Work

Pulsed Electric Field Pretreatment Enhances the Enzyme Hydrolysis of Baker’s Yeast

Year: 2024

Type: article

Abstract: Baker's yeast is a key starting material for producing extracts with diverse compositions and applications. This study investigates the effect of pulsed electric field (PEF) pretreatment, which induces irreversible electropermeabilization, on the enzymatic hydrolysis of yeast. Cell suspensions were exposed to monopolar rectangular pulses in a continuous flow system followed by 4 h of incubation with Alcalase at concentrations of 0.2% and 0.5%. PEF pretreatment significantly improved enzymatic hydrolysis, with maximum intracellular content recovery under electrical conditions resulting in outlet temperatures of 56-58 °C. The released protein reached 163.7 ± 13 mg per gram of dry cell weight (DCW). SDS-PAGE analysis showed that the extracts predominantly contained peptides with molecular masses below 4.7 kDa. The phenolic content was comparable to that of cell lysates obtained after mechanical disruption. The free α-amino nitrogen content and total antioxidant activity reached 218.2 ± 26 mg/gDCW and 53.4 ± 4.6 mg TE/gDCW, respectively, representing 3.2-fold and 2.65-fold increases compared to cell lysates. The hydrolysates from PEF-pretreated cells demonstrated a positive effect on the proliferation of the human keratinocyte cell line HaCat. The obtained data lead to the conclusion that PEF pretreatment is a promising approach to enhance the production of yeast hydrolysates with various applications.

Source: Microorganisms

DOI: 10.3390/microorganisms12122470

Authors: Ralitsa Veleva, Valentina Ganeva, Miroslava Zhiponova

Institution: Sofia University "St. Kliment Ohridski"

Language: English

Topic: Microbial Inactivation Methods

Subfield: Biotechnology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $3,069