Removal of Pb(II) by Pellicle-Like Biofilm-Producing Methylobacterium hispanicum EM2 Strain from Aqueous Media

Abstract

As concerns are increasing about drinking water contamination with heavy metals, we investigated the possible use of a pellicle (floating biofilm)-like biofilm-producing microorganism as a biosorbent for the treatment of Pb(II) in aqueous solutions. The bacterial pellicle-producing Methylobacterium hispanicum EM2 strain (EM2) was newly isolated from mine tailing soil, and we investigated its use as a biosorbent for treating a Pb(II)-contaminated aqueous solution. The EM2 strain was strongly resistant to Pb(II) up to a concentration of 800 mg/L, and achieved remarkable adsorption performance (adsorption rate and maximum adsorption capacity of 96% ± 3.2% and 79.84 mg/g, respectively) under optimal conditions (pH, biomass content, contact time, and initial Pb(II) concentration of 7.1 g/L, 60 min, and 10 mg/L, respectively). The adsorption of Pb(II) was characterized by scanning electron microscopy-energy dispersive x-ray spectroscopy and Fourier-transform infrared analysis. The equilibrium data matched the Freundlich isotherm model well, indicating the occurrence of multilayer adsorption of Pb(II) onto the heterogeneous surface of the EM2 strain, which was also consistent with the pseudo-second-order kinetic model (R2 = 0.98). The high Pb(II) removal efficiency was also confirmed by conducting an adsorption experiment using Pb(II)-contaminated industrial wastewater.

The Leaf Microbiome of Tobacco Plants across Eight Chinese Provinces

“…Ochrobactrum lupini from Qujing was known to degrade pesticides (chlorothalonil and cypermethrin) [50,51]. The other three species identified in the LEfSe have no previously reported functional associations, but their genera do contain species capable of degrading PAHs and heavy metals detoxication [64][65][66][67][68][69]. For instance, Enterobacter sp.…”

Potential application of thermophilic bacterium Aeribacillus pallidus MRP280 for lead removal from aqueous solution

“…BDL2 [20]. In other cases, a lower uptake capacity was observed in Bacillus AS2 Pb which had a capacity of 74.5 mg/g (99.5 % of initial Pb) [30], Methylobacterium hispanicum EM2 showed Pb removal of 96 % and uptake capacity at 79.84 mg/g [31]. These different results may be attributed to differences in the experimental condition i.e.…”

The Synthesis of PbS NPs and Biosorption of Pb(II) by Shinella Zoogloeoides PQ7 in Aqueous Conditions

“…From the table and figures, the correlation coefficient (R 2 ) of the Freundlich model (0.986) is better than that of the Langmuir model (0.978). This might be because the process of absorbing lead ions by PQ7 was based on adsorption on different surfaces and because the adsorption sites were not identical to or independent of each other, as reported in previous studies [21][22][23]. Table 2 compares the biosorption of Pb(II) by different bacteria.…”

“…One milliliter seed culture of PQ7 (OD 600 = 1) was inoculated into 100 mL LB medium at 30 • C with 200 rpm shaking speed until the stationary phase was reached. The cells were collected by centrifugation at 10,000 rpm for 15 min and washed three times with deionized water [21]. Then, the samples were used for biosorption experiments.…”