Isolation of the Hg(II)‐volatilizing Bacillus sp. strain DC‐B2 and its potential to remediate Hg(II)‐contaminated soils

Abstract

BACKGROUND Mercury (Hg) contamination is a major global environmental problem, and its remediation using environmentally friendly biotechnologies has attracted increasing attention. In this study, an Hg(II)‐resistant bacterial strain, Bacillus sp. DC‐B2, was isolated from a metal‐contaminated site, and its ability to remediate five types of Hg‐contaminated soils was investigated. RESULTS The isolate DC‐B2 showed strong resistance to multiple metals and volatilized 91.6% of the Hg(II) in a culture with an initial Hg(II) concentration of 10 mg L−1 within 8 h. Microcosm experiments showed that the addition of DC‐B2 culture improved Hg(II) removal by 11.7–17.2% from four artificially Hg(II)‐spiked soil samples with initial Hg contents of approximately 100 mg kg−1 after incubating for 30 days under flooded conditions compared to the control treatment. For the field‐contaminated farmland soil containing 2.50 mg Hg kg−1, an Hg(II) elimination rate of 82.1% was achieved within 30 days with the DC‐B2 inoculation, relative to the 34.1% elimination rate observed for the uninoculated control. The amendment of peptone broth slightly inhibited Hg removal (2.2–8.7%). The remediation effectiveness was verified by observations of longer root and shoot lengths of lettuce plants grown in treated soils compared to those grown in the control soil. CONCLUSION The isolate Bacillus sp. DC‐B2 shows great potential to be developed as a bioagent for effective bioremediation of Hg‐contaminated soils. © 2018 Society of Chemical Industry

Risk of low stability Saccharomyces cerevisiae ATCC 9763-heavy metals complex in gastrointestinal simulated conditions

“…In this isotherm model, suppressing chemical interactions were detected between the adsorbing molecules. In contrast, the Freundlich model shows that biosorption process was heterogeneous, non-uniform, and multi-layer and was not ideal ( Chen et al., 2019 ). In the Freundlich isotherm model, chemical interactions were seen between the adsorbed molecules ( Raoov et al., 2013 ).…”

Investigation of the simulated microgravity impact on heavy metal biosorption by Saccharomyces cerevisiae

“…1 Pseudo-firstorder ln q e − q t = lnq e − K 1 t Al-Hazmi, (2010) Not fitted K 1 is rate constant, q e and q t adsorbed metals at equilibrium times (h), and at a given time (t) 2 Pseudosecondorder suppressing chemical interactions were seen between the adsorbed molecules (Raoov et al, 2013). Similar results about fitted and nonuniform biosorption process (Chen et al, 2019). In this model, chemical interactions were seen between the adsorbed molecules (Raoov et al, 2013).…”

“…The Langmuir model showed that the biosorption process was homogeneous, uniform, and monolayer, in which inhibitory chemical interactions were detected between the adsorbing molecules. Freundlich model biosorption process was heterogeneous, ununiform, multilayer, and not ideal (Chen et al., 2019 ), in which suppressing chemical interactions were seen between the adsorbed molecules (Raoov et al., 2013 ). Similar results about fitted Langmuir isotherm model were reported by Massoud et al.…”

“…The Langmuir model showed that the biosorption process was homogeneous, uniform, and monolayer, in which inhibitory chemical interactions were detected between the adsorbing molecules. Freundlich model biosorption process was heterogeneous, ununiform, multilayer, and not ideal (Chen et al, 2019), in which TA B L E 1 Kinetic model studies of Hg, Pb, Cd, and As adsorption by yeast: Linear regression analysis of pseudo-secondorder, as fitted model.…”

Functional Hyperbranched Polythioamides Synthesized from Catalyst‐free Multicomponent Polymerization of Elemental Sulfur†

“…Mercury pollution in water could cause serious environmental and health problems because of the toxicity of mercury species to respiratory and nerve systems, [ 57 ] the detection and removal of mercury ion are hence important and have been widely investigated with the mercury absorbents including biomaterials, [ 58 ] covalent organic frameworks, [ 59 ] traditional diatomite, [ 60 ] chitosan, [ 61 ] or modified activated carbon. [ 62 ] Linear or hyperbranched polymers with abundant thioamide moieties as well‐known ligands for Hg 2+ , could hence be developed as Hg 2+ absorbents, [ 30,38 ] and hb ‐P 1 , hb ‐P 5 and hb ‐P 6 were studied as examples.…”