Orientador: Ana Marisa Fusco-Almeida / Coorientador: Francisco Javier Enguita / Banca: Eloisa aparecida Mocheuti Kronka / Banca: Daniel Guariz Pinheiro / Banca: Eleini Gomes / Banca: Tais Maria Bauab / Resumo: O processo de fermentação é amplamente utilizado em usinas brasileiras para produção de bioetanol e, mesmo sendo um processo amplamente difundido, a problemática sobre contaminações por micro-organismos ainda é uma incógnita. Problemas de redução de produtividade estão diretamente ligados à competição de nutrientes quando há decorrentes crises de contaminações por bactérias e leveduras não-Saccharomyces. Entre as leveduras contaminantes mais encontradas estão as pertencentes aos gêneros Candida, Torulopis, Rhodotorula, Pichia, Komagataella e Schizosaccharomyces. Muitos antimicrobianos são utilizados para combater contaminações, porém com baixas especificidade e eficiência para leveduras contaminantes. O desenvolvimento de novas alternativas para a descontaminação do processo fermentativo e a busca por biomoléculas naturais e não geradoras de resíduos tóxicos, são emergenciais. Tais biomoléculas podem ser originárias dos miRNAs, que são pequenas moléculas de RNA não codificantes que afetam a estabilidade dos RNAs mensageiros, atuando na expressão de transcritos dentro de processos biológicos, afetando controles transcricionais e pós-transcricionais, resultando na inibição ou potencialização da ação gênica nos processos biológicos fermentativos. Dessa forma, miRNAs livres na dorna de fermentação podem interferir de maneira controlada os contaminantes que competem com a levedura Saccharomyces cerevisiae na produção de bioetanol. Em estudos anteriores de nosso grupo foi seleciona... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The fermentation process is widely used in Brazilian plants for the production of bioethanol and, even though it is a widely diffused process, the problem of contamination by microorganisms is still unknown. Productivity reduction problems are directly linked to nutrient competition when there are bouts of contamination by bacteria and non-Saccharomyces yeasts. Among the most common contaminating yeasts are those belonging to the genera Candida, Torulopis, Rhodotorula, Pichia, Komagataella and Schizosaccharomyces. Many antimicrobials are used to combat contamination, but with low specificity and efficiency for contaminating yeasts. The development of new alternatives for the decontamination of the fermentative process and the search for natural biomolecules and non-toxic wastes are emergency. Such biomolecules may originate from the miRNAs, which are small molecules of non-coding RNA that affect the stability of messenger RNAs, acting on the expression of transcripts within biological processes, affecting transcriptional and post-transcriptional controls, resulting in the inhibition or potentiation of the gene action fermentative biological processes. Thus, free miRNAs in the fermentation dorna can interfere in a controlled manner the contaminants that compete with the yeast Saccharomyces cerevisiae in the production of bioethanol. In previous studies of our group, a contaminant strain of Candida tropicalis, isolated from a plant in the region of Araraquara/SP, was selected and studied, which persevered during the period of one harvest. As a continuity, our study aimed to elucidate the metabolic and transcriptional behavior of the relevant contaminant, C. tropicalis, during the fermentation cycle, through fermentative capacity techniques, sequencing of global RNA and to identify target genes for the development of miRNAs as antifungal biomolecules... (Complete abstract click electronic access below) / Doutor

