Extracción de proteínas de s. Cerevisiae asistida por pulsos eléctricos de alto voltaje (pef): Efecto de la intensidad de tratamiento

• Autores: Juan Pedro Marín Sánchez, A. Berzosa, Inmaculada Álvarez Cano, J. Raso, A.C. Sánchez Gimeno
• Localización: XXIII Congreso Nacional de Microbiología de los Alimentos: Cartagena, 9-12 de septiembre de 2024 / coord. por Pablo Salvador Fernández Escámez, Alfredo Palop Gómez, Arturo Esnoz Nicuesa, Silvia Guillén Morer, 2024, ISBN 978-84-17853-94-5, págs. 150-153
• Idioma: español
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• Resumen

  • Yeasts may represent an alternative valuable novel protein source. Electroporation of microbial cells by Pulsed Electric Fields (PEF) has emerged as an effective technique for improving proteinextraction. Application of PEF for this purpose requires understanding how the treatment may affect events related to protein extraction such as the pore size or the release of proteases from yeast vacuoles. After electroporation of the biomass of a S. cerevisiae brewing strain by PEF treatments of different intensities (15 kV/cm, 43.3 to 207.0 kJ/kg), cells were incubated at 25°C,for monitoring over time the extraction of proteins, and amino acids, and the proteolytic enzyme activity.After 1 hour of extraction, 15% of total content of proteins were extracted independently of the intensity of the PEF treatment. However, by increasing extraction time until 72 hours, extractionof proteins and amino acids was more efficient in the yeast biomass treated in the range of total specific energiesfrom 43.4 kJ/kg to 121.1 kJ/kg. Extraction yieldsfor the most intense treatments applied (164.1 and 207 kJ/kg) decreased by 27 and 54%, respectively. For the different PEF treatments applied, a positive correlation was observed between protein extraction and proteolytic activity. This suggests that more intense PEF treatments caused protease inactivation, impairing the protein hydrolysis required for releasing the cytoplasmic proteins of higher molecular weight.The results of this study shows that the increment of the intensity of the PEF treatment did not seem to increase the size of pores of the cytoplasmic membrane of S. cerevisiae and consequentlydid not increase the protein extraction yield. In fact, surpassing a certain threshold may lead to diminished extraction due to the denaturation of proteases that are pivotal in yeast proteinextraction from electroporated yeast cells.