Luiz Fernando Romanholo Ferreira

Evaluation of sugar-cane vinasse treated with Pleurotus sajor-caju utilizing aquatic organisms as toxicological indicators

Toxicity tests with aquatic organisms constitute an effective tool in the evaluation, prediction and detection of the potential effect of pollutants from environmental samples in living organisms. Vinasse, a highly colored effluent, is a sub-product rich in nutrients, mainly organic matter, with high pollutant potential when disposed in the environment. Assays for vinasse decolorization were performed using the fungus Pleurotus sajor-caju CCB020 in vinasse biodegradation study, were occurred reductions of 82.8% in COD, 75.3% in BOD, 99.2% in the coloration and 99.7% in turbidity. The vinasse toxicity reduction was determined by the exposition to the following organisms: Pseudokirchneriella subcapitata, Daphnia magna, Daphnia similis and Hydra attenuata. This work concluded that the systematic combination of P. sajor-caju and vinasse can be applied in the bioprocess of color reduction and degradation of complex vinasse compounds, with reduction in the toxicity and improving its physical-chemical properties.

Use of vinasse and sugarcane bagasse for the production of enzymes by lignocellulolytic fungi

In this present work, three strains of Pleurotus an d Trichoderma reesei were cultivated in media with pre-treated bagasse and vinasse. Cellulolytic and lignolytic ac tivities and biomass production were analyzed. The treatment of the bagasse with 2% H 2O2 + 1.5% NaOH + autoclave resulted in a greater fibe r breakage increasing the cellulose level up to 1.2 times and decreasing 8.5 times the hemicellulose content. This treatment also resulted in a high lignolytic activity for all cultures utilized. T. reesei produced laccase, peroxidase and manganese-pe roxidase in all the treatments, having its manganese-peroxidase act ivity raging from 1.9 to 4.8 times higher than the basidiomycetes.

Antimicrobial volatile organic compounds affect morphogenesis-related enzymes in Guignardia citricarpa, causal agent of citrus black spot.

Although non-volatile substances toxic to plant pathogenic microorganisms have been extensively studied over the years, few studies have focused on microbial volatile organic compounds (VOCs). The VOCs produced by the yeast Saccharomyces cerevisiae strain CR-1, used in fermentative processes for fuel ethanol production, are able to inhibit the vegetative development of the fungus Guignardia citricarpa, causal agent of the disease citrus black spot. How microbial VOCs affect the development of fungi is not known. Thus, the objective of the present work was to study the effect of the artificial mixture of VOCs identified from S. cerevisiae on intracellular enzymes involved in the mycelial morphogenesis in G. citricarpa. The phytopathogenic fungus was exposed to artificial mixture of VOCs constituted by alcohols (ethanol, 3-methyl-1-butanol, 2-methyl-1-butanol and phenylethyl alcohol) and esters (ethyl acetate and ethyl octanoate) in the proportions naturally found in the atmosphere produced by the yeast. The VOCs inhibited considerably the mycelial development and interfered negatively with the production of the morphogenesis-related enzymes. After 72 h of exposure to the VOCs the laccase and tyrosinase activities decreased 46 and 32%, respectively, however, the effect on the chitinase and β-1,3-glucanase activities was lower, 17 and 13% of inhibition, respectively. Therefore, the exposure of the fungus to the antimicrobial volatiles can influence both fungal mycelial growth rate and activity of enzymes implicated in morphogenesis. This knowledge is important to understand the microbial interactions mediated by VOCs in nature and to develop new strategies to control plant pathogens as G. citricarpa in postharvest.

