Biosorption of lead (Pb2+) by the vegetative and decay cells and spores of Bacillus coagulans R11 isolated from lead mine soil. (November 2018)

• Record Type: Journal Article
• Authors: Xing, Si-Cheng; Chen, Jing-Yuan; Lv, Ning; Mi, Jian-Dui; Chen, Wei Li; Liang, Juan Boo; Liao, Xin-Di
• Is Part Of: Chemosphere. Volume 211(2018)
• Page Start: 804
• Page End: 816
• Publication Date: 2018-11
• Subjects: Bacillus coagulans -- Lead -- Vegetative cell -- Decay cell -- Spore -- Bioaccumulation; MRS De Man Rogosa Sharpe -- PBS Phosphate-buffered saline -- PVDF Polyvinylidene fluoride -- TE buffer Tris-EDTA buffer -- PCR Polymerase chain reaction -- ANOVA Analysis of variance -- SPSS Statistical Package for the Social Sciences -- TEM Transmission electronic microscopy -- FTIR Fourier transform infrared analyses; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2018.08.005
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The lead (Pb 2+ ) bioaccumulation capacities and mechanisms of three different physiological structures (vegetative cells, decay cells and spores) of B. coagulans R11 isolated from a lead mine were examined in this study. The results showed that the total Pb 2+ removal capacity of vegetative cells (17.53 mg/g) was at its optimal and higher than those of the spores and decay cells at the initial lead concentration of 50 mg/L. However, when the initial lead concentration surpassed 50 mg/L, Pb 2+ removal capacity of decay cells was more efficient. Zeta potential, Fourier transform infrared (FTIR) and functional group modification analyses demonstrated that the electrostatic attraction and chelating activity of the functional groups were the primary pathways involved in the extracellular accumulation of Pb 2+ by the vegetative cells and spores. However, the primary Pb 2+ binding pathway in the decay cells was hypothesized to be due to physical adsorption, which easily led to Pb 2+ desorption. Based on these results, we conclude that the vegetative cell is the ideal lead sorbent. Therefore, it is important to inhibit the transformation of the vegetative cells into decay cells and spores, which can be achieved by culturing the bacteria under anaerobic conditions to prevent spore formation. Heat stimulation can effectively enhance spore germination to generate vegetative cells. Highlights: Vegetative cell is the ideal morphological structure for Pb 2+ accumulation. Extracellular accumulation is the major Pb 2+ binding pathway for all tested structure. Pb ions desorption could occur easily for decay cell. The intracellular accumulation capacity of spore is very weak. Anaerobic and low temperature condition could prevent the formation of spore.