Utilizamos sobretudo o organismo modelo não patogénico Bacillus subtilis, para o qual existem ferramentas poderosas de análise genética. A nossa actividade centra-se no estudo dos mecanismos moleculares que controlam a metamorfose da célula bacteriana num esporo, incluindo a geração de assimetria e de informação posicional, a coordenação entre a expressão genética e o curso da morfogénese, e a montagem de estruturas supramoleculares. Representam assim um meio eficiente de preservação do genoma, actuando como verdadeiras cápsulas do tempo. Acima de tudo, os esporos bacterianos resistem ao tempo podendo permanecer viáveis durante muitos milhões de anos. Os esporos são estruturas celulares metabolicamente adormecidas, capazes de resistir a condições extremas, incluindo ambientes extraterrestres simulados ou reais, que resultariam na destruição rápida das células originais. doi:10.1371/journal.pgen.1005104įor further information visit the laboratory's websiteĮm condições nutricionais muito adversas, algumas bactérias iniciam um processo de diferenciação celular que resulta na produção de esporos. Henriques (2015) Dual-Specificity Anti-sigma Factor Reinforces Control of Cell-Type Specific Gene Expression in Bacillus subtilis. Mónica Serrano, JinXin Gao, João Bota, Ashley R.Henriques (2016) The SpoIIQ-SpoIIIAH complex of Clostridium difficile controls forespore engulfment and late stages of gene expression and spore morphogenesis. Henriques*, Isabelle Martin-Verstraete* (2016) A Recombination Directionality Factor Controls the Cell Type-Specific Activation of σK and the Fidelity of Spore Development in Clostridium difficile. Pereira, Laure Saujet, Pierre Boudry, Bruno Dupuy, Adriano O. Mónica Serrano, Nicolas Kint, Fátima C.difficile and we are elucidating the structure of the biofilm and the spatiotemporal control of its assembly. We have identified new genes involved in biofilm formation in C. Biofilms are a form of bacterial multicellular organization, which protects against harmful conditions in the host and creates nutrient-rich niches. We also study spore development in this organism, the structure and function of the spore surface layers and their role during infection as well as the regulatory links between spore formation and the production of virulence factors such as the toxins, flagella, or biofilms. Spores are essential for the dissemination of epidemic strains and for the environmental and host persistence of this intestinal pathogen. We use a combination of genetics, cell biology, biochemistry, structural and computational biology to study these processes.Ĭlostridium difficile is a strict anaerobe sporeforming organism and currently a major nosocomial pathogen. They also have to assemble multiprotein structures and organelles at specific cellular addresses and times during development. During spore differentiation, for instance, the two cells that participate in the process use cell-cell communication pathways and checkpoints to coordinate their programs of gene expression and to keep them in pace with the course of morphogenesis. We are interested in essential processes in bacterial cell biology and development such as how cells achieve and maintain proper cell shape, and how they differentiate into specialized cell types.
We study the developmental biology of Bacillus subtilis and related organisms. We are studying the molecular mechanisms that drive the sporulation process with model organisms, to also understand pathogenicity in dangerous strains, and to look for biotechnological and medical applications of spores. This review work provides a reference for spore control in food science and industry.Bacterial spores are encased in a protein coat that confers resistance against chemicals, lysis and predation, and is a key sensor of the environment. The CP sterilization mechanism and its application in spore inactivation were summarized. Therefore, the spore structure, formation, and germination were reviewed. But the CP inactivating effect and mechanism to spores still need more research and attention. As an emerging non-thermal sterilization technology, cold plasma (CP) has shown great potential in food sterilization. Heat sterilization is a simple and effective sterilization method, but it will destroy the quality and nutrition of food. However, different germination factors cause different germination effects, which in turn affect the inactivating results. “Sprout first and inactivate later” is the traditional idea of inactivating spores. However, due to their high resistance to stress, the inactivation of spores has been a pressing issue in the food industry. Bacterial spores, one of the main microorganisms, can cause food spoilage and food-borne diseases.