Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-07-29T12:59:33Z No. of bitstreams: 1 2011 - Tatiana Salom?o Barbosa.pdf: 562866 bytes, checksum: 6cdcd52bb7ab78c9cb4b4a47f918a85c (MD5) / Made available in DSpace on 2016-07-29T12:59:33Z (GMT). No. of bitstreams: 1 2011 - Tatiana Salom?o Barbosa.pdf: 562866 bytes, checksum: 6cdcd52bb7ab78c9cb4b4a47f918a85c (MD5) Previous issue date: 2011-02-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior- CAPES. / BARBOSA, Tatiana Salom?o. Mycological and mycotoxicological evaluation of feed supplied in the diet of tilapias in breeding. 2011. 37 p. Dissertation (Master?s Degree in Science and Technology of Food). Technology Institute, Federal Rural University of Rio de Janeiro, Serop?dica, RJ, 2011. Pisciculture is a specific branch of aquaculture aimed at raising fish in captivity. For its great advantages tilapia stand out as the queens of modern pisciculture and its cultivation has been pointed out by experts as a promising activity in the world and especially in Brazil due to its potential hydrological, climatic conditions and excellent satisfactory production of grains used in manufacturing ration. It is known these grains are highly susceptible to fungal contamination with possible formation of mycotoxins, and this constitutes a major problem worldwide. Among the genera evolved in mycotoxins production is Aspergillus, Penicillium e Fusarium. The most prevalent mycotoxins are aflatoxins, ochratoxin A, fumonisins, zearalenone and trichothecenes. These are substances capable of affecting the productivity with serious economic losses and risks to animal and human health. Then, this study aimed to determine the water activity and the total contaminant mycoflora, to establish the occurrence of species potentially mycotoxin-producing belonging to the genera Aspergillus, Penicillium and Fusarium, to determine the presence of aflatoxin B1, ochratoxin A, fumonisin B1 and to characterize mycotoxins profile of toxigenic strains isolated from feed supplied in the diet of tilapia in piscicultures. ,Samples (60) were collected from commercial feed directly from the fish-farming properties in Central and South regions of Rio de Janeiro. Water activity was measured . The total mycoflora was determined by serial decimal dilution plate and fungal colonies were identified at genera level. The identification of Aspergillus spp. and Penicillium spp. followed specific taxonomic keys. The profile was conducted to toxigenic strains potentially ochratoxin A and aflatoxin B1 producers isolated from the samples. The determination of the natural incidence of ochratoxin A and aflatoxin B1 was performed by thin layer chromatography and fumonisin B1 was determined by ELISA kits. Data were submitted to analysis of variance (ANOVA) and comparisons of means by Tukey's test (p < 0.05). The average of the aW of the samples was 0.61 ? 0.041 in the Central Region and 0.58 ? 0.060 in the South, both below the value considered optimal for fungal growth and mycotoxin production. Mean levels of fungal contamination were 1.0 x 103 CFU g-1 in the Central and 4.7 x 103 CFU g-1 in the South region, being within the recommended standards for international Good Manufacturing Practice for feed, which is 1.0 x 104 CFU g-1 The most isolated genera were Cladosporium (85%), Aspergillus (68%) and Penicillium (60%). The most frequent species were P. citrinum (31%), A. niger aggregate (21%) and A. flavus (20%). All isolates of A. niger aggregate were negative for the capacity to produce ochratoxin A. Among the A. flavus strains, 16% were positive for the production aflatoxin B1. Concerning the natural incidence of mycotoxins, the samples had detectable levels of fumonisin B1 (98%), aflatoxin B1 (55%) and ochratoxin A (2%). The detection of mycotoxins in almost all the feed samples analyzed highlights the need to implement good agriculture and manufacturing practices, in order to ensure the safety of feed and to reduce the risk of mycotoxicosis occurrence. / BARBOSA, Tatiana Salom?o. Avalia??o micol?gica e micotoxicol?gica de ra??es fornecidas na dieta de til?pias em criat?rios. 2011. 