Role of S-layer proteins in the biosorption capacity of lead by <i>Lactobacillus kefir</i>

dc.creatorGerbino, Oscar Esteban
dc.creatorCarasi, Paula
dc.creatorAraujo Andrade, Cuauhtémoc
dc.creatorTymczyszyn, Emma Elizabeth
dc.creatorGómez-Zavaglia, Andrea
dc.date2015-04
dc.date2022-05-09T13:38:30Z
dc.date.accessioned2023-07-15T04:47:37Z
dc.date.available2023-07-15T04:47:37Z
dc.identifierhttp://sedici.unlp.edu.ar/handle/10915/135854
dc.identifierissn:1573-0972
dc.identifierissn:0959-3993
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/7470907
dc.descriptionThe role of S-layer proteins (SLP) on the Pb²⁺ sequestrant capacity by <i>Lactobacillus kefir</i> CIDCA 8348 and JCM 5818 was investigated. Cultures in the stationary phase were treated with proteinase K. A dot blot assay was carried out to assess the removal of SLP. Strains with and without SLP were exposed to 0–0.5 mM Pb(NO₃)₂. The maximum binding capacity (q<sub>max</sub>) and the affinity coefficient (b) were calculated using the Langmuir equation. The structural effect of Pb²⁺ on microorganisms with and without SLP was determined using Raman spectroscopy. The bacterial interaction with Pb²⁺ led to a broadening in the phosphate bands (1,300–1,200 cm⁻¹ region) and strong alterations on amide and carboxylate-related bands (νCOO⁻ as and νCOO⁻ s). Microorganisms without SLP removed higher percentages of Pb²⁺ and had higher q<sub>max</sub> than those bearing SLP. Isolated SLP had much lower q<sub>max</sub> and also removed lower percentages of Pb²⁺ than the corresponding whole microorganisms. The hydrofobicity of both strains dramatically dropped when removing SLP. When bearing SLP, strains do not expose a large amount of charged groups on their surfaces, thus making less efficient the Pb²⁺ removal. On the contrary, the extremely low hydrofobicity of microorganisms without SLP (and consequently, their higher capacity to remove Pb²⁺) can be explained on the basis of a greater exposure of charged chemical groups for the interaction with Pb²⁺. The viability of bacteria without SLP was not significantly lower than that of bacteria bearing SLP. However, microorganisms without SLP were more prone to the detrimental effect of Pb²⁺, thus suggesting that SLP acts as a protective rather than as a sequestrant layer.
dc.descriptionFacultad de Ciencias Exactas
dc.descriptionCentro de Investigación y Desarrollo en Criotecnología de Alimentos
dc.formatapplication/pdf
dc.format583-592
dc.languageen
dc.rightshttp://creativecommons.org/licenses/by/4.0/
dc.rightsCreative Commons Attribution 4.0 International (CC BY 4.0)
dc.subjectCiencias Exactas
dc.subjectBiología
dc.subjectS-layer proteins
dc.subjectLactobacillus kefir
dc.subjectBiosorption
dc.subjectLead
dc.titleRole of S-layer proteins in the biosorption capacity of lead by <i>Lactobacillus kefir</i>
dc.typeArticulo
dc.typeArticulo


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