Efeito combinado de carvacrol e tiabendazol contra Colletotrichum gloesporioides, Fusarium solani e Alternaria alternata / Combined effect of carvacrol and thiabendazole against Colletotrichum gloesporioides, Fusarium solani and Alternaria alternata

O objetivo deste trabalho foi determinar a atividade antimicrobiana do carvacrol e sua combinação com tiabendazol no controle de fungos patogênicos deteriorantes de frutas (Colletotrichum gloesporioides, Fusarium solani e Alternaria alternata). O carvacrol apresentou uma concentração inibitória mínima (CIM) de 282 a 563 μg mL-1 para os fungos testados. Quando avaliado em conjunto com o tiabendazol apresentou efeito aditivo contra C. gloesporioides e F. solani (FICI 0,5 e 1,0, respectivamente) e sinérgico contra a A.alternata (FICI 0,1). Houve redução da CIM do carvacrol de 50 a 88%. Este estudo mostra o potencial do uso.

ß-Glucanase Addition in Brewing Malt Produced by Reduced Time of Germination

Abstract The β-Glucans content has straight influence on the quality of malt and beer, mainly during the filtration step. Barley presenting high β-Glucan content demands longer germination time at malting. The application of commercial β-Glucanase is an alternative to accelerate the process and preserve the quality of malt. This work aimed to evaluate the effect of commercial β-Glucanase addition in malt produced within reduced germination time (64 h). Micro-malting was conducted with BRS-Caue and Elis barley cultivars at germination time 64 h and 96 h. The β-Glucanase concentration applied were 0, 25, 50 and 100 mg.kg-1. Barley, malt and wort samples were analyzed to check their physical-chemical features. Beers were produced with BRS-Caue malt and the physical-chemical and sensory attributes were analyzed. The commercial enzyme addition in BRS-Caue and Elis (64 h), at concentration 25 and 50 mg.kg-1, resulted in wort presenting proper β-Glucan content (≤ 178 mg.L-1). The beer produced with malt germinated for 64 h and added with 50 mg.kg-1 of β-glucanase was the one showing the largest number of physical-chemical and sensory parameters similar to the beer made with malt germinated for 96 h (conventional process). Commercial β-glucanase application in malt allowed accelerating the malting process without affecting the quality of the malt for beer production.

Biomonitoring of microcystin and aflatoxin co-occurrence in aquaculture using immunohistochemistry and genotoxicity assays

This work investigated the effects of co-occurring aflatoxin B1 (AFB1) and microcystin (MC) in aquaculture, using immunohistochemistry and genotoxicity methods. Tilapia (Oreochromis niloticus) were exposed to AFB1 by intraperitoneal and MC (cell extract of Microcystis aeruginosa) by intraperitoneal and immersion routes. The interaction of MC-AFB1 was evaluated co-exposing the intraperitoneal doses. Blood samples were collected after 8, 24, and 48h to analyze the micronucleus frequency and comet score. The interaction of MC-AFB1 showed a synergic mutagenic response by higher micronucleus frequency of co-exposed group. A slight genotoxic synergism was also observed in the comet score. Immunohistochemistry detected MC in al lthe fish liver tissues exposed to MC by intraperitoneal route, and only the immersed group with the highest dose of MC showed a positive response. Although MC was non-detectable in the edible muscle, the combination of immunohistochemistry with genotoxicity assay was an attractive biomonitoring tool in aquaculture, where the animals were frequently exposed to co-occurring synergic hazards.

Imunoistoquímica: detecção de microcistina em tilápia exposta ao extrato de Microcystis aeruginosa (Cyanobacteria) / Imunohistochemistry: detection of microcystin in tilápia exposed to Microcystis aeruginosa (Cyanobacteria) extract

A deterioração da qualidade de água pela piscicultura associa-se à eutrofização, com florescimento de cianobactérias. Microcystis aeruginosa destaca-se como principal produtora de microcistinas (MCs), grupo de hepatotoxinas com potencial promotor de tumor. No presente trabalho desenvolveu-se método imunoistoquímico para a detecção de MC em tilápias (Oreochromis niloticus) submetidas à injeção intraperitoneal (i.p.) ou imersão em extrato de M. aeruginosa BCCBUSP 262, empregando anticorpo monoclonal anti-MC (M8H5) e sistema polímero-peroxidase. As tilápias (N=42) foram submetidas a sete tratamentos, sendo três grupos inoculados i.p. com 2,0x105, 4,0x105 e 1,0x106 cels.Kg-1 de M. aeruginosa BCCBUSP 262 e quatro submetidos à imersão em diferentes concentrações do extrato da cianobactéria (variando de 1,0x104 a 1,0x105cel.mL-1). Analisando fígado e tecido muscular pelo ensaio imunoistoquímico, não se detectou marcação em tecido muscular. Todos os animais inoculados i.p. apresentaram marcação positiva para MC no fígado, mas em teste de imersão, apenas os expostos a maior dose (1,0x105 cels.mL- 1) apresentaram marcação positiva. Embora MC não seja detectada em tecido muscular, assim como no fígado de animais imersos em extrato de M. aeruginosa CCBUSP 262 em concentrações menores que 1,0x105 cels.mL-1, os resultados constituíram-se base para o desenvolvimento metodológico objetivando a aplicação da imunoistoquímica no diagnóstico rápido no controle de qualidade de pescados.

The deterioration of the water quality due to aquaculture is associated with eutrophication, with bloom of cyanobacteria. Microcystis aeruginosa is distinguished as main producer of microcystins (MCs), group of hepatotoxins with tumor promoter potential. In the present work immunohistochemical method for detection of MC in tilápia (Oreochromis niloticus), fish submitted to intraperitoneal injection (i.p.) or immersion in extract of M. aeruginosa BCCBUSP 262 was developed, using monoclonal antibody anti- MC (M8H5) and polymer peroxidase system. The tilápias (N=42) had been submitted to the seven treatments, three groups inoculated i.p. with 2.0x105, 4.0x105 and 1.0x106 cells. Kg-1 of M. aeruginosa BCCBUSP 262 and four groups exposed to the immersion in different extract concentrations of cyanobacterium. Analyzing liver and muscular tissue for immunohistochemical assay, muscular tissue was not stained. All the animals inoculated i.p. presented positive marking for MC in the liver, but in immersion test, only the ones exposed in the highest dose (1,0x105 cels.mL-1) presented positive marking. Although MC was not detected in muscular tissue, as well as in the liver of animals immersed in extract of M. aeruginosa BCCBUSP 262 in concentrations less than 1.0x105 cels.mL-1, the results would constitute in the base for the methodological development aiming the application of the immunohistochemistry in the rapid diagnosis in quality control of fish.