The development of a proanthocyanidin (PAC) treatment, along with the understanding of its mechanism of action, would provide an alternative method of preventing attachment to and colonization of surfaces by microorganisms, as well as potentially disrupting preexisting biofilms. The purpose of this research is to examine the role a cranberry proanthocyanidin plays in the primary attachment of Bacillus cereus to an abiotic surface. This technology could be employed in food processing plants where a premium is placed on maintaining a sanitized work environment to prevent product contamination. A biofilm assay showed that a surface treated with proanthocyanidins actually promoted rather than prevented the attachment of Bacillus cereus. This was further made evident by the fact that the surface hydrophobicities of B. cereus cells grown in media supplemented with proanthocyanidins were greater than those grown in its absence. In addition, light microscopy analysis showed a greater degree of sporulation of B. cereus cells when grown on TSA plates supplemented with PACs. These results suggest that proanthocyanidins may be inducing endospore formation in Bacillus cereus leading to increased attachment and surface hydrophobicity values.

L'objectiu principal del treball de recerca és aprofundir en el coneixement del grup de Bacteris Verds del Sofre (BVS) des del punt de vista de la relació amb la salinitat. L'estudi s'ha restringit als representants halotolerants o halòfils del grup amb tres línies de treball que corresponen a diferents àmbits de coneixement, com són la descripció del biòtop i la riquesa específica de les comunitats de BVS en els ambients naturals, l'avaluació de la significació taxonòmica de la capacitat de desenvolupament en ambients salins en el marc de discussió de la taxonomia-filogenètica del grup, i l'anàlisi de les estratègies fisiològiques desenvolupades per a l'osmoadaptació en medi salí. / The aim of this work is to extend the knowledge of Green Sulfur Bacteria (GSB), specifically those halotolerant and/or halophilic members of the group found in saline environments. The study has been carried out from three different perspectives, corresponding to different knowledge areas: describing the specific richness of GSB communities and environmentally relevant parameters of their habitats, evaluating the taxonomic significance of the requirements and tolerance of salts in the media and discussing the group's classification criteria, and analyzing the physiological responses developed for the osmoadaptation (in particular those related to the accumulation of compatible solutes) in saline media.

The O-acetylation of peptidoglycan (PG) is currently known to occur in greater than 50 eubacterial species, including numerous pathogens. This modification, which occurs at the C-6 hydroxyl of the N-acetylmuramoyl residues within the heteropolymer’s glycan backbone, serves as a cell wall autolytic regulatory mechanism, and contributes to pathogenesis and persistence within a host. Despite these significant physiological and pathobiological roles however, the identity of the pathway(s) responsible for the modification was only recently elucidated, for which two unrelated systems were identified, viz., the O-acetylpeptidoglycan (OAP) cluster-encoded multi-component system typical of Gram-negative species and the singular OatA of Gram-positives. As part of the OAP PG O-acetylation system, our group previously identified O-acetylpeptidoglycan esterase (Ape) as an enzyme responsible for the removal of the modification, permitting the continued metabolism of the PG sacculus. Herein, studies were performed to assess the postulated viability of this class of enzyme as a novel antibacterial target. Specifically, recombinant Ape1 from Neisseria gonorrhoeae was purified to homogeneity and the inhibitory effect of purpurin, a natural product identified as such, evaluated in detail. Kinetic analysis demonstrated that the compound elicited a competitive mode of inhibition (Kic ~3.7 μM), while the in vivo treatment of an array of environmental and pathogenic species was found to result in growth arrest for those cells containing both O-acetylPG and Ape. Evaluation of modification levels, cell wall morphology, and viability indicated a bacteriostatic effect. Taken together these data provide proof of principle that this class of enzyme presents a worthy therapeutic target. In addition to the presence of an Ape, the OAP system further differs from that of OatA through the use of two PG O-acetyltransferases. While purported to be mutually exclusive and evolutionarily divergent, in silico genomic analyses indicated their potential copresence in Bacillus anthracis and other closely related organisms. Indeed, purpurin-mediated differential growth inhibition between several such isolates and other bacilli indicated Ape activity therein. To investigate this possibility, the hypothetical Ape3 protein from Bacillus cereus ATCC 10987 was overproduced, purified, and its function assessed. Data from activity assays involving natural and synthetic substrates indicated that the protein possesses basal esterase activity in vitro. Phenotypic analysis of B. anthracis mutants deficient in each of the organism’s putative integral membrane PG O-acetyltranslocases subsequently indicated that Ape3 preferentially functions as a PG O-acetyltransferase (Pat) in vivo and that the OAP-mediated system is required for the separation of daughter cells following division. In addition, the presence of an Oat homologue was also confirmed. Thus, this is the first report of a bacterium known to possess both types of PG O-acetylation systems. / Natural Sciences and Engineering Research Council of Canada (NSERC)

