The Food and Drug Administration has recently expressed concern for the safety of seafood and seafood products. One of the concerns is the presence of Bacillus cereus in fresh blue crab meat. Bacillus cereus is a spore-forming pathogen whose spores survive the customary thermal treatments applied during cooking and pasteurization; therefore it could potentially present a health concern to consumers as the microorganism could increase to pathogenic levels. The objectives of this study were to evaluate the effects of a post-processing method i.e. high hydrostatic pressure treatment on the quality of fresh crab meat and to evaluate the effectiveness of high pressures on the inactivation of B. cereus spores. Fresh blue crab meat was pressurized at 300 and 550 MPa at 25° C for 5 min and stored at 4° C for 31 days to determine the pressurization effects on the microbiological, physical, and sensory quality of the meat. A pressure of 300 MPa caused a 1 log reduction in total aerobic plate count and a 3 day lag period, whereas 550 MPa inactivated 2 logs in total aerobic plate count with no evident lag phase. Physical and sensory qualities of pressurized crab meat were not statistically different from the untreated crab meat (P>0.05). A pressure of 300 MPa extended the shelf-life from 17 to over 24 days with the prevalence of Carnobacterium piscicola at the time of spoilage. Crab meat treated with 550 MPa was not rejected by sensory panels at day 31 and Enterococcus spp. was identified as the predominant microorganism. High hydrostatic pressure (550 MPa at 40° C for 15 min) inactivated less than 1 log (0.66 log) of B. cereus spores inoculated in fresh crab meat. The meat essentially had a protective effect on pressure inactivation of the spores. During storage (31 days), surviving B. cereus was suppressed and outgrown by the other pressure resistant microflora at a storage temperature of 12° C. At 4° C, B. cereus could compete with the other pressure-resistant microflora and was isolated even at the end of the storage period (day 31); however, diarrheal toxin was not detected in any stored samples. / Ph. D.

No description available.

Made available in DSpace on 2015-03-26T13:52:03Z (GMT). No. of bitstreams: 1 texto completo.pdf: 406557 bytes, checksum: f8e8d62d3ae14f56df99a0e2bc645da0 (MD5) Previous issue date: 2006-04-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bacteriocins from lactic acid bacteria have been suggested as an alternative to traditional food preservation methods, such as heat treatment, that interfere with natural characteristics of the food. Nisin is the bacteriocin that has been most used in foods. Recently, a new bacteriocin, bovicin HC5, produced by Streptococcus bovis HC5, was characterized. Previous work indicated that this bacteriocin has activity against Listeria monocytogenes and Clostridium sporogenes. In this study, the activity of this bacteriocin was tested against Bacillus cereus, Bacillus thuringiensis and Clostridium tyrobutyricum isolated form spoiled mango pulp. The addition of bovicin HC5 (40 to 160 AU/mL) into BHI media resulted in reduced specific growth rate and maximal optical densities of B. cereus, B. thuringiensis and C. tyrobutyricum. Concentrations of 40 and 80 AU/mL increased lag phase duration for at least 10 h. When 160 AU/mL was used, growth was not observed even after 144 h. The effect of bovicin HC5 against vegetative cells inoculated into mango pulp was bactericidal and more pronounced at acidic conditions. After 24 h of incubation with the bacteriocin, the viable cell number was bellow the detection level. Similar results were obtained when nisin was used. When C. tyrobutyricum was inoculated into mango pulp with 100 AU/mL of bovicin HC5, gas production was not observed for at least 10 days of incubation. Bovicin HC5 reduced spore germination of B. cereus and B. thuringiensis inoculated into mango pulp, and the number of non-germinated spores after 122 h of incubation was at least 100-fold greater than control treatments. Bovicin HC5 did not affect the thermal resistance of B. cereus and B. thuringiensis spores. However, if added to the mango pulp, bovicin HC5 could remain stable during the heat treatment, and reduce spore germination of these microorganisms. Cultures of B. cereus, B. thuringiensis and C. tyrobutyricum that were transferred successively in the presence of subletal doses of bovicin HC5 did not become resistant. Considering the results obtained in this study and the fact that bovicin HC5 was stable in culture supernatants and in mango pulp, it seems that this bacteriocin could be useful to prevent the spoilage of mango pulp by B. cereus, B. thuringiensis and C. tyrobutyricum. / Bacteriocinas de bactérias do ácido láctico têm sido propostas como alternativa aos métodos tradicionais de