RESUMEN
Epicoccum is a genus of ubiquitous fungi typically found in air, in soil, and on decaying vegetation. They also commonly display an endophytic lifestyle and are isolated from diverse plant tissues. The fungi from the genus Epicoccum are mainly known for their use as biocontrol agents against phytopathogens and for their ability to produce many secondary metabolites with potential biotechnological applications, such as antioxidant, anticancer,r and antimicrobial compounds. Among the bioactive compounds produced by Epicoccum spp., epicocconone is a commercially available fluorophore, D8646-2-6 is a patented telomerase inhibitor, and taxol is an anticancer drug originally isolated from Taxus brevifolia. Epicoccum spp. also produces epicolactone, an antimicrobial compound with a unique and complex structure that has aroused considerable interest in the chemical-synthesis community. The main goal of the present review is to discuss the diversity of secondary metabolites produced by Epicoccum spp., their biotechnological applications, and proposed hypothetical biosynthesis. In addition, the use of Epicoccum spp. as biocontrol agents and the pigments produced by these fungi are also discussed.
Asunto(s)
Ascomicetos/metabolismo , Biotecnología/métodos , Metabolismo Secundario , Animales , Antiinfecciosos/metabolismo , Antineoplásicos/metabolismo , Ascomicetos/química , Ascomicetos/genética , HumanosRESUMEN
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.
Asunto(s)
Animales , Plantas/microbiología , Ecología , Interacciones Huésped-Patógeno , Interacciones Microbianas , Microbiota , Microbiología del Suelo , Percepción de Quorum , Metabolismo SecundarioRESUMEN
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.
Asunto(s)
Interacciones Microbianas , Animales , Ecología , Interacciones Huésped-Patógeno , Humanos , Microbiota , Plantas/microbiología , Percepción de Quorum , Metabolismo Secundario , Microbiología del SueloRESUMEN
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.
RESUMEN
Transposable elements are ubiquitous and constitute an important source of genetic variation in addition to generating deleterious mutations. Several filamentous fungi are able to defend against transposable elements using RIP(repeat-induced point mutation)-like mechanisms, which induce mutations in duplicated sequences. The sequenced Colletotrichum graminicola genome and the availability of transposable element databases provide an efficient approach for identifying and characterizing transposable elements in this fungus, which was the subject of this study. We identified 132 full-sized Tc1-Mariner transposable elements in the sequenced C. graminicola genome, which were divided into six families. Several putative transposases that have been found in these elements have conserved DDE motifs, but all are interrupted by stop codons. An in silico analysis showed evidence for RIP-generated mutations. The TCg1 element, which was cloned from the Brazilian 2908 m isolate, has a putative transposase sequence with three characteristic conserved motifs. However, this sequence is interrupted by five stop codons. Genomic DNA from various isolates was analyzed by hybridization with an internal region of TCg1. All of the isolates featured transposable elements that were similar to TCg1, and several hybridization profiles were identified. C. graminicola has many Tc1-Mariner transposable elements that have been degenerated by characteristic RIP mutations. It is unlikely that any of the characterized elements are autonomous in the sequenced isolate. The possible existence of active copies in field isolates from Brazil was shown. The TCg1 element is present in several C. graminicola isolates and is a potentially useful molecular marker for population studies of this phytopathogen.
Asunto(s)
Colletotrichum/genética , Elementos Transponibles de ADN/genética , Genoma Fúngico/genética , Transposasas/genética , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Secuencia de Bases , Brasil , ADN de Hongos/química , ADN de Hongos/genética , Proteínas Fúngicas/genética , Marcadores Genéticos/genética , Variación Genética , Secuencias Invertidas Repetidas/genética , Datos de Secuencia Molecular , Mutación , Hibridación de Ácido Nucleico , Filogenia , Estructura Terciaria de Proteína , Alineación de Secuencia , Análisis de Secuencia de ADN , Transposasas/químicaRESUMEN
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.