AUTHOR=El-Sharkawy Reyad M. , Khairy Mohamed , Abbas Mohamed H. H. , Zaki Magdi E. A. , El-Hadary Abdalla E. 

TITLE=Innovative optimization for enhancing Pb2+ biosorption from aqueous solutions using Bacillus subtilis

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1384639

DOI=10.3389/fmicb.2024.1384639

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>Toxic heavy metal pollution has been considered a major ecosystem pollution source. Unceasing or rare performance of Pb<sup>2+</sup> to the surrounding environment causes damage to the kidney, nervous, and liver systems. Microbial remediation has acquired prominence in recent decades due to its high efficiency, environment-friendliness, and cost-effectiveness.</p></sec><sec><title>Methods</title><p>The lead biosorption by <italic>Bacillus subtilis</italic> was optimized by two successive paradigms, namely, a definitive screening design (DSD) and an artificial neural network (ANN), to maximize the sorption process.</p></sec><sec><title>Results</title><p>Five physicochemical variables showed a significant influence (<italic>p</italic> &lt; 0.05) on the Pb<sup>2+</sup> biosorption with optimal levels of pH 6.1, temperature 30°C, glucose 1.5%, yeast extract 1.7%, and MgSO<sub>4</sub>.7H<sub>2</sub>O 0.2, resulting in a 96.12% removal rate. The Pb<sup>2+</sup> biosorption mechanism using <italic>B. subtilis</italic> biomass was investigated by performing several analyses before and after Pb<sup>2+</sup> biosorption. The maximum Pb<sup>2+</sup> biosorption capacity of <italic>B. subtilis</italic> was 61.8 mg/g at a 0.3 g biosorbent dose, pH 6.0, temperature 30°C, and contact time 60 min. Langmuir’s isotherm and pseudo-second-order model with R<sup>2</sup> of 0.991 and 0.999 were suitable for the biosorption data, predicting a monolayer adsorption and chemisorption mechanism, respectively.</p></sec><sec><title>Discussion</title><p>The outcome of the present research seems to be a first attempt to apply intelligence paradigms in the optimization of low-cost Pb<sup>2+</sup> biosorption using <italic>B. subtilis</italic> biomass, justifying their promising application for enhancing the removal efficiency of heavy metal ions using biosorbents from contaminated aqueous systems.</p></sec>