conservação de alimentos, como tratamento térmico, que interferem nas características naturais do alimento. A nisina é a bacteriocina que tem sido mais utilizada em alimentos. Recentemente, uma nova bacteriocina, bovicina HC5 produzida por Streptococcus bovis HC5, foi caracterizada e apresentou efetividade contra Listeria monocytogenes e Clostridium sporogenes. Neste estudo, a atividade desta bacteriocina foi testada contra Bacillus cereus, Bacillus thuringiensis e linhagens de Clostridium tyrobutyricum isolados da polpa de manga deteriorada. A adição de 40 a 160 UA/mL de bovicina HC5 em caldo BHI resultou na diminuição da velocidade específica de crescimento e da DO máxima atingida por B. cereus, B. thuringiensis e C. tyrobutyricum. Concentrações de 40 e 80 UA/mL de bovicina HC5 resultaram no aumento da fase lag dos isolados em pelo menos 10 h e quando a concentração utilizada foi de 160 UA/mL, o crescimento não foi observado por, pelo menos, 144 h. Concentração de 100 UA/mL de bovicina HC5 foi bactericida para células vegetativas inoculadas em polpa de manga e este efeito foi mais pronunciado em condições acídicas. Após 24 horas de incubação na presença da bacteriocina, o número de células viáveis das bactérias avaliadas ficou abaixo do limite de detecção. Resultados semelhantes foram obtidos com a nisina. Quando as linhagens de C. tyrobutyricum foram inoculadas em polpa de manga contendo 100 UA/mL de bovicina HC5, a produção de gás não foi observada por até 10 dias de incubação. Bovicina HC5 reduziu a germinação de esporos de B. cereus e B. thuringiensis e o número de esporos no estado dormente após 122 h de incubação foi, pelo menos, 100 vezes maior do que o observado no tratamento controle, sem bacteriocina. Esta bacteriocina não teve efeito na resistência térmica de esporos de B. cereus e B. thuringiensis. Entretanto, uma vez que a bovicina HC5 apresenta resistência a altas temperaturas (121 ºC/20 min), ela pode permanecer estável na polpa de manga após o tratamento térmico e reduzir a germinação dos esporos sobreviventes. A transferência dos isolados por, aproximadamente, 40 gerações na presença de 20 UA/mL de bovicina HC5 não causou adaptação dos microrganismos deterioradores. Esta bacteriocina permaneceu estável após incubação em mistura com o sobrenadante das culturas e com a polpa de manga. Considerando os resultados obtidos neste trabalho, a bovicina HC5 parece ser útil para reduzir a deterioração de polpa de manga causada por B. cereus, B. thuringiensis e C. tyrobutyricum.

Master of Science / Food Science Institute- Animal Sciences and Industry / Kelly J. K. Getty / The Food and Drug Administration’s Bacteriological Analytical Manual recommends two enumeration methods for Bacillus spp.: 1) standard plating method using mannitol-egg yolk-polymyxin (MYP) agar and 2) most probable number (MPN) method with tryptic soy broth supplemented with 0.1% polymyxin sulfate. Preliminary research evaluated three inoculum preparation methods using EZ-Spore™ B. cereus pellets. Two methods involved EZ-Spore™ B. cereus pellets that were dissolved in deionized (DI) water, grown in brain heart infusion broth with manganese sulfate, and then heated to produce spores. The third inoculum preparation method of dissolving EZ-Spore™ pellets only in DI water was the most efficient due to 100% spores being present in the inoculum. Preliminary research also determined that MPN method recovered greater (p<0.05) B. cereus populations than MYP method in inoculated ultra-high temperature pasteurized skim and 2% milk. The objective of the main study was to compare the MYP and MPN method for detection and enumeration of B. cereus in raw and high-temperature-short-time pasteurized skim, 2%, and whole milk at 4 °C for 96 h. Milk samples were inoculated with B. cereus EZ-Spores™ dissolved in DI water and sampled at 0, 48, and 96 h after inoculation. No differences (p>0.05) were observed among sampling times so data was pooled for overall mean values for each treatment. The overall B. cereus population mean of pooled sampling times for MPN method (2.59 log CFU/mL) was greater (p<0.05) than MYP plating method (1.89 log CFU/mL). B. cereus populations ranged from 3.40 log CFU/mL to 2.40 log CFU/mL for inoculated milk treatments for MYP and MPN methods, which is well below the necessary level for toxin production. Even though MPN method enumerated more B. cereus, the MYP method should be used by industry for enumeration of B. cereus due to its ease of use and rapid turnover time (2 d compared to 5 d with MPN). However, MPN method should be used for validation research due to its greater populations recovered. EZ-Spore™ B. cereus pellets were found to be an acceptable spore inoculum for validation research because the inoculum consists of 100% spores and does not contain vegetative cells.