Orientador: Sérgio Luís de Carvalho / Banca: Alessandro Minillo / Banca: Cristiano Poleto / Resumo: A contaminação dos ecossistemas aquáticos por compostos farmacológicos intensificou-se nos últimos anos devido ao aumento da produção e ao consumo desenfreado destas substâncias pela população. Estes compostos são encontrados em águas naturais e em efluentes de Estações de Tratamento de Esgoto (ETE), comprovando que sua presença em águas naturais é um indicativo de contaminação por águas residuárias de ETE. A presente pesquisa avaliou a ocorrência de compostos farmacológicos no Córrego da Onça, município de Três Lagoas (MS), bem como as relações específicas entre os pontos de monitoramento do corpo d'água. Assim, foram coletadas mensalmente, em um período de 12 meses amostras de água (1L) em seis pontos distintos representando diferentes seções do córrego. As amostras foram submetidas ao processo de extração em fase sólida e analisadas por cromatografia líquida de alta eficiência. Fármacos como atenolol, diclofenaco, ibuprofeno, naproxeno, paracetamol e piroxicam foram detectados nos pontos de coleta do corpo d'água. Com auxílio de uma ferramenta estatística, os pontos amostrais foram reunidos em duas classes, observando-se maior similaridade entre P1(Lagoa do Meio) e P2 (Lagoa Maior), e entre P4 (Jusante da ETE) e P5 (Novas Nascentes). Os resultados evidenciam a contaminação no córrego por compostos farmacológicos, possivelmente devido aos indícios de ligações clandestinas de esgoto sanitário e/ou não eficiência do sistema utilizado pela ETE do município de Três Lagoas. / Abstract: The contamination of aquatic ecosystems by pharmacological compounds has intensified in recent years due to increased production and consumption of these substances by population. These compounds are found in natural waters and effluents from sewage treatment plants (WTP), confirming that their presence in natural waters is indicative of contamination by wastewater from WTP. This study investigated the occurrence of pharmacological compounds in the Stream of Onça at TrêsLagoas (MS), and the specific relationships between the monitoring points of the waterbody. Water samples were collected monthly, over a period of 12 months (water samples 1L) at six different points representing different sections of the stream. The samples were subjected to the process of solid phase extraction and analyzed by high performance liquid chromatography. Drugs such as atenolol, diclofenac, ibuprofen, naproxen, paracetamol and piroxicam were detected in the sampling points of the waterbody. A statistical tool aided to divide the sites into two classes, with a greater similarity between P1 (Middle Pond) and P2 (Major Pond), and between P4 (Downstream of WTP) and P5 (New springs). The results show that the stream contamination by pharmacological compoundsis an indication of illegal connections of sanitary sewer and/or inefficiency of the system used by WTP of Três Lagoas (MS). / Mestre

[pt] Este trabalho tem por objetivo fazer uma avaliação das condições de contaminação, por hexaclorociclohexano (HCH), do subsolo da área da antiga fábrica de pesticidas, localizada na Cidade dos Meninos, Duque de Caxias. Pretende também caracterizar as condições hidrogeológicas básicas locais. Para isto foi feita amostragem de solo através de sondagens à percussão, utilizando-se um amostrador SPT adaptado, e instalados piezômetros para medições do nível d`água local, e realização de ensaios de permeabilidade. As amostras de solo foram analisadas através de cromatografia gasosa. / [en] The purpose of this work is to make an evaluation of the contamination by hexaclorociclohexane of the susbsoil, in a former pesticide factory area, sited in Cidade dos Meninos, Duque de Caxias. The basic hydrogeological conditions were also determined. The soil sampling was made by percussion drilling, using an adapted SPT sampler. Several piezometers were installed to make water level measurements and permeability tests. The soil samples were analised by gas chromatography.

