Microcalorimetric studies of interaction between extracellular polymeric substance and sulfide minerals

Zhu, Jianyu; Yang, Peng; Li, Bang-mei; Zhang, Jingxia; Huang, Qiuxia

doi:10.1016/s1003-6326(09)60022-4

Cited by 8 publications

(1 citation statement)

References 15 publications

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“…In soil, bacterial exudates may participate in many ecologically relevant processes. For example, EPS can sorb or flocculate other OM constituents (Esparza-Soto and Westerhoff, 2003;Ding et al, 2008), bind toxic metals (Guibaud et al, 2006;Kumar et al, 2007;Aguilera et al, 2008;Kiran and Kaushik, 2008), promote the dissolution of minerals (Zhu et al, 2008), and enhance aggregate stability (Watanabe et al, 1999;Jaisi et al, 2007). Moreover, as EPS comprise intrinsically labile compounds, they provide a readily available C source for biosynthesis (de Brouwer et al, 2002) although an unknown portion may escape microbial utilization via sorption to mineral surfaces or complexation with metals.…”

Section: Introductionmentioning

confidence: 99%

Stabilization of extracellular polymeric substances (Bacillus subtilis) by adsorption to and coprecipitation with Al forms

Mikutta

Zang

Chorover

et al. 2011

Geochimica et Cosmochimica Acta

108

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Stabilization of extracellular polymeric substances (Bacillus subtilis) by adsorption to and coprecipitation with Al forms Mikutta, R.; Zang, U.; Chorover, J.; Haumaier, L.; Kalbitz, K. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract Extracellular polymeric substances (EPS) are continuously produced by bacteria during their growth and metabolism. In soils, EPS are bound to cell surfaces, associated with biofilms, or released into solution where they can react with other solutes and soil particle surfaces. If such reaction results in a decrease in EPS bioaccessibility, it may contribute to stabilization of microbial-derived organic carbon (OC) in soil. Here we examined: (i) the chemical fractionation of EPS produced by a common Gram positive soil bacterial strain (Bacillus subtilis) during reaction with dissolved and colloidal Al species and (ii) the resulting stabilization against desorption and microbial decay by the respective coprecipitation (with dissolved Al) and adsorption (with Al(OH) 3(am) ) processes. Coprecipitates and adsorption complexes obtained following EPS-Al reaction as a function of pH and ionic strength were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stability of adsorbed and coprecipitated EPS against biodegradation was assessed by mineralization experiments for 1100 h. Up to 60% of the initial 100 mg/L EPS-C was adsorbed at the highest initial molar Al:C ratio (1.86), but this still resulted only in a moderate OC mass fraction in the solid phase (17 mg/g Al(OH) 3(am) ). In contrast, while coprecipitation by Al was less efficient in removing EPS from solution (maximum values of 33% at molar Al:C ratios of 0.1-0.2), the OC mass fraction in the solid product was substantially larger than that in adsorption complexes. Organic P compounds were preferentially bound during both adsorption and coprecipitation. Data are consistent with strong ligand exchange of EPS phosphoryl groups during adsorption to Al(OH) 3(am) , whereas for coprecipitation weaker sorption mechanisms are also involved. X-ray photoelectron analyses indicate an intimate mixing of EPS with Al in the coprecipitates, which is not observed in the case of EPS adsorption complexes. The incubation experiments...

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