RESUMO
An acid phosphatase from Trichoderma harzianum was purified in a single step using a phenyl-Sepharose chromatography column. A typical procedure showed 22-fold purification with 56% yield. The purified enzyme showed as a single band on SDS-PAGE with an apparent molecular weight of 57.8 kDa. The pH optimum was 4.8 and maximum activity was obtained at 55 degrees C. The enzyme retained 60% of its activity after incubation at 55 degrees C for 60 min. The K (m) and V (max) values for p-nitrophenyl phosphate (p-NPP) as a substrate were 165 nM and 237 nM min(-1), respectively. The enzyme was partially inhibited by inorganic phosphate and strongly inhibited by tungstate. Broad substrate specificity was observed with significant activities for p-NPP, ATP, ADP, AMP, fructose 6-phosphate, glucose 1-phosphate and phenyl phosphate.
Assuntos
Fosfatase Ácida/isolamento & purificação , Fosfatase Ácida/metabolismo , Trichoderma/enzimologia , Eletroforese em Gel de Poliacrilamida , Concentração de Íons de Hidrogênio , Especificidade por Substrato , TemperaturaRESUMO
Acid phosphatases (ACPases) are produced by a variety of fungi and have gained attention due their biotechnological potential in industrial, diagnosis and bioremediation processes. These enzymes play a specific role in scavenging, mobilization and acquisition of phosphate, enhancing soil fertility and plant growth. In this study, a new ACPase from Trichoderma harzianum, named ACPase II, was purified and characterized as a glycoprotein belonging to the acid phosphatase family. ACPase II presents an optimum pH and temperature of 3.8 and 65 °C, respectively, and is stable at 55 °C for 120 min, retaining 60% of its activity. The enzyme did not require metal divalent ions, but was inhibited by inorganic phosphate and tungstate. Affinity for several phosphate substrates was observed, including phytate, which is the major component of phosphorus in plant foods. The inhibition of ACPase II by tungstate and phosphate at different pH values is consistent with the inability of the substrate to occupy its active site due to electrostatic contacts that promote conformational changes, as indicated by fluorescence spectroscopy. A higher affinity for tungstate rather than phosphate at pH 4.0 was observed, in accordance with its highest inhibitory effect. Results indicate considerable biotechnological potential of the ACPase II in soil environments.
Assuntos
Fosfatase Ácida/biossíntese , Biotecnologia/métodos , Proteínas Fúngicas/biossíntese , Trichoderma/enzimologia , Fosfatase Ácida/química , Proteínas Fúngicas/química , Glicosilação , Concentração de Íons de Hidrogênio , Microbiologia Industrial/métodos , Fosfatos/química , Conformação Proteica , Espectrometria de Fluorescência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Eletricidade Estática , Temperatura , Compostos de Tungstênio/químicaRESUMO
Investigações epidemiológicas demonstram que parasitoses intestinais apresentam alta prevalência em países em desenvolvimento e que a ingestão de hortaliças contaminadas por dejetos humanos é uma das principais vias de transmissão dessas infecções. Existem poucas pesquisas sobre o controle de contaminação alimentar e, como o Brasil é um país com condições precárias de saneamento, cuidados com a produção e o manuseio de alimentos, especialmente os que são ingeridos crus, devem ser intensificados. O objetivo deste trabalho foi determinar qualitativamente a presença de formas evolutivas de enteroparasitas, em alfaces comercializadas em Anápolis-GO. Para análise foram utilizadas 62 amostras de alface crespa (Lactuva sativa) de cultivo tradicional e 17 de cultivo hidropônico. Todas foram adquiridas aleatoriamente durante os meses de Setembro de 2009 a Janeiro de 2010 sendo 39 em diversos supermercados, 20 em feiras livres e 20 em sacolões de diferentes regiões da cidade. A análise mostrou a presença de enteroparasitos em todas as amostras, o que evidencia as más condições sanitárias de produção, provavelmente pela contaminação da água usada no cultivo
Epidemiological investigations have shown that intestinal parasites are highly prevalent in developing countries. The ingestion of vegetables contaminated by human waste is a major route of transmission of these infections. There is little research on strategies for control of food contamination and, as Brazil is a country with poor sanitation, care of the production and handling of foods, especially those eaten raw, should be intensified. The aim of this study was to determine qualitatively the presence of evolutionary forms of intestinal parasites in lettuce sold in Anápolis- GO. For analysis were used 62 samples of lettuce (Lactuva sativa) from traditional cultivation and 17 from hydroponic cultivation. All were acquired at random during the months of September 2009 to January 2010, with 39 samples from several supermarkets, 20 in free markets and 20 in retail shops in different parts of town. The analysis showed the presence of intestinal parasites in all samples, indicating poor sanitary in the production, probably due to water contamination used in the cultivation. Anápolis is a great city and presents good socioeconomic conditions, however, relevant measures should be taken by relevant agencies to try will better sanitation