Orientador: José Moacir Marin / Banca: Everlon Cid Rigobelo / Banca: Davi Rodrigo Rossato / Banca: Patrícia Amoroso de Andrade / Banca: Caroline Peters Pigatto de Nardi / Resumo: Escherichia coli de sorogrupo não- O157 produtora de Shiga toxina é reconhecida como causadora de sérias doenças em seres humanos. Entretanto, as pesquisas relacionadas à persistência das STEC não- O157 em solos agricultáveis são bastante limitadas. No presente estudo foi analisada a sobrevivência de E.coli genérica, E.coli portadora do gene eae e STEC não- O157 portadoras do gene stx1, stx2 e eae em dois solos agricultáveis, cultura de cana-de-açúcar e pastagem em duas situações diferentes, solos esterilizados por autoclavação e solo não autoclavado. As linhagens de E.coli foram inoculadas nos dois solos em ambas as situações em um sistema de microcosmo, o qual foi avaliado por 60 dias. Os resultados mostraram que todas as linhagens de E.coli foram recuperadas em menor número nos solos não autoclavados do que nos solos esterilizados por autoclavação. Também foi verificado que as linhagens STEC não- O157 sobreviveram por um período maior do que a linhagem de E.coli genérica no solo sob pastagem não autoclavado, no mínimo por 60 dias. Nós devemos prestar mais atenção ao longo período de sobrevivência das linhagens STEC não- O157 em solos de pastagem devido ao seu alto potencial de risco ao meio ambiente / Abstract: Shiga toxin producing Escherichia coli non- O157 serogroup has been recognized as cause of serious diseases in human. However, research on the persistence of STEC non- O157 in preharvest is limited. In the current study we analysed the survival behavior of generic E.coli, E.coli carrying eae gene and STEC non- O157 strain carrying stx1, stx2 and eae gene in two agricultural soils, sugar cane culture and grassland in two different situations autoclaved soil and non- autoclaved soil. The E.coli strains were inoculated in both soils in a microcosm system which was analysed for sixty days. Results showed that all E.coli strains were recovered in a smoller number in non- autoclaved soils than in the autoclaved soils. Also was verified that the STEC non- O157 strains survived longer than the generic E.coli strain in the non autoclaved grassland soil, at least for sixty days. We should pay more attention to the STEC non- O157 serogroup long survival in grassland soil and its potential environmental risk / Doutor

The contamination of 316L stainless steel surfaces within an electrospray ionisation source of a mass spectrometer is investigated. An accelerated method of contamination is used. Following initial test method development and investigation of the contamination resulting on the ion transfer components (sample cone, outer cone and extraction cone), flat samples are employed within the ionisation source. This enables characterisation of the contamination composition, morphology and build-up with time. Blood plasma is introduced into the mass spectrometer as it is a widely analysed substance that is known to result in contamination. The contamination from a mixture of human blood plasma, diluted in methanol, and a water/acetonitrile mobile phase is found to contain inorganic NaCl crystals embedded in a matrix of organic residues. The morphology shows self-organising features as the contamination builds. A model is proposed to explain the morphology, involving rapid evaporation of the droplets that impinge on the stainless steel surface. Two types of surface modification are considered for the stainless steel: electrochemically grown films and coatings deposited by vapour deposition. A method for electrochemical film growth is developed, enabling nanoporous films to be formed on the stainless steel in 5 M sulphuric acid at 60°C by square wave pulse polarisation between active or transpassive and passive potentials. The films are characterised using glow discharge optical emission spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, Rutherford backscattering spectroscopy and nuclear reaction analysis. The films are shown to be chromium- and molybdenum-rich relative to the substrate, and to consist mainly of sulphates, oxides and hydroxides. The morphology and composition of the films are discussed in relation to the polarisation conditions and mechanism of film formation. A range of vapour deposited coatings are considered: TiN, TiC, TiB2, Graphit-iC, and diamond-like carbon coatings with Si and N2 dopants and with varying sp2:sp3 ratios. In addition, a hydrophobic coating is deposited on the stainless steel by immersion, in order to provide a significant variation in surface energy. Surface analysis of the coatings is carried out, considering their sp2:sp3 ratios, their electrical conductivities, their water contact angle, and the various components of the surface energy. The contamination build-up on the surface of uncoated 316L stainless steel is compared with that on stainless steel with the various surface modifications. A method for quantification of the build-up of contamination on flat samples is developed using white light interferometry. The surface modifications which result in the slowest contamination build-up with time are then applied to the ion transfer components of the mass spectrometer. The robustness of the mass spectrometric response for the selected coated surfaces is compared with that of the uncoated stainless steel. The electrochemically grown films and two of the doped diamond-like carbon coatings are found to be successful in reducing the build-up of contamination.

Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-08-14T14:27:22Z No. of bitstreams: 1 AlannaOC_DISSERT.pdf: 1206940 bytes, checksum: 16d4953440e825979cbfcb54a963a7cd (MD5) / Made available in DSpace on 2017-08-14T14:27:22Z (GMT). No. of bitstreams: 1 AlannaOC_DISSERT.pdf: 1206940 bytes, checksum: 16d4953440e825979cbfcb54a963a7cd (MD5) Previous issue date: 2017-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The knowledge of the factors related to the dynamics of herbicides in the environment it’s fundamental importance to predict the behavior of herbicides in soils with different attributes and to the selection of suitable dosages, and to avoid detrimental effects on the environment and on subsequent crops. The use of plants can aid in the remediation of the contaminated soil, and the herbicide tolerance is an essential factor for the species used. The objective of this work was to evaluate the sorption and desorption for a better understanding of soil ametryn behavior and to select plant species for remediation programs in areas contaminated with the herbicide. In the determination of sorption and desorption, the “Batch Equilibrium” method was used to determine the equilibrium time of ametryn in eleven soils with different attributes. In the sorption test the ametryn solutions (0, 1, 2, 4, 8, 16, 24 and 32 mg L-1) prepared in CaCl2 0,01 mol L-1 were added 10mL to samples of 200g of soil, shaken for 4 hours. The Desorption was evaluated using tubes containing a concentration of 16 mg L-1 before the sorption test, to which were added 10 mL of the solution of CaCl2 0,01 mol L-1 without herbicide. All the supernatants were filtered and the concentration of the herbicide analyzed by high performance liquid chromatography. The selection of ametryn tolerant species was performed by means of two experiments. In the first one the tolerance of the twenty seven species was evaluated to half of the recommended dose of the herbicide (1.000 g ia ha-1). In the second experiment, the selected ones were submitted to three different doses of the herbicide (0, 1000 e 2000 g i.a ha-1). The results showed that the sorption was higher in soils with high organic matter content and higher ion exchange capacity.The ametryn caused the death of Leucaena leucocephala, Crotalaria juncea, Crotalaria ochoroleuca, Fagopyrum tataricum, Mimosa caesalpiniaefolia, Arachis pintoi, Crotalaria spectabilis, Pennisetum glaucum, Glycine max, Calopogonium mucunoides, Mucuna pruriens, Vigna unguiculata, Phaseolus vulgaris, Sesamum indicum e Gossypium hirsutum. Canavalia ensioformis was tolerant until to dose 1000 g i.a ha-1 of ametryn. Cajanus cajan and Brachiaria decumbens until to dose 2000 g i.a ha-1 and present potential for inclusion in the remediation program of this herbicide / O conhecimento dos fatores relacionados à dinâmica de herbicidas no ambiente é de fundamental importância para prever o comportamento destes em solos com diferentes atributos e para selecionar de dosagens adequadas, bem como evitar efeitos prejudiciais ao ambiente e às culturas subsequentes. O uso de plantas pode auxiliar no processo de remediação dos solos contaminados, sendo que a tolerância ao herbicida é fator essencial para a espécie utilizada. O objetivo deste trabalho foi avaliar a sorção e dessorção para o melhor entendimento do comportamento do ametryn no solo e selecionar espécies vegetais para programas de remediação de áreas contaminadas com o herbicida. Na determinação da sorção e dessorção foi utilizado o método “Batch Equilibrium” para determinar o tempo de equilíbrio do ametryn em sete solos com diferentes atributos. No ensaio de sorção foram adicionadas 10 mL das soluções de ametryn (0; 1; 2; 4; 8; 16; 24 e 32 mg L-1) preparadas em CaCl2 0,01 mol L-1 a amostras de 2,00g de solo, submetidas a agitação por 4 horas. A dessorção foi avaliada utilizando os tubos que continham a concentração de 16 mg L-1 antes do ensaio de sorção, a estes tubos foram adicionadas 10 mL da solução CaCl2 0,01 mol L-1 isenta de herbicida. Todos os sobrenadantes foram filtrados e a concentração do herbicida analisada por cromatografia liquida de alta eficiência. A seleção de espécies tolerantes ao ametryn foi realizada por meio de dois experimentos. No primeiro avaliou-se a tolerância das vinte e sete espécies a metade da dose recomendada do herbicida (1.000 g ia ha-1). No segundo experimento, as selecionadas foram submetidas a três doses diferentes (0, 1000 e 2000 g i.a ha-1) do herbicida. Os resultados demonstraram que a sorção foi maior em solos com alto teor matéria orgânica e maior capacidade de troca iônica, enquanto que a dessorção foi inversamente proporcional à sorção. O ametryn causou a morte de Leucaena leucocephala, Crotalaria juncea, Crotalaria ochoroleuca, Fagopyrum tataricum, Mimosa caesalpiniaefolia, Arachis pintoi, Crotalaria spectabilis, Pennisetum glaucum, Glycine max, Calopogonium mucunoides, Mucuna pruriens, Vigna unguiculata, Phaseolus vulgaris, Sesamum indicum e Gossypium hirsutum. Canavalia ensioformis foi tolerante até a dose 1000 g i.a ha-1 do ametryn e Cajanus cajan e Brachiaria decumbens até a dose 2000 g i.a ha-1 e apresentam potencial para inclusão em programa de remediação deste herbicida / 2017-08-14

