RESUMEN
Pesticides are chemicals used in agriculture, forestry, and, to some extent, public health. As effective as they can be, due to the limited biodegradability and toxicity of some of them, they can also have negative environmental and health impacts. Pesticide biodegradation is important because it can help mitigate the negative effects of pesticides. Many types of microorganisms, including bacteria, fungi, and algae, can degrade pesticides; microorganisms are able to bioremediate pesticides using diverse metabolic pathways where enzymatic degradation plays a crucial role in achieving chemical transformation of the pesticides. The growing concern about the environmental and health impacts of pesticides is pushing the industry of these products to develop more sustainable alternatives, such as high biodegradable chemicals. The degradative properties of microorganisms could be fully exploited using the advances in genetic engineering and biotechnology, paving the way for more effective bioremediation strategies, new technologies, and novel applications. The purpose of the current review is to discuss the microorganisms that have demonstrated their capacity to degrade pesticides and those categorized by the World Health Organization as important for the impact they may have on human health. A comprehensive list of microorganisms is presented, and some metabolic pathways and enzymes for pesticide degradation and the genetics behind this process are discussed. Due to the high number of microorganisms known to be capable of degrading pesticides and the low number of metabolic pathways that are fully described for this purpose, more research must be conducted in this field, and more enzymes and genes are yet to be discovered with the possibility of finding more efficient metabolic pathways for pesticide biodegradation.
Asunto(s)
Plaguicidas , Humanos , Plaguicidas/toxicidad , Biodegradación Ambiental , Bacterias/metabolismo , Hongos/metabolismo , AgriculturaRESUMEN
Material pomáceo fue mezclado en distintas proporciones a sustratos de arena, con el objetivo de medir la capacidad de retención de humedad de las mezclas y evaluar el uso de piedra pómez de desechos industriales en la elaboración de sustratos con arena. Cuatro diferentes porcentajes, en base a volumen, de piedra pómez (10, 20, 30 y 40%) se adicionaron a sustratos de arena. En la primera parte del experimento se evaluó el comportamiento de la humedad a través del tiempo; en la segunda parte se determinó la frecuencia de reposición de agua a los sustratos que tuvieron una mayor capacidad de retención de humedad. Los resultados muestran que el contenido de humedad aumenta debido al incremento de porosidad producida por las partículas de pómez. El mayor contenido de humedad (43,75%), después de agregar agua, se obtuvo en la mezcla con el 30% de pómez. La piedra pómez de desecho industrial puede ser utilizada en la elaboración de sustratos para incrementar la retención de humedad con bajo costo y fácil obtención.
Pumice material was mixed in different proportions to sand substrates with the purpose of measuring the water retention capacity of the mixtures and of evaluating the use of industrial pumice residues in the production of substrates with sand. Four different mixtures of pumice residues and sand (10, 20, 30 and 40%) were prepared in order to measure, in a first stage, moisture content through time; in a second stage, the frequency of moisture replenishing was determined for the substrate mixtures that showed a higher water retention capacity. The results show that moisture content increased with the amount of pumice added to the sand, due to the porosity increase produced by pumice particles. The greater moisture content (43.75%) after irrigation was accomplished with the mixture with 30% of pumice material. Pumice residues from industrial process can be used in substrate production to increase water retention at low cost and with an easy availability.
Material de púmice estava misturado em taxas diferentes lixar substrato com o propósito medir a capacidade de retenção de água dessas misturas e avaliar o uso de resíduos de púmice de indústria na produção de substrato com areia. Quatro porcentagem fundada mistura de resíduos de púmice e areia (10, 20, 30 e 40%) estava preparado para medir em um primeiro conteúdo de umidade de fase por tempo; e em uma segunda fase a freqüência de umidade que enche às misturas de substrato com capacidade de retenção de água mais alta. Os resultados mostrados aquele conteúdo de umidade aumentado com a quantia de púmice acrescentada à areia, devido ao incremento de porosidade produzido por partículas de púmice. O maior conteúdo de umidade (43,75%) depois que irrigação fosse realizada com a mistura com 30% de material de púmice. Podem ser usados resíduos de púmice de processo industrial em produção de substrato para aumentar retenção de água a baixo custo e disponibilidade de facilidade.