ABSTRACT
Some bacteria and fungi are related to deterioration and also transmission of foodborne diseases, emphasizing the need to search new substances that may act in the treatment and prevention of the illnesses transmitted by food. Strains from genus Bacillus produce a variety of substances with inhibitory activity that range from antibiotics to bacteriocins. In this work, three strains, identified as B. pasteurii (Pes1) and B. insolitus (Mam2 and Ame3) presented inhibitory action against staphylococcal strains isolated from food. Out of the 33 strains tested, 31 (94.0%) were inhibited by at least one of three main Bacillus producer strains, being most of them inhibited by strain Pes1, that also was able to inhibit filamentous fungi related to food spoilage. The antimicrobial substances produced by Pes1, Mam2 and Ame3 showed to be resistant to proteolytic enzymes, suggesting these substances have not an active proteinaceous compound, as typical bacteriocins. New studies are being performed to extract and characterize these antimicrobial agents to evaluate their potential application in biological control of microorganisms related to spoilage food and foodborne diseases.
ABSTRACT
Avaliou-se o desenvolvimento de Muscina stabulans (Diptera, Muscidae) após exposição ao fungo Metarhizium anisopliae (isolado CG34), sob condições de laboratório. Suspensões de esporos foram preparadas nas concentrações de 10(5), 10(6), 10(7) e 10(8)conídeos/mL-1. Noventa larvas pós-alimentar por tratamento, distribuídas em cinco tratamentos e três repetições, foram mergulhadas por um segundo nas respectivas suspensões, transferidas para placas de Petri com papel filtro umedecido e mantidas em estufa BOD à temperatura de 25ºC, umidade relativa de 80 por cento e fotoperíodo de 12:12 horas até a emergência dos adultos. Foram avaliados a taxa de mortalidade pupal e o período de desenvolvimento pupal. As larvas apresentaram suscetibilidade à ação de M. anisopliae em diferentes concentrações. A mortalidade pupal assim como o tempo de desenvolvimento das pupas (de 8,8 a 10 dias) aumentaram conforme o aumento da concentração de conídios (de zero a 47 por cento). A aplicação de M. anisopliae nesta fase do ciclo biológico comprometeu o desenvolvimento de M. stabulans e interferiu no controle natural de pragas que se desenvolvem no mesmo ambiente.
The development of Muscina stabulans (Diptera, Muscidae) after exposure to Metarhizium anisopliae (CG34 isolated) fungi under laboratory conditions was evaluated. Suspensions of spores were prepared in concentrations of 10(5), 10(6), 10(7), and 10(8)conidia/mL-1. Ninety postfeeding larvae per treatment, divided into five treatments and three repetitions, were dived for one second in the respective suspensions, and transferred to Petri dishes with humidified filter paper and maintained in BOD at 25 ºC with 80 percent relative humidity and a 12:12h photoperiod, until the emergency of adults. The rate of pupal mortality and the period of pupal development were evaluated. The larvae showed susceptibility to the action of M. anisopliae in different levels of concentration. The pupal mortality increased accordingly to the increase in the conidia concentration (from zero to 47 percent), as well as prolonged the time of development of the pupae (from 8.8 to 10 days). The application of M. anisopliae in this phase of the biological cycle compromised the development of M. stabulans and interfered in the natural control of pests that develop in the same environment.
Subject(s)
Animals , Metarhizium/pathogenicity , Muscidae/growth & development , Mortality , Pest Control, BiologicalABSTRACT
O objetivo deste trabalho foi conhecer a diversidade de artrópodes associada ao cultivo de Pleurotus sajor-caju em palha de arroz pasteurizada em ambiente semicontrolado, localizado no sul do Rio Grande do Sul. A captura dos espécimes foi realizada no período de abril a maio de 2007, durante a fase de frutificação da cultura, compreendendo 45 dias. Foram realizadas nove coletas com intervalos de 5 dias, utilizando armadilhas INTRAL AL 012 (12 volts). Capturou-se um total de 3.129 indivíduos divididos em cinco ordens com predominância de Diptera (2.874), Hymenoptera (152), Ortoptera (69), Colembola (59) e Coleoptera (38). A ordem Diptera foi a que apresentou o maior número de famílias, sendo Mycetophilidae (2.530), Sciaridae (264), Cecidomyiidae (10), Phoridae (46), Muscidae (4), Calliphoridae (1) e Culicidae (19).
The objective of this research was to know the diversity of arthropods associated to the Pleurotus sajor-caju crop in rice straw pasteurized in a semicontrolled environment, located in the south of the state of Rio Grande do Sul, Brazil. The capture of specimens was carried out in the period of April through May 2007, during the phase of fruit bodies of the crop, lasting 45 days. Nine collections with intervals of 5 days were carried out, using INTRAL AL 012 (12 volt) traps. A total of 3129 individuals divided into five orders with predominance of Diptera (2874), Hymenoptera (152), Ortoptera (69), Colembola (59) and Coleoptera (38) was captured. The Diptera order was the one that presented the biggest number of families, being Mycetophilidae (2530), Sciaridae (264), Cecidomyiidae (10), Phoridae (46), Muscidae (4), Calliphoridae (1) and Culicidae (19).