Bacillus cereus est une bactérie très largement disséminée dans l'environnement. Certaines souches sont à l'origine de toxi-infections alimentaires de type émétique ou diarrhéique. Afin de coloniser l'intestin et induire un syndrome diarrhéique, B. cereus doit s'adapter aux variations d'oxygénation et de potentiel d'oxydoréduction rencontrées, se multiplier et sécréter des toxines. En comparant les capacités métaboliques et les capacités de sécrétion de l'entérotoxine Nhe de quatre souches de B. cereus, nous avons mis en évidence que la L-lactate déshydrogénase A (LdhA) était quelles que soient les conditions de croissance impliquée à la fois dans le métabolisme fermentaire et dans la toxinogénèse de B. cereus. LdhA contribue au maintien du ratio NAD+/NADH intracellulaire et son absence affecte les capacités d'expression de plusieurs gènes d'entérotoxines en anaérobiose et en aérobiose chez la souche F4430/73. Afin de déterminer si l'effet observé sur les toxines était indirect et dépendant du régulateur rédox Rex, un mutant ne synthétisant plus Rex a été construit. La caractérisation de ce mutant a mis en évidence le rôle de Rex dans le métabolisme de B. cereus, dans la réponse au stress oxydant et dans la toxinogénèse. De part sa structure et sa capacité a lié l'ADN, Rex pourrait être un facteur de transcription contrôlant l'expression des gènes codant les entérotoxines. Sa capacité de fixation sur l'ADN est dépendante du ratio NAD+/NADH. Afin de déterminer si LdhA pouvait réguler directement l'expression des gènes des toxines, ldhA a été exprimé chez E. coli et purifiée sous la forme d'une protéine fusion. Les premières expériences de retard sur gel n'ont pas permis de mettre en évidence de fixation sur les régions promotrices de toxines

Bacillus cereus est fréquemment associé à des toxi-infections alimentaires et peut être responsable de pathologies opportunistes sévères. Les facteurs d'adaptations de B. cereus chez l'hôte, liés à son pouvoir pathogène, sont encore inconnus. La capacité d'acquérir le fer lors d'une infection, est une importante réponse adaptative des bactéries, leur permettant de surmonter le manque de fer imposé par l'hôte. Nos travaux ont permis l'identification de nouveaux facteurs impliqués dans l'adaptation de B. cereus chez l'hôte, ainsi que la caractérisation d'une nouvelle protéine IlsA (Iron regulated leucine-rich surface protein) fortement exprimée in vivo. L'identification de ces facteurs a été réalisée à l'aide du système IVET (In Vivo Expression Technology), adapté à la souche B. cereus ATCC 14579 et analysé après infection chez la larve du lépidoptère Galleria mellonella. Ce système permet la détection des promoteurs activés de façon transitoire. L'analyse de la structure protéique d'IlsA, montre quatre domaines conservés: un peptide signal d'export N-terminal, un domaine NEAT potentiellement impliqué dans le transport du fer, suivi d'une région riche en leucine (LRR) susceptible d'interagir avec les protéines de l'hôte, et un domaine SLH de liaison à la surface bactérienne. La présence d'une boîte fur dans la région promotrice d'ilsA suggère une régulation dépendante du fer. Les analyses transcriptionnelles ont montré qu'ilsA est en effet, exprimé dans les conditions de carence en fer in vitro et in vivo. De plus, nous avons démontré qu'IlsA est localisée à la surface et qu'elle est nécessaire pour l'acquisition de fer à partir des protéines présentes chez l'hôte : l'hémoglobine, l'hème et la ferritine, et ceci en se liant directement avec elles. En outre, l'étude de la séquence protéique du domaine NEAT d'IlsA, suggère qu'il serait responsable de l'interaction avec l'hème. Par ailleurs, nous avons montré que l'inactivation d'ilsA affecte la survie et la virulence de B. cereus chez l'insecte, et chez les macrophages murins. Nos résultats indiquent qu'IlsA est un facteur d'adaptation essentiel pour l'acquisition de fer au cours de l'infection, contribuant à la pathogénie de B. cereus chez les invertébrés et vertébrés.

Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 164-183.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2017-04-27T14:23:05Z No. of bitstreams: 1 texto completo.pdf: 166311 bytes, checksum: 83322a34768e7a94f65989a1722e7533 (MD5) / Made available in DSpace on 2017-04-27T14:23:05Z (GMT). No. of bitstreams: 1 texto completo.pdf: 166311 bytes, checksum: 83322a34768e7a94f65989a1722e7533 (MD5) Previous issue date: 2004-08-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Três procariotas obtidos de filoplano de tomateiro (Bacillus cereus, Pseudomonas putida, Novosphingobium capsulatum), previamente selecionados como bons antagonistas de patógenos da cultura foram formulados em cinco formas distintas e avaliados quanto a sua efetividade como agentes de biocontrole. Quatro das cinco formulações, consistiam de produtos comerciais (Agromil-Raiz, Agromil-S, Ecolife 40 and ISR 2000) os quais propágulos dos antagonistas foram incorporados. A quinta formulação foi proposta no presente trabalho e consiste de uma solução de nutrientes com estratos de parede de células de Saccharomyces cerevisiae e goma xantana. Os efeitos deletérios das formulações sobre o crescimento dos antagonistas bem como a sobrevivência foram investigados. Os resultados indicam que Agromil-S e ISR 2000 tem efeito inibitório sobre o crescimento dos antagonistas os outros produtos não interferem significantemente na multiplicação dos antagonistas. A vida de prateleira dos antagonistas na formulação proposta foi estudada e nenhuma foi eficiente em aumentar a sobrevivência quando comparadas com o controle. O biocontrole experimental de doenças do tomateiro induzidas por três patógenos Corynespora cassiicola, Pseudomonas syringae pv. tomato, e oidio respectivamente, em casa de vegetação foi tentado para todos aos antagonistas e para todas as formulações, o controle foi alcançado embora em alguns casos não se encontrou diferença significativa entre o tratamento e o controle. Mais esforços e pesquisas devem ser realizados afim de melhorar a proteção de células a serem dispensadas em plantas. / To improve each antagonist efficiency as control agent of tomato leaf diseases, a study was carried out on five distinct formulae consisting of additives and one out of three autochthonous, isolated prokaryotic residents (Bacillus cereus, Pseudomonas putida, Novosphingobium capsulatum) of the tomato phylloplane and already selected as good antagonists to tomato pathogens. Four of these five formulations consisted of commercial products (Agromil-Raiz, Agromil-S, Ecolife 40 and ISR 2000) to which each antagonist living propagules were incorporated. The fifth of these combinations consisted of a nutrient solution amended with a Saccharomyces cerevisiae cell wall extract along with xanthan gum. Therefore, under consideration were the effects of each formula on each antagonist protective action and survival. Results of in vitro studies indicated that Agromil-S and ISR 2000 inhibited the antagonists' growth while the others didn't interfere in a significant way with the antagonists’ multiplication. In shelf live experiments, none of the studied formulation was efficient enough to increase significantly the antagonist survival when compared to controls. Under greenhouse conditions, every antagonist, in all formulas, controlled the tomato leaf diseases caused by Corynespora cassiicola, Pseudomonas syringae pv. tomato, or Oidium sp., although differences between some treatments and controls were not significant. We feel that with this we have only begun our efforts to find ways to improve protection of the antagonist’s living cells being delivered to tomato plants, and which will render them eventually well protected against leaf pathogens. . / Dissertação importada do Alexandria

This master thesis is oriented on study antimicrobial effects extracts and macerates from cure Stevia rebaudiana Bertoni. Teoretical part describes basic information about plant Stevia, summary of health significant matters contained in Stevia and posobilities preparing extracts from Stevia. Antimicrobial effects extracts and macerates from cure Stevia were testing on food-borne bacteria (Bacillus cereus and Micrococcus luteus) and yeasts (Geotrichum candidum and Hansenula anomala). Microorganism, extracts and macerates were chosen on basis previous study (Study of antimicrobial effects Stevia Rebaudiana extracts, Eva Rakovská). For screening antimicrobial activity were determined the growth curves by using turbidimetrie for bacteria and direct treetment metod of cells number for yeasts. Antimicrobial effects were confirmed aplication with diffusion pit method on the agar ranges. From the results flow the testing extracts and macerates from stevia analysed antimicrobial effects. The best effect was demostrated on macerates and the most sensitive was bacteria Micrococcus luteus with the best inhibitoring effects.