Heavy metals are of great concern when released into the environment, especially at high concentrations. Because of their persistence and toxicity, they have the ability to impact organisms both directly and indirectly via bioaccumulation in the food chain. In this report the effects on aquatic insect composition and abundance as well as possible effects on metamorphosis from larvae to adults were examined in six lakes – three with elevated Zn and Pb concentrations and three reference lakes - situated in Arjeplog municipality. Aquatic larvae and adult aquatic insects were sampled one year apart, and the number of individuals and community composition of both life stages were compared. Contrary to my hypothesis, the results showed no significant differences in abundance, taxa richness or number of individuals in pollution sensitive taxa (EPT) due to contamination. However, the result showed that the effect of contamination on the number of insects is different at different life stages (larval or adult), with fewer adults than expected emerging from contaminated lakes. This is likely explained by detrimental effects, caused by high metal concentrations, obstructing metamorphosis and decreasing emergence success. In this study, the negative effects on emergence could foremost be observed in chironomids (Chironomidae), which was the most abundant insect taxon in both reference and contaminated sites. This leads to the conclusion that including effects on metamorphosis can provide useful insights when assessing effects of a contaminant on the health of freshwater ecosystems.

This research conducts a spatial and temporal analysis of the distribution of fecal coliform throughout the Capital Regional District (CRD) of southern Vancouver Island. The research is based on 17 years of historical data of stormwater samplings from 1995 to 2011 in the nearshore region. ArcGIS is used to map the fecal coliform data collected within and adjacent to nearshore areas to identify peaks above a regulated threshold. Heavily polluted areas are in Victoria downtown, Esquimalt and the southeastern shore of Oak Bay. Land-use data and drainage patterns are used to determine relationships between fecal coliform levels and land-use by considering relevant, temporally dependent factors. Temperature is positively correlated with FC level and precipitation is negatively correlated. The residential land use is identified as the main source of bacterial contamination. This analysis leads to a regression model that indicates two peaks (July and October) of FC level occur in a 12-month period and positively related to minimum temperature and cloud cover ratio. / Graduate

The purpose of this study was to evaluate different types of metal decontamination from waste water. Specifically, to evaluate water from the mire located at Slagnäs railway depot. Through a literature review from Swedish authorities and entrepreneurs regarding water remediation methods have been compiled and compared. Methods for waste water remediation are chemical methods, sedimentation and filtration. Standardized methods for decontamination are constantly updated with new materials and improved methods. Neither one of these methods are relevant on their own. The idea behind the experiment was to use Fenton reaction on the mire water which would contribute to precipitation of metals. Within the study an experiment with hydrogen peroxide and sodium hydroxide was performed. The idea behind the experiment was to use Fenton reaction on the mire water which would contribute to precipitation of metals. No conclusions can be drawn about hydrogen peroxide also known as Fentons reaction due to lack of analysis results. Trials with sodium hydroxide shown that the best results occur when pH is moderately adjusted at pH 6 and 7. Due to incomplete analytical results no conclusion about Fenton reaction as a waste water treatment method can be drawn based on this experiment. The lack of results is probably due to the continuous reaction between Fentons and organic matter.

