2026-10-12T15:24:47Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33793243 2026-09-15T12:50:01Z category_26917 item_type_3 month_year_09_2026

<p dir="ltr"><b>A Calcium- and Magnesium-Tolerant Enterobacter sp. MTT Respiratory Inhibition Assay for Rapid Screening of Mercury and Silver in Industrial River Water</b></p> yunus shukor (10052324) Environmental biotechnology diagnostics (incl. biosensors) Whole-cell bioassay Enterobacter Mercury Silver Effect-based monitoring <p dir="ltr">Rapid biological screening can complement instrumental analysis by identifying water samples that warrant priority investigation. This study developed a whole-cell respiratory inhibition assay based on the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) by a locally isolated bacterium. Enterobacter sp. strain DRY13, retained respiratory activity in the presence of Ca2+ and Mg2+ yet responded strongly to toxic metals. supported tentative placement within Enterobacter. Among 13 metals tested, Ag+ and Hg2+ produced greater than 50% inhibition at 10 mg L−1. One-phase exponential models yielded IC50 values of 0.139 mg L−1 for Ag+ (95% CI, 0.115–0.173 mg L−1) and 0.144 mg L−1 for Hg2+ (95% CI, 0.106–0.221 mg L−1), with R2 values of 0.9842 and 0.999, respectively. The reported limits of detection were 0.0033 mg L−1 for Ag+ and 0.0216 mg L−1 for Hg2+; corresponding limits of quantification were 0.0294 and 0.0386 mg L−1. Most pesticides and solvent-related xenobiotics caused little inhibition at the tested concentrations, whereas sodium dodecyl sulfate was a notable interferent. River and industrial-estate samples inhibited MTT reduction, while tap water did not. Because ICP-AES measures total recoverable metal whereas whole-cell inhibition reflects the combined bioavailable toxic fraction, the assay is best interpreted as a rapid effect-based screen rather than a metal-specific quantitative method. The platform provides a simple basis for prioritizing contaminated samples for confirmatory instrumental analysis.</p> 2026-09-15T12:50:01Z Dataset Dataset 10.6084/m9.figshare.33793243.v1 https://figshare.com/articles/dataset/_p_dir_ltr_b_A_Calcium-_and_Magnesium-Tolerant_Enterobacter_sp_MTT_Respiratory_Inhibition_Assay_for_Rapid_Screening_of_Mercury_and_Silver_in_Industrial_River_Water_b_p_/33793243 CC BY 4.0