Pulsed electric fields-assisted extraction of molecules from bacterial and yeast cells

Abstract

Electroporation (also termed as pulsed electric field-PEF) has been used in several fields, such as clinics (electrochemotherapy, gene electrotransfer, irreversible tissue ablation, DNA vaccination); food processing (inactivation of microorganisms, drying, extraction of juice from fruits and vegetables); and biotechnology (bacterial electrotransformation, extraction of technologically relevant molecules from microorganisms). Later use of PEF has only started to emerge and the yields of extracted molecules are described to be the same or higher as obtained by other methods. Furthermore, several distinctive advantages over the standard techniques have been described, such as less fragmentation of microorganism and by that less purification needed; no need to use expensive and harmful chemicals and possible selective extraction of molecules. In the introduction, benefits and shortfalls of chemical and physical extraction methods are described. Subsequent sections explore in more detail assisted extraction of different molecules (proteins, plasmid DNA, lipids) by PEF from bacterial and yeast cells. Firstly, instantaneous plasmid DNA (pDNA) extraction/transfer from/ into various species is described, where different parameters have been studied in order to obtain as much successfully transformed cells as possible. Later sections present an overview of the parameters affecting the efficiency of extraction assisted by PEF. At the end main parameters affecting the yield of extracted molecules are summarized and main challenges of PEF-assisted extraction of molecules from microorganisms are presented.