VASCONCELOS, Elayne Cardoso de. Determinação da microbiota da carne ovina tratada com ácido acético, embalada à vácuo e maturada. 2000. 85 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-CE, 2000 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-02T13:23:17Z No. of bitstreams: 1 2000_dis_ecvasconcelos.pdf: 288719 bytes, checksum: e3069178e516b102c9f149e4370c0c0e (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-02T13:23:29Z (GMT) No. of bitstreams: 1 2000_dis_ecvasconcelos.pdf: 288719 bytes, checksum: e3069178e516b102c9f149e4370c0c0e (MD5) / Made available in DSpace on 2016-06-02T13:23:29Z (GMT). No. of bitstreams: 1 2000_dis_ecvasconcelos.pdf: 288719 bytes, checksum: e3069178e516b102c9f149e4370c0c0e (MD5) Previous issue date: 2000 / The objective of this study was to verify the effect of 1% acetic acid on the microbial condition of aged lamb meat. The experiment used five undefined breed (SRD) wethers, with 1 year of age. After slaughter the carcasses were chilled at 0ºC and kept for 12 h. Samples for microbiological analysis were collected from the surface of shoulder, neck, breast, loin, leg and the ventral side of the flank. These surfaces were evaluated for mesophiles and total and fecal coliform microrganisms. Shoulders were then separated from the carcass and cut to standard weight slices, from the proximal to the distal region of the cut. The right side shoulder slices were dipped in 1% acetic acid solution for 1 min and the left side shoulder slices were dipped in distilled water (control). The slices were individually vacuum packaged in a film, with low permeability to oxygen and then stored at 1ºC. On days 3, 13, 23, 33 and 48 of the aging period samples (5 trated with 1% acetic acid and 5 control) were collected, to be analyzed for total plate count, mould and yeast, sulfite-reduzing clostridia, total and fecal coliforms and Salmonella. There was no difference (P>0.05) in surface microrganism counts among different locations in the lamb carcass. Related to the aging of meat trated with acetic acid it was observed a decrease (P<0.05) in mesophiles count on trated samples with 13 and 23 days of aging. At 3 and 13 days of aging occurred a significant (P<0.05) decrease of psicrophylic organisms in meats treated with acetic acid. However at 23, 33 and 48 days of storage this effect was not observed. There were a decrease (P<0.05) in moulds and yeast counts is samples treated with acid. Mould andyeast counts were smaller (P<0.05) at day 13 than those at days 33 and 48 days of aging. Only at day 3 of aging treated samples showed lower (P<0.05) total coliform counts than samples with no acid. Meat samples treated with 1% acetic acid showed lower (P<0.05) fecal coliform counts than samples with no acid. It was observed absence of sulfite-reduzing clostridia in all samples independent of acid treatment or aging time. The presence of Salmonella detected in 20% of the treated samples and in 24% of the untreated ones. Meat pH values were lower (P<0.05) on days 3, 23 and 33 than on days 13 and 48 of aging. Results suggest that proper slaughter conditions in Northeast Brasil produce lamb carcasses with acceptable counts of microrganisms. Deeping of meat cuts in 1% acetic acid solution followed by vacuum packazing is appropriate to age meat at 1ºC for 13 days. This treatment keeps low levels of psicrofilic counts, allows a sound higienic condition of the meat but it is not enough to inhibit the presence of