IC50 of 14.40 ± 0.34 µg/ml and a flavonoid content of 295.5 mg/g, all species that had significant activity in the DPPH test, also showed flavonoid content similar to the standard one, or H. speciosa (Fo) (280.5 mg/g) Q. grandiflora (Fo) (260.5 mg/g), K. coriaceae (Ca) (250.5 mg/g), K. coriaceae (Fo) (235.5 mg/g).

Development of a benthic multimetric index for biomonitoring of a neotropical watershed.

Biotic indices are important tools for evaluating water quality in Biomonitoring Programmes of river basins. The objective of this study was to develop a Benthic Multimetric Index (BMI) to evaluate the water quality in a neotropical catchment in southeastern Brazil. Thirty metrics were evaluated and six were selected to calculate the BMI: family richness, % Oligochaeta, % Chironomidae + Oligochaeta (% CHOL), % EPT (Ephemeroptera, Plecoptera and Trichoptera), % Collector-gatherers, and BMWP-CETEC biotic index. Sampling was carried in triplicate at 21 sampling sites (8 in the river channel and 13 in the tributaries) during 4 annual collecting trips from June 2004 to November 2007, making a total of 945 samples. Scores (5, 3 or 1) were attributed to each chosen metric and were added up to establish the water quality criteria (a score of 6-12 - poor; 13-18 - intermediate; 19-24 - good; and 25-30 - very good water quality). Our results indicated that 48% of the sampling sites analysed in the catchment basin presented very good water quality, 14% good quality, 19% regular, and 19% poor water quality. This methodology proved to be an efficient tool for evaluating water quality in the Biomonitoring Programme of the Velhas River basin, and that it may serve to evaluate water quality in other river basins in South America.

Malacological assessment and natural infestation of Biomphalaria straminea (Dunker, 1848) by Schistosoma mansoni (Sambon, 1907) And Chaetogaster limnaei (K. Von Baer, 1827) in an urban eutrophic watershed.

The objective of this study was to perform a malacological assessment at the Ibirité reservoir watershed in the metropolitan region of Belo Horizonte (Minas Gerais) and to evaluate the natural infestation rate of Biomphalaria straminea (Gastropoda: Planorbidae) by Schistosoma mansoni (Platyhelminthes: Trematoda) and Chaetogaster limnaei (Oligochaeta: Naididae). The samples were collected from July to August 2002. The B. straminea individuals collected were kept in the laboratory; the natural infestation rate by S. mansoni and C. limnaei was assessed weekly. The malacological assessment identified five mollusk species present in the Ibirité reservoir watershed: B. straminea, Physa marmorata, Lymnea sp., Melanoides tuberculatus, and Pomacea austrum. Laboratory observations showed that the B. straminea individuals were infected by C. limnaei rather than S. mansoni. Although there was no infection of B. straminea by S. mansoni, presence of B. straminea in itself merits close attention due to possible risk of human schistosomiasis by the local population.

Malacological assessment and natural infestation of Biomphalaria straminea (Dunker, 1848) by Schistosoma mansoni (Sambon, 1907) and Chaetogaster limnaei (K. von Baer, 1827) in an urban eutrophic watershed

O objetivo deste estudo foi realizar um levantamento malacológico na bacia do reservatório de Ibirité, na região metropolitana de Belo Horizonte (Minas Gerais), e avaliar a taxa de infestação natural de Biomphalaria straminea (Gastropoda: Planorbidae)por Schistosoma mansoni (Platyhelminthes: Trematoda) e Chaetogaster limnaei (Oligochaeta: Naididae). As amostragens foram realizadas de julho a agosto de 2002. Os espécimes de B. straminea coletados foram levados para o laboratório e as avaliações da taxa de infestação foram realizadas semanalmente. O levantamento malacológico identificou cinco espécies de moluscos presentes na bacia do reservatório: B. straminea, Physa marmorata, Lymnea sp., Melanoides tuberculatus e Pomacea austrum. As observações em laboratório mostraram que os espécimes de B. straminea estavam infectados somente por C. limnaei. Apesar de não ter sido encontrado S. mansoni, a presença desse planorbídeo deve ser vista com atenção, em decorrência da possibilidade de infecção com esquistossomose humana para a população local.