Biorremediación de mercurio y níquel por bacterias endófitas de macrófitas acuáticas

Bioremediation of mercury and nickel by endophytic bacteria of aquatic macrophytes

La contaminación ambiental se ha categorizado como uno de los principales problemas que afecta la salud de las diferentes formas de vida. Las bacterias endófitas (BE), son capaces de mejorar el estado nutricional de las plantas y remover contaminantes del suelo. La subregión la Mojana funciona como zona de amortización de ríos. En este estudio, se colectaron muestras de macrófitas acuáticas de las ciénagas de Ayapel, San Marcos y San Benito Abad, de los cuales se aislaron bacterias endófitas. Se cuantificó las densidades poblacional de estas bacterias y su respectiva tolerancia a los metales pesados níquel y mercurio. Posteriormente, las cepas tolerantes fueron identificadas molecularmente y se les evaluó su capacidad de promover el crecimiento vegetal. Un total de 182 morfotipos de bacterias endófitas fueron aislados, los mayores promedios de densidad poblacional se obtuvieron en las macrófitas de la ciénaga de San Benito Abad ubicada en las coordenadas coordenadas 8°55´32.81´´ N y 75°1´13.72” O. Los mayores promedios de morfotipos tolerantes a mercurio y níquel se encontraron en la ciénaga de Ayapel en las coordenadas 8°18´51.10´´ N y 75°8´8.26” O. Los resultados muestran que los aislados con mayor potencial biotecnológico son BAT6, BAR2 y PAT2, donde los dos primeros tienen una homología del 100%  con la especie Lysinibacillus fusifomis y el género Enterobacter, respectivamente, mientras que el tercer aislamiento tuvo una  homología del 96% con la especie Burkholderia cepacia. El presente estudio reporta por primera vez la presencia de Lysinibacillus fusifomis y Burkholderia cepacia asociadas a macrófitas en cuerpos cenagosos de Sucre y Córdoba.

Environmental pollution has been categorized as one of the main problems that affects the health of different life forms. Endophytic bacteria (BE) are able to improve the nutritional status of plants and remove soil contaminants. The Mojana subregion works as a river depreciation zone. In this study, samples of aquatic macrophytes were collected from the marshes of Ayapel, San Marcos and San Benito Abad, from which endophytic bacteria were isolated. The population densities of these bacteria and their respective tolerance to nickel and mercury heavy metals were quantified. Subsequently, the tolerant strains were molecularly identified and their ability to promote plant growth was evaluated, from which the population densities of endophytic bacteria and tolerance to heavy metals were isolated and determined. , to the tolerant isolates and capable of growing in nickel and mercury, plant growth promotion was evaluated, finally they were identified at the molecular level. A total of 182 morphotypes of endophytic bacteria were isolated, the highest population density averages were obtained in the macrophytes of the swamp of San Benito Abad located at the coordinates coordinates 8 ° 55´32.81´´ N and 75 ° 1´13.72 ”W , lo. The highest averages of mercury and nickel tolerant morphotypes were found in the Ayapel swamp at coordinates 8 ° 18´51.10´´ N and 75 ° 8´8.26 ”O. L The results show that the isolates with the greatest biotechnological potential are BAT6, BAR2 and PAT2, where the first two have a 100% homology with the species Lysinibacillus fusifomis and the genus Enterobacter, respectively, while the third isolation had a homology of 96% with the species Burkholderia cepacia show that the isolated BAT6, presented 100% homology with the species of bacteria Lysinibacillus fusifomis; BAR2 100% homology with the bacterial species belonging to the genus Enterobacter and PAT2 96% homology with the species Burkholderia cepacia. The present study reports for the first time the presence of Lysinibacillus fusifomis and Burkholderia cepacia associated with macrophytes in swampy bodies of Sucre and Córdoba.