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / Department of Biology

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv., 2007. / Härtill 5 uppsatser.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-05-04T14:05:26Z No. of bitstreams: 1 texto completo.pdf: 884943 bytes, checksum: 6d04675a5504c3d18ce512015afd015c (MD5) / Made available in DSpace on 2017-05-04T14:05:26Z (GMT). No. of bitstreams: 1 texto completo.pdf: 884943 bytes, checksum: 6d04675a5504c3d18ce512015afd015c (MD5) Previous issue date: 2005-04-26 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O Brasil é o principal produtor de feijão no mundo, com mais de três milhões de toneladas produzidas anualmente. Entretanto, esta produtividade poderia ser maior. Diversos fatores têm impedido que a produção do país aumente, entre eles, a ocorrência de doenças durante o ciclo da cultura tem papel central. Mais de duzentos patógenos já foram relatados ocorrendo em feijoeiro, embora apenas uma dúzia tenha sido relatada como importante. No Brasil, o crestamento bacteriano, a mancha angular, a ferrugem e a antracnose são as principais doenças da parte aérea da cultura, podendo reduzir a produção em até 70%. Atualmente, as medidas de controle adotadas têm sido relativamente eficientes devido à alta variabilidade dos patógenos no campo e pequeno número de genes de resistência disponíveis e o plantio das mesmas cultivares por ciclos sucessivos. Assim o controle biológico tem papel fundamental, quando inserido numa estratégia de manejo integrado de doenças. Dentre os organismos estudados para atuarem no biocontrole de doenças, as bactérias têm sido relatadas como capazes de inibir outros microrganismos por meio de mecanismos de antibiose, parasitismo, competição e indução de resistência. O presente trabalho teve como objetivos selecionar bactérias do filoplano de feijoeiro como agentes de biocontrole de doenças da parte aérea da cultura, baseado em estratégias de seleção conjuntas in vitro e in vivo, determinar que mecanismos de controle poderiam estar envolvidos, se os isolados obtidos estariam atuando como promotores de crescimento ou indutores de resistência e testar a efetividade dos isolados em campo, em diferentes cultivares e em idades diferentes da cultura, contra os patógenos desafiantes, Colletotrichum lindemuthianum, Erysiphe polygoni, Phaeoisariopsis griseola, Pseudomonas viridiflava, Uromyces appendiculatus e Xanthomonas axonopodis pv. phaseoli. Dos 500 isolados obtidos, três foram mais promissores, quanto ao controle das doenças em casa de vegetação, reduzindo a severidade das doenças quando comparados ao tratamento com água, sendo dois identificados por sequenciamento do RNA16S como Bacillus cereus (UFV-75 e UFV-172) e o terceiro, por análise de ácidos graxos, como Pseudomonas putida (UFV-108). Nos ensaios de antibiose in vitro, verificou-se que a bactéria Bacillus cereus (UFV-75) foi capaz de inibir, seja a germinação de conídios ou o crescimento micelial de fungos ou o crescimento de bactérias, todos os patógenos testados. Demonstrou-se em ensaio in vitro que B. cereus (UFV-75) foi produtor de sideróforos, compostos voláteis, bacteriocinas e da enzima quitinase. As bactérias B. cereus (UFV-172) e P. putida (UFV-108) também produziram sideróforos, embora o isolado UFV-172 não tenha inibido o crescimento de nenhum dos patógenos in vitro. Nos ensaios de campo, UFV-75, UFV-108 e UFV-172, reduziram a severidade da mancha angular (P. griseola) e da ferrugem (U. appendiculatus). Nos ensaios de promoção de crescimento, o isolado UFV-74 (Pseudomonas putida) foi selecionado, por promover o aumento do tamanho das folhas e das plantas em casa de vegetação e também aumentar a produtividade no campo, quando pulverizado sobre as folhas ou via microbiolização de sementes. Nos testes com produtos comerciais, B. cereus (os dois isolados) e P. putida foram sensíveis apenas aos fungicidas Cupravit Azul Br e Manzat 800. Nos ensaios de amplitude de controle, onde se avaliou a eficiência de B. cereus (UFV-172 e UFV-75) e P. putida, em controlar: a) o crestamento bacteriano em plantas da cultivar Pérola com idades diferentes; b) a antracnose, o oídio, a mancha bacteriana e a mancha angular na cultivar Pérola e; c) em nove cultivares diferentes contra o