Depuis la vulgarisation de certains concepts comme la globalisation ou la mondialisation, le secteur agroalimentaire a connu une expansion fulgurante et un engouement incessant pour la commercialisation d’aliments entre les peuples à travers le monde. Ce phénomène, contribuant significativement à l’accroissement économique des marchés, n’est toutefois pas sans risque. Pendant ce temps, les dangers de sources microbiologiques, notamment les pathogènes, sont véhiculés par des matrices alimentaires et voyagent d’un pays à l’autre, ce qui augmente le risque de contamination pour les consommateurs. Conséquemment, on assiste à une augmentation des cas d’allergies alimentaires, d’intoxications ou de toxi-infections alimentaires dont les agents étiologiques peuvent venir des quatre coins du monde. À cet effet, les organismes réglementaires comme l’Agence canadienne d’inspection des aliments (ACIA), Santé Canada, la Food and Drug Administration (USFDA) américaine ou d’autres autorités internationales compétentes comme l’Organisation des Nations unies pour l’alimentation et l’agriculture(FAO) et l’Organisation mondiale de la santé (OMS) multiplient leurs efforts afin de mettre en place des normes et politiques réglementaires pour aider l’industrie agroalimentaire à renforcer les contrôles depuis la fabrication jusqu’à la commercialisation des aliments. Les dangers microbiologiques venant de pathogènes comme Bacillus cereus demeurent un risque de santé publique majeur qu’il faut maîtriser afin d’assurer la protection des consommateurs. Bien que de nombreuses techniques de contrôle (e.g., additifs alimentaires, haute pression hydrostatique, rayonnements ionisants, procédés thermiques, etc.) ont été développées et utilisées pour assurer la salubrité et l’innocuité des aliments, dans certains cas cela n’a pas permis de produire des aliments totalement exempts de bactéries responsables de la dégradation/altération des aliments et de pathogènes causant des intoxications alimentaires comme c’est le cas avec B. cereus. En effet, cette bactérie pathogène est ubiquitaire, aérobie et anaérobie facultative. Elle est capable de produire dans une grande variété d’aliments et d’ingrédients comme les épices des spores très résistantes ainsi que différents types de toxines pouvant causer la diarrhée, la nausée, le vomissement et même la mort. Dans cette optique, et vue la grande difficulté à maitriser la contamination des aliments causée par ce pathogène, l’objectif général de cette recherche a été d’utiliser la technologie d’électro-activation, une branche appliquée de l’électrochimie qui s’intéresse notamment à la réactivité des solutions aqueuses, comme méthode alternative et potentiellement efficace pour lutter contre B. cereus afin de produire des aliments plus sécuritaires avec une grande valeur nutritionnelle et organoleptique. Pour y parvenir, des solutions aqueuses de sels d’acides organiques de lactate de calcium, d’ascorbate de calcium et de leur mélange équimolaire ont été électro-activées dans un réacteur soumis à un courant électrique continu avec des intensités de l’ordre de 250, 500 et 750 mA pendant un maximum de temps de 30 minutes afin de produire les acides organiques conjugués respectifs; de l’acide lactique et de l’acide ascorbique. Dans la première partie de ce travail de recherche, les caractéristiques physicochimiques (e.g., pH, acidité titrable, pKa) des solutions électro-activées (SÉA) ont été étudiées et leurs profils moléculaires comparés à ceux d’acides standards respectifs en utilisant différentes techniques (e.g., FTIR, HPLC, DSC, DPPH), ce qui a permis de confirmer la production d’acides organiques conjugués respectifs des sels utilisés. Ces SÉA avaient un pH très bas, une acidité titrable élevée, notamment pour l’ascorbate de calcium et le mélange. En plus, une activité antioxydante élevée a été observée pour la solution électro-activée d’ascorbate de calcium et du mélange. Dans la deuxième partie de l’étude, les SÉA traitées à 250, 500 et 750 mA pendant 10, 20 et 30 min ont été retenues pour être mises en contact avec des cellules végétatives de Bacillus cereus ATCC 14579 en conditions modèles (contact direct) afin d’évaluer leurs effets antimicrobiens sur ce pathogène. Les cellules ont été testées en contact direct avec les SÉA pendant 5, 30 et 60 secondes. Le même traitement a été également réalisé par contact direct avec des acides organiques standards (lactique, ascorbique) pendant 5, 30, 60, et 120 secondes afin de faire des comparaisons. Les SÉA et les acides organiques standards correspondants avaient les mêmes valeurs d’acidité titrable. Par la suite, les