en Environmental Health, Sciences, and Engineering Environmental Health, Sciences, and Engineering پژوهشي Original Article <div class="WordSection1" style="text-align: justify;"><span style="line-height:1;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="page:WordSection1"><b><span style="color:black">Background:</span></b><span style="color:black"> Bacterial tolerance to heavy metals, commonly expressed as minimum inhibitory concentration (MIC), is often evaluated alongside biosorption capacity. However, the extent to which MIC can reliably predict metal absorption has rarely been quantified. This study investigated the quantitative relationship between MIC and biosorption capacity in native bacterial strains isolated from industrially contaminated soils.</span><br> <b><span style="color:black">Methods: </span></b><span style="color:black">Twenty morphologically and biochemically distinct strains were isolated. MIC values for lead, zinc, cadmium, and a mixture of the three metals were determined using the broth microdilution method. Biosorption capacity was assessed through triplicate batch experiments, and the amount of metal absorbed by biomass was quantified using ICP-OES. A cell-free abiotic control confirmed that metal recovery without biomass remained below 0.5 ppm. The most efficient strains were identified by 16S rRNA gene sequencing. We analyzed the relationship between MIC and biosorption using Pearson correlation, one-way ANOVA, and regression analysis of log-transformed MIC values.</span><br> <b><span style="color:black">Results:</span></b><span style="color:black"> Biosorption capacity consistently increased with resistance level. All tested systems showed significant positive correlations: the multi-metal mixture (r = 0.895), lead (r = 0.879), cadmium (r = 0.780), and zinc (r = 0.748), all with <i>p</i> < 0.001. Strains with higher MIC values showed significantly greater biosorption. <i>Pseudomonas aeruginosa</i> and <i>Bacillus sp</i>. were the most efficient biosorbing strains.</span><br> <b><span style="color:black">Conclusion:</span></b><span style="color:black"> MIC can serve as a simple and cost-effective criterion for the preliminary selection of promising bacterial biosorbents for heavy-metal bioremediation.</span></span></span></span></span></div> <div aria-label="Page Break" class="cke_pagebreak" contenteditable="false" data-cke-display-name="pagebreak" data-cke-pagebreak="1" style="page-break-after:always" title="Page Break"></div> Heavy metals, Biosorption, Minimum inhibitory concentration, Metal resistance, Native bacteria, Bioremediation, 0 0 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-719-3&slc_lang=en&sid=1 Seyed Alireza Fathi seyedalireza.fathi@iau.ac.ir 100319475328460016823 0009-0008-5068-104x No Department of Environment, La.C. Islamic Azad University, Lahijan, Iran. Hasan Karimzadegan Drkarimzadegan@iau.ac.ir 100319475328460016824 100319475328460016824 Yes Department of Environment, La.C. Islamic Azad University, Lahijan, Iran. Fatemeh Shariati Feizabadi f.shariati@iau.ac.ir 100319475328460016825 100319475328460016825 No Department of Environment, La.C. Islamic Azad University, Lahijan, Iran. Leila Ooshaksaraie le.ooshaksaraei@iau.ac.ir 100319475328460016826 100319475328460016826 No Department of Environment, La.C. Islamic Azad University, Lahijan, Iran.