ABSTRACT
ABSTRACT The microorganism-microorganism or microorganism-host interactions are the key strategy to colonize and establish in a variety of different environments. These interactions involve all ecological aspects, including physiochemical changes, metabolite exchange, metabolite conversion, signaling, chemotaxis and genetic exchange resulting in genotype selection. In addition, the establishment in the environment depends on the species diversity, since high functional redundancy in the microbial community increases the competitive ability of the community, decreasing the possibility of an invader to establish in this environment. Therefore, these associations are the result of a co-evolution process that leads to the adaptation and specialization, allowing the occupation of different niches, by reducing biotic and abiotic stress or exchanging growth factors and signaling. Microbial interactions occur by the transference of molecular and genetic information, and many mechanisms can be involved in this exchange, such as secondary metabolites, siderophores, quorum sensing system, biofilm formation, and cellular transduction signaling, among others. The ultimate unit of interaction is the gene expression of each organism in response to an environmental (biotic or abiotic) stimulus, which is responsible for the production of molecules involved in these interactions. Therefore, in the present review, we focused on some molecular mechanisms involved in the microbial interaction, not only in microbial-host interaction, which has been exploited by other reviews, but also in the molecular strategy used by different microorganisms in the environment that can modulate the establishment and structuration of the microbial community.
Subject(s)
Animals , Plants/microbiology , Ecology , Host-Pathogen Interactions , Microbial Interactions , Microbiota , Soil Microbiology , Quorum Sensing , Secondary MetabolismABSTRACT
ABSTRACT The microorganism-microorganism or microorganism-host interactions are the key strategy to colonize and establish in a variety of different environments. These interactions involve all ecological aspects, including physiochemical changes, metabolite exchange, metabolite conversion, signaling, chemotaxis and genetic exchange resulting in genotype selection. In addition, the establishment in the environment depends on the species diversity, since high functional redundancy in the microbial community increases the competitive ability of the community, decreasing the possibility of an invader to establish in this environment. Therefore, these associations are the result of a co-evolution process that leads to the adaptation and specialization, allowing the occupation of different niches, by reducing biotic and abiotic stress or exchanging growth factors and signaling. Microbial interactions occur by the transference of molecular and genetic information, and many mechanisms can be involved in this exchange, such as secondary metabolites, siderophores, quorum sensing system, biofilm formation, and cellular transduction signaling, among others. The ultimate unit of interaction is the gene expression of each organism in response to an environmental (biotic or abiotic) stimulus, which is responsible for the production of molecules involved in these interactions. Therefore, in the present review, we focused on some molecular mechanisms involved in the microbial interaction, not only in microbial-host interaction, which has been exploited by other reviews, but also in the molecular strategy used by different microorganisms in the environment that can modulate the establishment and structuration of the microbial community.
ABSTRACT
A qualidade dos produtos alimentícios e a sua influência sobre a nutrição e a saúde humana vêm merecendo lugar de destaque nos meios científicos. Essa preocupação se deve ao grande número de produtos alimentícios existentes e a uma tendência atual de se ingerir produtos naturais. Com o objetivo de verificar as condições higiênico-sanitárias de produtos naturais, foram analisadas seis amostras de linhaça, produto com crescente consumo por suas várias propriedades e benefícios a saúde. Foram avaliadas todas as marcas comerciais de linhaça em grãos e farinha disponíveis no mercado local na cidade de Fortaleza (CE), em relação à contagem total de bactérias aeróbias mesófilas pela técnica do Spread Plate. Metade das amostras analisadas apresentou contaminação por fungos, com contagens que variaram de 6,5 x 103UFC/g a 1,3 x 105UFC/g, enquanto 50% das amostras apresentaram contagens inferiores a 3 x 10 UFC/g e/ou até mesmo ausência de contaminação fúngica. Com relação às contagens de bactérias aeróbias mesófilas, 67% dos produtos analisados apresentaram valores variando de 1,04 x 104 UFC/g a 1,49 x 105 UFC/g. Estes resultados apontam a necessidade de uma avaliação das condições higiênico-sanitárias, uma vez que a presença destes grupos de micro-organismos sugere condições inadequadas de processamento, manipulação e armazenamento.