dc.creator | Gerbino, Oscar Esteban | |
dc.creator | Carasi, Paula | |
dc.creator | Araujo Andrade, Cuauhtémoc | |
dc.creator | Tymczyszyn, Emma Elizabeth | |
dc.creator | Gómez-Zavaglia, Andrea | |
dc.date | 2015-04 | |
dc.date | 2022-05-09T13:38:30Z | |
dc.date.accessioned | 2023-07-15T04:47:37Z | |
dc.date.available | 2023-07-15T04:47:37Z | |
dc.identifier | http://sedici.unlp.edu.ar/handle/10915/135854 | |
dc.identifier | issn:1573-0972 | |
dc.identifier | issn:0959-3993 | |
dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/7470907 | |
dc.description | The 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.description | Facultad de Ciencias Exactas | |
dc.description | Centro de Investigación y Desarrollo en Criotecnología de Alimentos | |
dc.format | application/pdf | |
dc.format | 583-592 | |
dc.language | en | |
dc.rights | http://creativecommons.org/licenses/by/4.0/ | |
dc.rights | Creative Commons Attribution 4.0 International (CC BY 4.0) | |
dc.subject | Ciencias Exactas | |
dc.subject | Biología | |
dc.subject | S-layer proteins | |
dc.subject | Lactobacillus kefir | |
dc.subject | Biosorption | |
dc.subject | Lead | |
dc.title | Role of S-layer proteins in the biosorption capacity of lead by <i>Lactobacillus kefir</i> | |
dc.type | Articulo | |
dc.type | Articulo | |