Salmonella. / O objetivo deste estudo foi verificar o efeito do ácido acético 1% sobre a microbiota da carne ovina maturada. Foram utilizados 5 animais ovinos machos castrados do tipo Sem Raça Definida (SRD), com idade aproximada de 1 ano, provenientes do interior do estado do Ceará. Após o abate as carcaças dos animais foram refrigeradas por 12 horas a 0ºC e em seguida foram coletadas amostras da superfície dos seguintes locais: paleta, pescoço, peito, lombo, coxão e cavidade abdominal. Nessas amostras foram realizadas análises microbiológicas de contagem padrão em placas de bactérias mesófilas, pesquisa de coliformes totais e fecais. As paletas foram então retiradas das carcaças e cortadas em fatias de peso similar, da porção proximal para a porção distal desse corte. As fatias das paletas direitas foram submetidas a tratamento de imersão em solução de ácido acético a 1% por 1 minuto e as fatias esquerdas foram imersas em água potável (controle). Todas as fatias foram em seguidas embaladas individualmente à vácuo em filme flexivel, impermeável ao oxigênio e armazenadas para maturação a 1ºC. Para as análises microbiológicas da carne de paleta, foram coletadas fatias nos dias 3, 13, 23, 33 e 48 de armazenamento. Em cada dia foram coletadas fatias, sendo 5 de cada tratamento de imersão. As análises realizadas foram contagem padrão em placa (mesófilos e psicrofilos), contagem de bolores e leveduras, contagem de clostridios sulfito-redutores, pesquisa de coliformes totais e fecais e pesquisa de Salmonella. Não houve diferenças significativas (P>0,05) na contagem de bactérias entre os diferentes locais da carcaça ovina analisada. Em relação ao estudo de armazenamento da carne, foi observada uma redução (P<0,05) da contagem de bactérias mesófilas nas carnes tratadas com ácido nos dias 13 e 23 de estocagem. Com 3 e 13 dias de armazenamento houve uma redução significativa (P<0,05) na microbiota de psicrófilos na carne da paleta ovina tratada com ácido. Entretanto nos dias 23, 33 e 48 de armazenamento esse comportamento não foi observado. Em relação a bolores e leveduras, houve uma redução (P<0,05) da microbiota das amostras tratadas em relação a das não tratadas. Este efeito foi evidente até o dia 13 de armazenamento. Somente no 3º dia de armazenamento, as amostras tratadas apresentaram contagens de coliformes totais significativamente (P<0,05) menores que as não tratadas. Tal comportamento, porém, não foi verificado nos dias 13, 23, 33 e 48 de estocagem. As amostras tratadas com ácido acético 1% apresentaram valores menores (P<0,05) de coliformes fecais do que as não tratadas. Observou-se ausência de clostrídios sulfito-redutores em todas as amostras, independente do tratamento e do tempo de maturação. A pesquisa de Salmonella, indicou presença deste microrganismo em 20 e 24%, das amostras tratadas com ácido acético 1% e não tratadas, respectivamente. Os valores de pH foram significativamente menores (P<0,05) nos dias 3, 23 e 33 que nos dias 13 e 48 de armazenamento. Os resultados sugerem que o abate cuidadoso de animais ovinos nas condições ambientais do Nordeste Brasileiro, permite obter carcaças com níveis aceitáveis de microrganismos na superfície. A imersão das carnes em ácido acético 1% seguida de estocagem a vácuo permite manter as carnes refrigeradas (1ºC) por 13 dias, com controle eficiente da microbiota deteriorativa, mantendo um padrão higiênico-sanitário adequado, mas não é suficiente para inibir o crescimento de Salmonella.