Disruption and protein release by ultrasonication of yeast cells

Protein is an important intracellular component of yeast cells with many beneficial functions to human health. In this study, disruption and protein releasing kinetics of Saccharomyces cerevisiae cells were investigated using an ultrasonic probe system. The effects of acoustic power and duty cycle of a sonicator on cell disruption and protein release were examined. The efficiency of cell disruption was evaluated by measurements of electrical conductivity, UV-spectroscopy and cell size. Higher degree of cell disruption was observed with increasing acoustic power and duty cycle. The relationship between protein release and cycle time at various process conditions was studied; and the data were fit to a first order kinetic expression. The analysis of these kinetic data led to the proposing of a simple model for protein releasing kinetics that involves acoustic power and duty cycle as parameters. Finally, different sonication systems have been compared, with the bath-type sonicator being less effective for yeast cell disruption and protein release compared to horn-type sonicator. Industrial relevance: The cytoplasm of (S. cerevisiae) yeast cell is a rich source of bio-products (proteins, cytoplasmic enzymes, polysaccharides, etc.) valuable for the food industry. For good recovery of these intracellular bio-products, efficient breakage of the cell walls is a necessary step. In this study, disruption and protein releasing kinetics of S. cerevisiae cells were investigated using an ultrasonic probe system. (C) 2013 Elsevier Ltd. All rights reserved.