crestamento bacteriano, todos os três isolados foram eficientes em controlar o crestamento bacteriano comum em plantas com idades até 60 dias após a emergência. Todos os isolados foram capazes de reduzir a severidade da antracnose, do oídio, da mancha bacteriana e da mancha angular, exceto nos ensaios de UFV-75 X oídio e todos os isolados foram eficientes em controlar o crestamento bacteriano, em todas as cultivares testadas, exceto nos ensaios de UFV-75 X ‘Vermelhinho’. Nos ensaios de sistemicidade, onde buscava-se determinar se B. cereus (UFV-172) poderia estar atuando como indutor de resistência sistêmica, o isolado inibiu os patógenos desafiantes X. a. pv. phaseoli e M. incognita, quando aplicado em região separada espacialmente da região que foram aplicados os patógenos, dando indícios de que o isolado pode estar agindo nas plantas de feijoeiro como indutor de resistência. Esse resultado é corroborado pelo ensaio de restrição de multiplicação de X. a. pv. phaseoli, quando o isolado foi aplicado quatro dias antes do patógeno e esse, quando infiltrado em folhas de feijoeiro, teve um desenvolvimento inferior ao de plantas não expostas ao isolado, sugerindo que mecanismos de sinalização que induzem a síntese de compostos que restringem o desenvolvimento dos patógenos são desencadeados nas plantas quando estas são expostas ao isolado e que esse sinal é sistêmico sendo translocado das folhas até as raízes. / Brazil is the most important bean producer in the world, producing around 3 million tons of grains per year. Nevertheless, the Brazilian productivity could be higher but several factors have been impeding increases in productivity such as the occurrence of multiple diseases during the plant life cycle. In this sense, more than two hundred pathogens are known to induce diseases in bean but only a few actually are important. Under Brazilian conditions, the bacterial blight, the angular leaf spot, the rust and the anthracnose are the most important bean phylloplane diseases and may account for losses up to 70% if environmental conditions favor disease occurrence. Nowadays, the majority of disease control procedures lack efficiency due to inefficiency of available recommended chemicals in the field, the high level of variability in pathogen populations as well as the few resistance genes detected and manipulated. Therefore, biological control assumes paramount importance when included in global procedures of disease integrated management. Among focused microorganisms as potential biocontrol agents, bacteria have been exhaustively investigated and it is well known that they can act either by direct antibiosis or by inducing systemic resistance. This work had as main objective the selection of prokaryotic phylloplane residents that might act as agents of biological control for bean aerial part diseases, from a universe of 500 isolates obtained from healthy bean phylloplane. In this sense, the strategy of combining “in vitro” as “in vivo” procedures for the massal screen, the investigation on the nature of control mechanisms involved, specific tests to determine whether the observed biocontrol could be attributed to direct antibiosis or to induced resistance, specific assays to verify whether selected antagonists might act as growth promoters, field tests to investigate whether selected isolates would act as biocontrol agents when delivered to distinct bean cultivars, to plants in different phenology stages and against multiple pathogens (Xanthomonas axonopodis pv. phaseoli, Pseudomonas viridiflava, Uromyces appendiculatus, Colletotrichum lindemuthianum, Phaeoisariopsis griseola and Erysiphe polygoni) were studied. Out of the set of 500 isolates, three of them - UFV-75, UFV-172 (Bacillus cereus) and UFV-108 (Pseudomonas putida) – presented the best performance as biocontrol agents being able to reduce diseases severity up to 75% in greenhouse tests. In “in vitro” tests, isolate UFV-75 was able to inhibit growth of all pathogens as well as produce siderophores, volatile antimicrobial compounds, bacteriocins and chitinases. Isolates UFV-172 and UFV-108 also produced siderophores but the latter shown no “in vitro” activity against pathogens. In field trials, all three isolates showed efficiency for reducing severity of rust (U. appendiculatus) and angular leaf spot (P. griseola). In growth-promoting assays, an isolate distinct from the ones selected as biocontrol agents, namely UFV-74 (Pseudomonas putida), behaved as a good promoter, as detected by plant growth parameters evaluation like number of leaves, plant height and seed production, if delivered either by seed microbiolization or by spraying of propagules in the aerial part. Investigating the possibility of mixing the selected biocontrol agents and commercial products recommended in Brazil (registered pesticides, like fungicides, insecticides and herbicides) for the bean culture, it was found that all of them were sensitive only to the fungicides Cupravit Azul Br and Manzat 800. Using