Bioremediation of hexavalent chromium in vitro with an autochthonous microbial consortium of Enterobacter hormaechei and Bacillus subtilis., immobilized in biobeads of sodium alginate and polyvinyl alcohol for the treatment of contaminated water

Authors:Jorge Andres Cuellar Gil, Nelsy Loango Chamorro, Fabiana Maria Lora Suarez, Edwin David Morales Alvarez, Marcela Orjuela Rodriguez, Eliana Marcela Soto Rueda and Patricia Landazuri. Description: The contamination of CrVI by various companies worldwide is one of the major concerns of environmental protection agencies, as water bodies are increasingly polluted by different industrial processes such as galvanization, alloying, tanning, and textile dyeing. Therefore, CrVI is considered a highly toxic element due to its high water solubility, high oxidation state, and ability to permeate biological membranes. This causes issues in the gastrointestinal, central and peripheral nervous, hematological, and renal systems, with the emergence of carcinogenic tissues. In this context, efficient, environmentally friendly, and cost-effective strategies for CrVI reduction in water are lacking.Thus, this research proposed a novel bioremediation strategy involving two microorganisms: Enterobacter hormaechei and Bacillus subtilis. These microorganisms, isolated from tanneries in the Department of Quindio, demonstrated resistance and reduction activity against CrVI in preliminary tests. Initially, both microorganisms were immobilized together using sodium alginate and polyvinyl alcohol beads and subjected to an in vitro fluidized bead bioreactor with synthetic wastewater containing 100 ppm of CrVI. The treated water from the bioreactor was used in two in vivo models guppy fish Poecilia reticulata and tomato seeds Solanum lycopersicum L. to evaluate its toxicity. Finally, the genomes of these two microorganisms were analyzed to identify and study potential genes involved in the expression of CrVI resistance and reduction using bioinformatics tools.