Bioremediation strategies for hexavalent chromium: Development and safety assessment of recombinant Escherichia coli strain 3458

Incidents of periodic water pollution and damage to aquatic organisms resulting from the mismanagement of hexavalent chromium emissions have been documented. Utilizing environmentally friendly bioremediation strategies has effectively controlled chromium pollution. The ChrA gene, responsible for hexavalent chromium remediation and sourced from Sporosarcina saromensis M52, was introduced into Escherichia coli to develop recombinant strain 3458. To improve scalability, response surface methodology was used to assess environmental factors influencing recombinant strain 3458's performance, alongside, a safety evaluation examining its impact on aquatic organisms and animals. The study revealed that recombinant strain 3458 possesses adsorption, reduction, and resistance capabilities, which facilitated the transformation of highly toxic hexavalent chromium into the less harmful trivalent form. Nevertheless, the strain may impact Chlorella sp., silt communities, and murine liver function through competitive inhibition and endotoxins produced by host cells. These findings offer a comprehensive approach to engineered microbial remediation and provide valuable insights into the safety and effectiveness of this biotechnological solution.