X. a. pv. phaseoli as challenging pathogen, it was found that all of them were able to low down disease severity but in the interaction isolate UFV-75 and “Vermelhinho” cultivar. All three selected isolates were able to promote the experimental biocontrol of bacterial blight under controlled conditions regardless plant age, up to 70 days after sowing. Using “Perola” as model cultivar, it was verified that protection brought about by the three isolates had character of multiplicity in the sense that this protection was effective against a broad range of pathogens like C. lindemuthianum, P. griseola P.viridiflava and Erysiphe polygoni. In protection sistemicity assays, the isolate UFV-172 provided protection against X. a. pv. phaseoli and Meloidogyne incognita even if delivered to locals remote from the site of inoculation. This constitutive sistemicity of protection indicates that isolate UFV-172 may promote biocontrol by inducing systemic resistance and the efficiency by which the antagonist restricted multiplication of a model pathogen (X. a. pv. phaseoli) in bean leaf tissue provided an additional evidence for that. / Tese importada do Alexandria

Consumer demand for fresher foods has necessitated the use of non-thermal technologies in processing milk. Two Dean Flow UV reactors (1/16" ID × 1/32" Thick & 1/8" ID × 1/32" Thick) were designed in the laboratory. The objective of this study was to examine the efficacy of designed UV reactors at four levels of Reynolds numbers (Re) on inactivation of Escherichia coli W 1485 cells and Bacillus cereus spores in raw cow milk (RCM), commercially processed skimmed cow milk (SCM) and raw soymilk (RSM). RCM, SCM and RSM were inoculated separately with E. coli W 1485 and B. cereus spores and were treated through the designed reactors for a residence time of 11.3 ± 0.1 s, equivalent to an UV dose of 0.05 J/ml in 1/16" ID reactor and 0.02 J/ml in 1/8" ID reactor. Four levels of Re were tested in the range of 181-1372. The influence of tube diameter (thickness of milk exposed to UV) and Re (indicator of turbulence) at constant residence time (11.3 ± 0.1 s) on inactivation of both the bacteria in both the UV reactors was analyzed using two-way ANOVA with proc GLM in SAS software. E. coli was inactivated to non-detectable levels (≥7.8 log10 CFU/ml) in SCM from the second level of Re (532.2) in 1/16" ID reactor. E. coli was also inactivated significantly (> 5logs) in RSM at the highest Re (1372) but this was not achieved in the case of RCM (712.7). Increasing the residence time to 14.2 s or greater (17 s) (equal to UV dose of 0.06 and 0.08 J/ml) inactivated E. coli cells to non-detectable levels in RCM using 1/16" ID reactor at the highest level of Re (712.7). Reduction of E. coli cells were in the range of 0.45-7.78 logs whereas B. cereus spores were in range of 1.06- 3.29 logs in all types of milk used in this study. The interaction effect of tube diameter and Re was statistically significant for E. coli cells in RCM, and SCM; B. cereus spores in SCM, and RSM (p < 0.05) whereas this was statistically non significant for E. coli cells in RSM and B. cereus spores in RCM (p > 0.05). Main effects of Reynolds number, and tube diameter were statistically significant (p < 0.05) on inactivation of B. cereus spores in RCM and E. coli cells in RSM. Inactivation efficiencies for both bacteria were higher in 1/16" ID reactor than 1/8" ID reactor. Using the 1/16" ID reactor at highest level of Re (RCM Re = 712.7, RSM Re = 1372), inactivation of standard plate count (SPC) present in RSM and RCM, and lipid oxidation during storage period (0, 1, 3 and 7 days) were measured. Inactivation of SPC in UV-treated RSM (3 logs) was lower than thermal pasteurization at 72°C for 20 s (7 logs). In case of RCM, the SPC was inactivated to 1.9 logs from 4.2 logs. Sensory evaluation (olfactory) of UV treated, untreated (milk passed through the 1/16" ID reactor while the UV lights turned off), and fresh RCM (control) suggested no change in flavor after treatment and upto 1 day after storage in refrigerated condition, but a perceivable change in the quality of UV treated and untreated cow milk were observed during the 3rd and 7th days when compared with fresh RCM (milked same day). RCM was treated with different UV dose levels (0.04, 0.05, 0.08, 0.12 and 0.16 J/ml) to examine the effect of UV light on malondialdehyde and other reactive substances using TBARS test kit. Reactive substances such as malondialdehyde content increased as the UV dose increased. The presence of malondialdehyde and other reactive substances were not significantly different (p < 0.05) in both thermal and UV-pasteurized soymilk; whereas these substances were found to be higher in UV-treated RCM after 7 days of storage than the untreated milk stored for 7 days at 4 °C and the fresh RCM. The designed reactors 1/16" ID and 1/8" ID reactors were useful to inactivate bacteria present in milk. But, the inactivation efficiency was more in 1/16" ID reactor than 1/8" ID reactor.