Protistas ciliados e seu potencial uso como bioindicadores de qualidade de água

RESUMO: A contaminacao dos ecossistemas aquaticos por substâncias quimicas provenientes de atividades agricolas inadequadas e do despejo irregular de efluentes tem se intensificado. Assim, e indispensavel o uso de organismos que possam indicar a presenca desses contaminantes ou a qualidade dos corpos hidricos. O objetivo do presente trabalho foi realizar uma revisao de bibliografica sobre os aspectos gerais dos protistas ciliados ressaltando a importância da utilizacao desses organismos como bioindicadores em estudos de monitoramento de qualidade de agua e em ensaios de ecotoxicidade com contaminantes aquaticos. De acordo com essa pesquisa, os protistas ciliados sao excelentes organismos para serem utilizados como bioindicadores de qualidade de agua em programas de monitoramento devido a sua abundância, ciclo de vida curto, sensibilidade as alteracoes fisicas, quimicas e biologicas no ambiente aquatico, facilidade de manutencao em laboratorio e prevalencia em corpos hidricos. Os estudos com esses ciliados podem ser focados tanto em analises da diversidade, riqueza e abundância de especies em ecossistemas aquaticos como em avaliacoes da ecotoxicidade de contaminantes que podem atingir corpos d´agua. Nos estudos de monitoramento da qualidade de agua que incluem determinacao da riqueza, abundância e diversidade em ambientes impactos as especies identificadas podem variar de uma regiao para outra, enquanto que em ensaios laboratoriais de toxicidade as especies dos generos Tetrahymena e Paramecium sao internacionalmente as mais utilizadas. PALAVRAS-CHAVE: Protozoarios. Ecotoxicidade. Paramecium . Contaminantes. Ciliated protists and its potencial use as bioindicators of water quality ABSTRACT: Contamination of aquatic ecosystems by chemicals from inadequate agricultural activities and irregular effluent disposal has intensified. Thus, the use of organisms that may indicate the presence of these contaminants or the quality of the water bodies is indispensable. The objective of the present paper was to perform a literature review on the general aspects of ciliate protists emphasizing the importance of using these organisms as bioindicators in water quality monitoring studies and in aquatic contaminant ecotoxicity tests. According to this research, ciliary protists are excellent organisms to be used as bioindicators of water quality in monitoring programs due to their abundance, short life cycle, sensitivity to physical, chemical and biological changes in the aquatic environment, ease of maintenance In laboratory and prevalence in water bodies. Studies with these ciliates can be focused on analyzes of the diversity, richness and abundance of species in aquatic ecosystems as well as evaluations of the ecotoxicity of contaminants that can reach bodies of water. In water quality monitoring studies that include determination of richness, abundance and diversity in impacted environments the identified species may vary from one region to another, whereas in laboratory toxicity tests the species of the genera Tetrahymena and Paramecium are internationally most used . KEYWORDS: Protozoa. Ecotoxicity. Paramecium. Contaminants Protistas ciliados y su uso potencial como bioindicadores de la calidad del agua RESUMEN: La contaminacion de los ecosistemas acuaticos por los productos quimicos provenientes de las actividades agricolas inadecuadas y la descarga irregular de efluentes se ha intensificado. Por lo tanto, el uso de organismos que pueden indicar la presencia de estos contaminantes o la calidad de los cuerpos de agua es indispensable. El objetivo de este estudio fue realizar una revision de la literatura sobre los aspectos generales de los protistas ciliados que enfatizan la importancia de usar estos organismos como indicadores biologicos en estudios de monitoreo de calidad del agua y las pruebas de ecotoxicidad con los contaminantes acuaticos. De acuerdo con esta encuesta, los protistas ciliados son excelentes organismos para ser usados como bioindicadores de la calidad del agua en los programas de vigilancia debido a su abundancia, corto ciclo de vida, sensibilidad a los cambios biologicos en el medio ambiente acuatico fisica, quimica y facilidad de mantenimiento, laboratorio y prevalencia en los cuerpos de agua. Los estudios con estos ciliados pueden centrarse tanto en el analisis de la diversidad, riqueza y abundancia de las especies en los ecosistemas acuaticos como las evaluaciones de la ecotoxicidad de los contaminantes que pueden llegar a los cuerpos de agua. En los estudios de vigilancia de la calidad del agua, incluyendo la determinacion de la riqueza, abundancia y diversidad de ambientes impactos especies identificadas pueden variar de una region a otra, mientras que en el laboratorio de pruebas de toxicidad de especies de generos Tetrahymena y Paramecium son los mas utilizados a nivel internacional . PALABRAS-CLAVE: Protozoos. Ecotoxicidad. Paramecium. Contaminantes.