37 p. Disserta??o (Mestrado em Ci?ncia e Tecnologia de Alimentos). Instituto de Tecnologia, Universidade Federal Rural do Rio de Janeiro, Serop?dica, RJ, 2011. A piscicultura ? um ramo espec?fico da aq?icultura voltada para a cria??o de peixes em cativeiro. Por suas grandes vantagens as til?pias se destacam como as rainhas da piscicultura moderna e seu cultivo vem sendo apontado por especialistas como promissora atividade no mundo e principalmente no Brasil em decorr?ncia do seu potencial hidrogr?fico, condi??es clim?ticas excelentes e produ??o satisfat?ria de gr?os utilizados na fabrica??o de ra??o. Sabese que estes gr?os s?o altamente suscept?veis ? contamina??o f?ngica com poss?vel forma??o de micotoxinas, o constitui um problema de grande import?ncia em n?vel mundial. Dentre os g?neros f?ngicos envolvidos na produ??o de micotoxinas destacam-se o Aspergillus, Penicillium e Fusarium. As micotoxinas de maior preval?ncia s?o as aflatoxinas, ocratoxina A, fumonisinas, zearalenona e tricotecenos. Estas s?o subst?ncias capazes de afetar os par?metros produtivos, com graves perdas econ?micas e riscos para a sa?de animal e humana. Assim, este estudo objetivou determinar a atividade de ?gua e a micobiota total contaminante, estabelecer a ocorr?ncia de esp?cies potencialmente produtoras de micotoxinas pertencentes aos g?neros Aspergillus, Penicillium e Fusarium, determinar a presen?a de aflatoxina B1, ocratoxina A e fumonisina B1 e caracterizar o perfil tox?geno de cepas de esp?cies isoladas de amostras de ra??es fornecidas na alimenta??o de til?pias provenientes de pisciculturas. Para isto, foram coletadas 60 amostras de ra??es comerciais diretamente das propriedades piscicultoras nas regi?es Centro e Sul do Estado do Rio de Janeiro. As amostras tiveram sua atividade de ?gua aferida. Em seguida, a micobiota total foi determinada pelo m?todo de dilui??o decimal seriada em placa. Depois de isoladas, as col?nias foram identificadas em n?vel de g?nero. A identifica??o de Aspergillus spp. e Penicillium spp. seguiu chaves taxon?micas espec?ficas. O perfil tox?geno foi realizado para as cepas potencialmente produtoras de ocratoxina A e de aflatoxina B1 isoladas das amostras. A determina??o da incid?ncia natural destas micotoxinas foi realizada atrav?s de cromatografia em camada delgada. A determina??o da presen?a de fumonisina B1 nas amostras foi feita atrav?s de kits ELISA. Os resultados foram submetidos ? an?lise de vari?ncia (ANOVA) e compara??o de m?dias pelo teste de Tukey (p < 0,05). A m?dia obtida da Aa das amostras foi de 0,61 ? 0,041 na Regi?o Centro e de 0,58 ? 0,060 na Regi?o Sul, ambas abaixo do valor considerado ?timo para o crescimento f?ngico e produ??o de micotoxinas. Os n?veis m?dios de contamina??o f?ngica foram de 1,0 x 103 UFC g-1 no Centro e de 4,7 x 103 UFC g-1 no Sul do Estado, ficando dentro dos padr?es recomendados pelas Boas Pr?ticas de Fabrica??o internacional para a alimenta??o animal, que ? de 1,0 x 104 UFC g-1 de amostra. Os g?neros f?ngicos mais isolados foram Cladosporium (85%), Aspergillus (68%) e Penicillium (60%). As esp?cies mais freq?entes foram P. citrinum (31%), A. niger agregados (21%) e A. flavus (20%). Todas as cepas isoladas de A. niger agregados foram negativas para o teste de capacidade produtora de ocratoxina A. Dentre as cepas de A. flavus isoladas, 16% foram positivas para a produ??o de aflatoxina B1. Quanto ? incid?ncia natural de micotoxinas, 98% das amostras apresentaram n?veis detect?veis de fumonisina B1, 55% de aflatoxina B1 e 2% de ocratoxina A. A detec??o de micotoxinas em quase todas as amostras de ra??o analisadas ressalta a necessidade de implanta??o de boas pr?ticas de agricultura e de fabrica??o, a fim de se garantir um alimento mais seguro e reduzindo os riscos da ocorr?ncia de micotoxicoses.