cellules ont été observées au microscope (coloration au bleu de méthylène et fluorescence) afin d’évaluer les effets inhibiteurs/destructeurs de ces solutions. Également, les SÉA ont été diluées avec de l’eau distillée pour obtenir des solutions possédant 10 à 90% de l’acidité titrable (force) initiale pour être ensuite testées contre les cellules de B. cereus. Les résultats ont démontré que toutes les SÉA avaient une grande efficacité contre les cellules végétatives de B. cereus. Également, même à des taux de dilution représentant en moyenne 20% de la force initiale des SÉA, l’effet antimicrobien était très élevé pour les différentes solutions. L’observation de B. cereus au microscope a permis de confirmer les effets létaux des SÉA. Dans ce volet avec des cellules végétatives de B. cereus, l’efficacité des SÉA a été estimée à une réduction de 4–7 log UFC/mL. En plus, il a été démontré que le pouvoir antibactérien des SÉA était nettement plus élevé que celui des acides lactiques et ascorbiques standards (conventionnels). Dans la troisième partie de cette étude, des solutions électro-activées de lactate de calcium, d’ascorbate de calcium et de leur mélange équimolaire à 750 mA pendant 30 minutes ont été retenues et utilisées contre des spores de Bacillus cereus ATCC 14579 en conditions modèles et dans du saumon Atlantique frais. Les spores traitées ont été analysées à l’aide de microscopes électroniques à balayage et à transmission pour évaluer les effets sporicides des SÉA. Les résultats obtenus ont clairement montré un grand pouvoir sporicide des SÉA utilisées sur les spores de B. cereus avec une réduction de 7 à 9 log en utilisant une population initiale de spores de 10⁹ UFC/mL, dépendamment des conditions évaluées; à savoir : en contact direct (2–30 min), dans du saumon utilisé comme matrice alimentaire(2–7 min), ainsi qu’en combinaison avec de la chaleur modérée de 60, 70, 80 et 90 °C pendant 0.5–2 min. Également, il a été observé que la capacité sporicide des SÉA augmentait avec la température et le temps de contact. La microscopie électronique à balayage et à transmission a permis de constater que les SÉA pouvaient provoquer la destruction totale des cellules de B. cereus, et notamment la perforation de la membrane (cortex et manteau), ainsi que le reflux de différentes composantes de la structure des spores de B. cereus. Tenant compte des résultats obtenus dans cette étude, nous pouvons conclure que les solutions électro-activées à base de lactate de calcium, ascorbate de calcium et leur mélange, notamment celles électro-activées à 750 mA–30 min, pourraient être d’une grande contribution afin de renforcer la capacité de l’industrie alimentaire à lutter contre B. cereus ATCC 14579 et de produire des aliments plus sécuritaires pour le consommateur. / Since the popularization of concepts like globalization, the agri-food sector has experienced a huge expansion and a ceaseless craze for the marketing of food between the peoples worldwide. This phenomenon, contributing significantly to the economic growth of the markets, is not without risk, however. Meanwhile, microbiological hazards, including pathogens, are carried through food matrices and travel from one country to another, increasing the risk of contamination for consumers. Consequently, we are also witnessing an increase in cases of food allergies, foodborne illnesses and outbreaks, with etiological agents coming from all over the world. Thus, regulatory organisms such as Canadian Food Inspection Agency (CFIA), Health Canada, United States Food and Drug Administration (USFDA) or competent international authorities like Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO) are stepping up efforts to put in place regulatory standards and policies in order to help the food industry to strengthen controls from the processing to the marketing of foods. Microbiological hazards from pathogens like Bacillus cereus remain a major public health risk that must be controlled in order to ensure consumers protection. Although many techniques of control (e.g., food additives, high hydrostatic pressure, ionizing radiation, thermal processes, etc.) have been developed and used to ensure the safety and security of foods, in some instance this has not allowed to produce food products that are completely free of bacteria responsible for degradation/spoilage of food and pathogens causing food poisoning as is the case with B. cereus. Indeed, this pathogenic bacterium is ubiquitous, aerobic and facultative anaerobic. It is able to produce, in a wide variety of foods and ingredients such as spices, highly resistant spores as well as