Made available in DSpace on 2014-12-17T14:16:26Z (GMT). No. of bitstreams: 1 IrisUM_DISSERT.pdf: 2435954 bytes, checksum: 34cd5bf96f0e9f5d42ed48a3b74595a4 (MD5) Previous issue date: 2011-02-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / O cacto Cereus jamacaru Mill. (Cactaceae) ? uma esp?cie t?pica da vegeta??o da caatinga. Sabe-se que os seus clad?dios cont?m os alcal?ides tiramina e 2- hidroxifeniletilamina, compostos ativos que podem atuar no sistema nervoso central, mimetizando a a??o da dopamina. Como essa esp?cie vegetal ? bastante utilizada na medicina popular, e n?o h? na literatura cient?fica nenhuma informa??o sobre os seus efeitos em esp?cies animais, maiores estudos s?o relevantes e necess?rios. No presente trabalho a an?lise fitoqu?mica (LC-MS/MS) identificou os alcal?ides D-tiramina (m/z 137,2), hordenina (m/z 165,2), N-metiltiramina (m/z 151) e ainda o amino?cido Dtirosina (m/z 181.2), precursor de diversos alcal?ides nos extratos etan?lico e aquoso obtidos de clad?dios de C. jamacaru. Os efeitos t?xicos e/ou comportamentais do extrato etan?lico nas doses de 210 e 420 mg/kg/dia, correspondentes respectivamente a 14 g e 28 g do p? da planta seca/kg/dia, foram investigados, em ratos. Os animais foram tratados durante trinta dias, por gavagem, quando ent?o foram submetidos a testes para avalia??o da atividade geral (campo aberto), do aprendizado e mem?ria (labirinto em cruz elevado modificado), do comportamento estereotipado induzido pelo femproporex e da catatonia induzida pelo haloperidol. Al?m disso, os par?metros de toxicidade (ganho de peso, consumo de ra??o e ingest?o h?drica), enzimas hep?ticas (ALT e AST), ureia e creatinina e histopatologia da adrenal, ba?o, cora??o, f?gado, p?ncreas e rim foram analisados. Os resultados mostraram diferen?as no consumo de ra??o e ingest?o h?drica pelos ratos machos e f?meas experimentais, com conseq?ente diminui??o do ganho de peso. O tratamento por 30 dias com a dose de 420 mg/kg/dia provocou aumento nas concentra??es de ur?ia e ALT dos machos e diminui??o na concentra??o do AST das f?meas, por?m a raz?o AST/ALT desses animais n?o foi estatisticamente diferente da raz?o dos animais do grupo controle, sugerindo aus?ncia de hepatotoxicidade. O estudo histopatol?gico n?o revelou nenhuma altera??o digna de nota nos diversos ?rg?os analisados. No campo aberto, tanto os machos como as f?meas experimentais, apresentaram atividade geral diminu?da em rela??o ao grupo controle. No labirinto em cruz elevado modificado observou-se uma tend?ncia (dados n?o significantes estatisticamente) de melhoria da mem?ria/aprendizado nos grupos experimentais de machos e f?meas em rela??o aos animais controle. No teste da catatonia, os machos experimentais tratados com a dose de 210 mg/kg/dia foram mais resistentes ? a??o do haloperidol, mostrando-se menos catat?nicos que os demais grupos. Nenhuma altera??o foi observada nas f?meas experimentais. N?o foi observada altera??o alguma no comportamento estereotipado dos animais experimentais machos e f?meas. Esses resultados sugerem que a exposi??o de ratos ao extrato etan?lico de C. jamacaru produz efeitos t?xicos e afeta os par?metros comportamentais avaliados em ratos machos e f?meas de maneiras diferentes. Poss?vel prote??o estrog?nica e/ou diferen?as na a??o de enzimas biotransformadoras podem explicar tais resultados

Orientador: Pilar Rodriguez de Massaguer / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-05T11:41:03Z (GMT). No. of bitstreams: 1 Sanches_CristianaDePaulaPacheco_D.pdf: 39491118 bytes, checksum: 1b9b67b564e9684ca74114092ff37150 (MD5) Previous issue date: 2005 / Resumo: O resumo poderá ser visualizado no texto completo da tese digital / Abstract: The abstract is available with the full electronic document / Doutorado / Doutor em Ciência de Alimentos

