Resumo Neste trabalho avaliou-se a biorremediação da água com conteúdos de cloretos utilizando microalgas nativas (MCA) fornecidas pelo Centro de Estudos e Pesquisas em Biotecnologia (CIBIOT) da Universidad Pontifícia Bolivariana. As microalgas empregadas apresentaram uma adaptação ao meio de cultura e as condições operacionais avaliadas atingindo uma produção de CO2 em mg L-1 de 53,0, 26,6, 56,0, 16,0 e 30,0 e eficiências de remoção de cloretos de 16,37, 26,03, 40,04, 25,96 e 20,25% para MCA1, MCA2, MCA3, MCA4 e MCA5 respectivamente. A biorremediação da água com conteúdos de cloretos foi realizada em modo batelada alimentada (Feed Batch) com uma concentração inicial de cloretos de 20585 mg L-1. A alimentação foi realizada a cada 2 dias. A variável manipulada foi: ensaio um, uma vazão de MCA3 (10% de inoculo); ensaio dois, uma vazão de NPK e ensaio três, uma vazão de MCA3+0,5 g L-1 NPK. As eficiências de remoção foram 66,88%, 63,41% e 66,98% para os ensaios um, dois e três, respectivamente num tempo do bioprocesso total de 55 dias.

Abstract In this work it was carried out the bioremediation of water containing chlorides with native microalgae (MCA) provided by the Centre for study and research in biotechnology (CIBIOT) at Universidad Pontificia Bolivariana. Microalgae presented an adaptation to the water and so the conditions evaluated reaching a production of CO2 in mg L-1 of 53.0, 26.6, 56.0, 16.0 and 30.0 and chloride removal efficiencies of 16.37, 26.03, 40.04, 25.96 and 20.25% for microalgae1, microalgae2, microalgae3, microalgae4 and microalgae5 respectively. Water bioremediation process was carried out with content of chlorides in fed batch system with an initial concentration of chlorides of 20585 mg L-1 every 2 days. The Manipulated variables were: the flow of MCA3 (10% inoculum) for test one; NPK flow for test two, and flow of flow of MCA3+0.5 g L-1 NPK. Chloride removal efficiencies were 66.88%, 63.41% and 66.98% for test one, two and three respectively, for a total bioprocess time of 55 days.

Resumen Se evaluó las relaciones hídricas y el intercambio de gases en Theobroma cacao var. Guasare bajo períodos de déficit hídrico. Se midieron las variables microclimáticas (temperatura del aire, humedad relativa y radiación fotosintéticamente activa), intercambio de gases (conductancia estomática, tasas de transpiración y de asimilación de CO2) y potencial hídrico foliar, a lo largo del día en plantas sujetas a 3, 12 y 25 días sin agua. Se utilizaron curvas presión-volumen para determinar el potencial osmótico en el punto de pérdida de turgor. Se observó una disminución significativa (P<0,05) en la conductancia estomática a medida que aumentó el estrés hídrico. Las características del intercambio de gases también se vieron afectadas. Se registró un evidente ajuste osmótico en las plantas sometidas a 3 y 12 días sin agua, mientras que no ocurrió un ajuste adicional 25 días después. La eficiencia en el uso del agua aumentó a medida que la disponibilidad hídrica disminuyó. Las tasas de asimilación de CO2 se redujeron en un 25% en las plantas severamente estresadas, mientras que las tasas de transpiración disminuyeron en un 39%, indicando que el cierre estomático afecta las pérdidas de agua en un mayor grado.

Water relations and gas exchange of Theobroma cacao var. Guasare under periods of water deficit were evaluated. Microclimatic characteristics (air temperature, relative humidity and photosynthetically active radiation), leaf gas exchange (stomatal conductance, transpiration and CO2 assimilation rates) and leaf water potential were measured throughout the day in plants subjected to 3, 12 and 25 days without water. Pressure-volume curves were used to determine osmotic potential at turgor loss. A significant decrease in stomatal conductance was observed as water stress increased. As a consequence, gas exchange characteristics were also affected. An evident osmotic adjustment was recorded in plants subjected to 3 and 12 days without water, while no additional adjustment occurred 25 days later. Water use efficiency increased as water availability decreased. CO2 assimilation rates decreased 25% in severely stressed plants, while water loss was reduced in 39% indicating that stomatal closure affects water loss to a greater degree.