different types of toxins that can cause diarrhea, nausea, vomiting, and even death. In this context, and given the great difficulty in controlling the contamination of food caused by this pathogen, the general objective of this research was to use the electro-activation technology, an applied branch of electrochemistry which is particularly interested in the reactivity of aqueous solutions, as an alternative and potentially effective method to fight against B. cereus in order to produce safer foods with high nutritional and organoleptic values. To achieve this, aqueous solutions of organic acid salts of calcium lactate, calcium ascorbate and their equimolar mixture were electroactivated in a reactor subjected to a direct electric current with intensities of 250, 500 and 750 mA for a maximum time of 30 minutes in a bid to produce the respective conjugated organic acids, lactic acid and ascorbic acid. In the first part of this research work, the physicochemical characteristics (e.g.,pH, titratable acidity, pKa) of the electro-activated solutions (EAS) were studied and their molecular profiles compared to those of respective standard acids using different techniques (e.g., FTIR, HPLC, DSC, DPPH), which helped to confirm the production of conjugated organic acids from the respective salts used. These EAS had a very low pH, a high titratable acidity, particularly for the calcium ascorbate and the mixture. In addition, a high antioxidant activity was observed for the electro-activated calcium ascorbate solution and the mixture. In the second part of the study, the EAS treated at 250, 500 and 750 mA for 10,20 and 30 min were selected to be brought into contact with vegetative cells of Bacilluscereus ATCC 14579 under model conditions (direct contact) in order to evaluate their antimicrobial effects on this pathogen. The cells were tested in direct contact with the EAS for 5, 30 and 60 seconds. The same treatment was also carried out by direct contact with standard organic acids (lactic, ascorbic) for 5, 30, 60, and 120 seconds in order to make comparisons. The EAS and the corresponding standard organic acids had the same titratable acidity values. There after, the cells were observed under microscope (Methylene blue and fluorescence) to evaluate the inhibitory / destructive effects of these solutions. Also, the EAS were diluted with distilled water to obtain solutions with 10 to 90% of the initial titratable acidity (strength) to be tested against B. cereus cells. The results demonstrated that all the EAS made were highly effective against the vegetative cells of B.cereus. Also, even at dilution rates averaging 20% of the EAS initial strength, the antimicrobial effect was very high for the different solutions. In addition, the microscopic observation of B. cereus has confirmed the lethal effects of EAS. In this part with the vegetative B. cereus cells, the efficacy of the EAS was estimated to a reduction of 4–7 log CFU/mL. In addition, the antibacterial power of the EAS has been shown to be significantly higher than that of the standard (conventional) lactic and ascorbic acids. In the third part of the study, electro-activated solutions of calcium lactate, calcium ascorbate and their equimolar mixture at 750 mA for 30 min were selected and used against the spores of Bacillus cereus ATCC 14579 under model conditions and in fresh Atlantic salmon. The treated spores were analyzed using scanning and transmission electron microscopes to evaluate the sporicidal effects of EAS. The results obtained clearly showed a great sporicidal power of the EAS used on B. cereus spores with a reduction of 7 to 9 log using an initial spore population of 10⁹ CFU/mL, depending on the conditions assessed; namely: in direct contact (2–30 min), in salmon used as a food matrix (2–7 min), as well as in combination with moderate heat of 60, 70, 80 and 90 ℃ for 0.5–2 min. Also, it was observed that the sporicidal capacity of the EAS increased with temperature and contact time. Scanning and transmission electron microscopy showed that the EAS could cause the total destruction of B. cereus cells, including perforation of the membranes (cortex and coat), as well as the reflux of different components of the structure of B. cereus spores. Taking into account the results obtained in this study, we can conclude that the electro-activated solutions made with calcium lactate, calcium ascorbate and their mixture, especially those electro-activated at 750 mA–30 min, could be of a great contribution to reinforce the capacity of the food industry to control B. cereus ATCC 14579 and produces safer foods for the consumer.