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-07-03T15:08:24Z No. of bitstreams: 1 Dissertação - Marcos César Fernandes Pessoa.pdf: 6006738 bytes, checksum: 6bf14f8b1d3cb3d2908ac7e37e22c668 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-13T15:51:34Z (GMT) No. of bitstreams: 1 Dissertação - Marcos César Fernandes Pessoa.pdf: 6006738 bytes, checksum: 6bf14f8b1d3cb3d2908ac7e37e22c668 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-13T15:56:30Z (GMT) No. of bitstreams: 1 Dissertação - Marcos César Fernandes Pessoa.pdf: 6006738 bytes, checksum: 6bf14f8b1d3cb3d2908ac7e37e22c668 (MD5) / Made available in DSpace on 2015-07-13T15:56:30Z (GMT). No. of bitstreams: 1 Dissertação - Marcos César Fernandes Pessoa.pdf: 6006738 bytes, checksum: 6bf14f8b1d3cb3d2908ac7e37e22c668 (MD5) Previous issue date: 2009-07-15 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Bacillus thuringiensis is a Gram-positive bacterium commonly used in the tropical disease vectors and agriculture pragues control. Despite of its use both agriculture and human health, this bacterium can be enterotoxins producer that are also present in a few Bacillus cereus strains, emphasizing the non-haemolytic enterotoxin (NHE), haemolysin BL (HBL) and enterotoxin T (BceT) that have been related to food poisoning outbreaks reported in the literature. Thereby, this work had as a purpose to identify and to realize a genotypic characterization of these enterotoxins in one hundred B. thuringiensis strains isolated in the Amazon State, as well as to achieve the sequencing of these enterotoxin genes starting from the product of Polymerase Chain Reaction (PCR). The prevalence of these enterotoxin genes in B. thuringiensis strains by PCR method was relatively high, of which the results for the seven genes researched (bceT, hblA, hblD, hblC, nheA, nheB and nheC) showed different between themselves. By the genotypic profile were determined 27 groups and was evidenciated that 41% of the strains were positives for all the enterotoxin genes, whereas 3% were negatives for all the genes studied.. The analysis of the nucleotides and amino acids sequences of the Amazonian B. thuringiensis strains identified similarities with the nucleotides and amino acids sequences that are deposited in the GenBank and EMBL databases. / Bacillus thuringiensis é uma bactéria Gram-positiva comumente utilizada no controle de vetores de doenças tropicais e pragas da agricultura. Apesar de seu uso tanto na agricultura quanto em saúde humana, esta bactéria pode ser produtora de enterotoxinas que estão presentes também em algumas linhagens de Bacillus cereus, destacando-se a enterotoxina não-hemolítica (NHE), a hemolisina BL (HBL) e a enterotoxina T (BceT), que têm sido relacionadas a surtos de intoxicação alimentar relatados na literatura. Em vista disso, este trabalho teve como objetivo identificar e caracterizar genotipicamente estas enterotoxinas em 100 linhagens de B. thuringiensis isoladas no Estado do Amazonas, bem como realizar o seqüenciamento destes genes de enterotoxinas a partir do produto da Reação em Cadeia de Polimerase (PCR). A prevalência dos genes destas enterotoxinas nas estirpes de B. thuringiensis pelo método de PCR foi relativamente alta, cujos resultados para os sete genes pesquisados (bceT, hblA, hblD, hblC, nheA, nheB e nheC) mostraram-se distintos entre si. Pelo perfil genotípico foram determinados 27 grupos e ficou evidenciado que 41% das linhagens deram positivas para todos os genes de enterotoxinas, enquanto que 3% foram negativas para todos os genes estudados. A análise das sequências de nucleotídeos e de aminoácidos das linhagens de B. thuringiensis amazônicas identificou similaridades com as sequências de nucleotídeos e aminoácidos que estão depositadas no banco de dados do GenBank/EMBL.