Constructing hybrid microorganism-material systems to improve pollutant bioremediation: Investigating the improved bioactivity and quorum sensing of a functional strain with acid-added microwave hydrochar

Abstract

The ecology is seriously endangered by atrazine residue, which is generated and accumulated by agricultural practices. The atrazine-degrading bacterium Paenarthrobacter sp. KN0901 and acid-added microwave hydrochar are used in this work to construct hybrid microorganism-material systems that effectively remove atrazine from the environment. The baseline atrazine degradation rate increased by 25.5 % when H₂SO₄-added microwave hydrochar (ISHC) was added, after 72 h of incubation at 15 °C. With the addition of acid-added microwave hydrochar, the number and autoinducer-2 activity of strain KN0901 increased significantly, suggesting the enhanced quorum sensing compared to the free bacterial cells. The biochemical reaction levels in strain KN0901 were regulated as a result of enhanced quorum sensing. The expression levels of genes associated with atrazine biodegradation in strain KN0901 were significantly elevated following the addition of AMHC, leading to an increased production of hydrolases involved in atrazine degradation. Furthermore, the biofilm formation process was improved with AMHC treatment, facilitating a greater exchange of substances between the interior and exterior of the bacterial cells. This enhancement allows for more efficient uptake of atrazine by strain KN0901, thereby promoting the degradation. The findings indicate that acid-added microwave hydrochars improved atrazine degradation by enhancing the quorum sensing of strain KN0901. The atrazine degradation rate in this system increased under different conditions, including changes in the pH, temperature, salt concentration, and heavy metal concentrations. This study presents a novel methodology for the development and application of bioremediation techniques aimed at addressing atrazine contamination in various environmental conditions.