| Congresso Brasileiro de Microbiologia 2023 | Resumo: 592-1 | ||||
Resumo:Human activities and modern industrialization have increased emissions of heavy metals into the environment. Heavy metal pollution represents a major threat to ecosystems and can be lethal to humans. These elements when deposited in the arable soil layer become available in solution and readily available to plants, becoming a source of contamination for the entire trophic chain. Bioremediation processes use living organisms and their enzymes in the biodegradation of toxic compounds, aiming at their eradication, reduction, or transformation into less toxic substances. Bacillus subtilis (Gram-positive bacterium) is listed in the literature as a highly efficient bacterium in the removal of heavy metals. This species can withstand and adapt to several variations in environmental conditions, such as large variations in pH and temperature. The objective of this study was to evaluate the capacity of B. subtilis to bioaccumulate cadmium in water samples. For this reason, B. subtilis was growth on TSB100 (100% of standard concentration), and TSB33 (diluted at 33% of the standard concentration) to compare with the B. subtilis growth in water and TSB33 containing the metal, cadmium. The cadmium initial solutions were prepared at 100 ppm. The solutions were placed in agitation on 150 rpm at 35 °C, and samples were taken from 1h to 144h. The samples were analyzed by bacteria growth by Sterifil Filtration System with 0.22 μm membranes and metal biocumulation by X-ray fluorescence, ICP/MS. The B. subtilis growth results showed a maximum cell mass concentration, for TSB100, around 3 g/L in 72 hours and for TSB33 around 0.7 g/L in 96 hours. Nevertheless, when it was analyzed the B. subtilis growth in water with Cd the cell biomass was around 6.9 g/L in 3 hours; and the maximum Cd removal occurred in 120 and 144 hours with efficiency of 91% and 92.3%, around biomass concentration in 16 g/L. The system with Bacillus bacteria can be efficient to bioaccumulating heavy metals from aqueous solutions and can be employed as a cost- effective treatment for the bioremediation of industrial effluents and areas contaminated with heavy metals. Palavras-chave: Bioremediation, Bacillus subtilis, Cadmium, Heavy metal | |||||