SPECIATION OF SELENIUM IN Pleurotus ostreatus AND Lentinula edodes MUSHROOMS

L.S. ASSUNÇÃO¹, M.C.S. SILVA², M.G. FERNANDEZ³, T. GARCÍA-BARRERA⁴, J.L. GOMÉZ-ARIZA⁵, J. BAUTISTA⁶, M.C.M. KASUYA⁷*
¹Departament of Microbiology, Universidade Federal de Viçosa, Viçosa, 36570-000, Minas Gerais, Brazil.
²Departament of Microbiology, Universidade Federal de Viçosa, Viçosa, 36570-000, Minas Gerais, Brazil.
³Department of Chemistry and Material Sciences, University of Huelva, Huelva, 21007, Andalusia, Spain.
⁴Department of Chemistry and Material Sciences, University of Huelva, Huelva, 21007, Andalusia, Spain.
⁵Department of Chemistry and Material Sciences, University of Huelva, Huelva, 21007, Andalusia, Spain.
⁶Department of Biochemistry and Molecular Biology, University of Sevilla, Sevilla, 41012, Andalusia Spain.
⁷Department of Biochemistry and Molecular Biology, University of Sevilla, Sevilla, 41012, Andalusia Spain.
* Corresponding Author : mkasuya@ufv.br

Received : 18-07-2014     Accepted : 12-08-2014     Published : 09-12-2014
Volume : 5     Issue : 1       Pages : 79 - 86
J Biotechnol Lett 5.1 (2014):79-86

Keywords : Protein extract, selenomethionine, solubilization buffer, HPLC, ICP-MS, selenium-containing proteins
Academic Editor : Janos Vetter
Conflict of Interest : The authors declare that there are no conflicts of interest.
Acknowledgements/Funding : The authors are very grateful to the Brazilian Financial Agencies CNPq, Capes and Fapemig, and also to the Ministry of Science and Innovation of the Government of Spain.

Pleurotus ostreatus and Lentinula edodes are two of the most commercialized mushrooms species in the world and exhibit the potential to accumulate selenium (Se). The form of Se in the protein extracts of P. ostreatus and L. edodes mushrooms enriched with Se has been investigated with the aim of obtaining a protein extract with high concentrations of selenomethionine (SeMet). For an approach to the speciation of Se incorporated in P. ostreatus proteins, size exclusion high performance liquid chromatography was used in combination with inductively coupled plasma mass spectrometry (SEC-HPLC-ICP-MS) and two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Se-enriched mushrooms of P. ostreatus and L. edodes were used. The proteins were extracted with phosphate buffer, borate buffer and solubilization buffer (2DE) and were purified by acetone precipitation. The extracts were analyzed by reversed phase high performance liquid chromatography in combination with inductively coupled plasma mass spectrometry (RP-HPLC-ICP-MS). The efficiency of the extraction of Se compounds varied according to the buffer type and the species of fungus. The 2DE buffer was the most efficient, reaching a recovery of 60% and 30% of all Se in the protein extracts of to P. ostreatus and L. edodes, respectively. The main form of Se in the protein extracts was SeMet. The Se concentration was higher in P. ostreatus than in L. edodes. The P. ostreatus protein extracts with 2DE buffer represent a great potential for obtaining biomass proteins with high SeMet concentrations on an industrial scale. The 2D-PAGE analyses revealed the presence of eight Se-containing proteins. The nutritional value of protein biomass containing SeMet presently has a high potential to be explored by pharmaceutical industries.