<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Han, Xi</style></author><author><style face="normal" font="default" size="100%">Yidan Hu</style></author><author><style face="normal" font="default" size="100%">Yanbo Yue</style></author><author><style face="normal" font="default" size="100%">Yuefei Ding</style></author><author><style face="normal" font="default" size="100%">Bin Cao</style></author><author><style face="normal" font="default" size="100%">Shi, Liang</style></author><author><style face="normal" font="default" size="100%">Juan Liu</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biofilm engineering through c-di-GMP tuning boosts bioleaching efficiency and arsenic tolerance in &lt;em&gt;Acidithiobacillus ferrooxidans&lt;/em&gt;</style></title><secondary-title><style face="normal" font="default" size="100%">Applied and environmental microbiology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2026</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://journals.asm.org/doi/full/10.1128/aem.02288-25</style></url></web-urls></urls><pages><style face="normal" font="default" size="100%">17</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Bioleaching offers a sustainable alternative to conventional metallurgy, but its application is limited by low leaching rates, inhibition by heavy metals, and prolonged adaptation. Here, we engineered &lt;em&gt;Acidithiobacillus ferrooxidans&lt;/em&gt;, a model bioleaching microorganism ubiquitous in mining environments, by modulating intracellular bis(3′ −5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) signaling to enhance biofilm formation, bioleaching efficiency, and arsenic tolerance. Overexpression of diguanylate cyclase genes &lt;em&gt;AFE_1379&lt;/em&gt;, &lt;em&gt;AFE_0053&lt;/em&gt;, and&lt;em&gt; AFE_1373&lt;/em&gt; produced engineered strains S-222, S-306, and S-651, respectively, with 1.7-, 2.5-, and 5-fold higher intracellular c-di-GMP levels than the control carrying the empty plasmid vector. Under arsenic-free condi tions, all engineered strains showed similar growth profiles, but S-306, at intermediate c-di-GMP (306.3 ± 28.1 μg mg−1), formed cytochrome-rich biofilms with low internal resistance and achieved the highest bioleaching efficiency. Under arsenic stress, S-651, at high c-di-GMP (651.4 ± 15.5 μg mg−1), developed polysaccharide-rich biofilms that enhanced arsenic tolerance, scorodite (FeAsO₄·2H₂O) precipitation, and bioleaching performance. Transcriptomic analysis confirmed these strain-specific gene expression patterns. These findings demonstrate that tuning intracellular c-di-GMP enables &lt;em&gt;A. ferrooxidans&lt;/em&gt; to reprogram biofilm matrix composition for extracellular electron uptake and heavy-metal resistance, providing a synthetic biology strategy for environmentally friendly bioleaching and tailings recycling</style></abstract></record></records></xml>