High-voltage pulsed electric field laboratory device with asymmetric voltage multiplier for marine macroalgae electroporation

Abstract

Optimization of protocols is required for each specific type of biomass processed by electroporation of the cell membrane with high voltage pulsed electric fields (PEF). Such optimization requires convenient and adaptable laboratory systems, which will enable determination of both electrical and mechanical parameters for successful electroporation and fractionation. In this work, we report on a laboratory PEF system consisting of a high voltage generator with a novel asymmetric voltage multiplying architecture and a treatment chamber with sliding electrodes. The system allows applying 29 pulses of up to 4 kV and 1 kA with a pulse duration between 1 μs and 100 μs. The allowable energy 30 dissipated per pulse on electroporated biomass is determined by the conditions for cooling the biomass in the electroporation cell. The device was tested on highly conductive green macroalgae 32 from Ulva sp., a promising but challenging feedstock for the biorefinery. Successful electroporation 33 was confirmed with bioimpedance measurements. Industrial relevanceSeaweed biomass is an emerging feedstock for biorefineries with already 30 million tons per year of global industrial production. However, most of the biomass produced today is lost. Pulsed electric field (PEF) extraction could allow saving energy on biomass drying, deashing and it could allow extracting various organic compounds. However, the parameters needed to seaweed biomass treatment with PEF are not known and will differ from species to species. Furthermore, very high salt content challenges most of the available laboratory PEF devices, limiting the ability for parameters optimization in the lab. The developed laboratory scale PEF system coupled to bioimpedance measurement provides a necessary set of tools and methods for PEF parameters optimization required for process scale-up.

Does the shape of the electric pulse matter in electroporation?

“…For example, Grainys et al have developed a high-voltage, bipolar electroporator that generates single or multiple, symmetrical or asymmetrical, high-power square wave microsecond pulses up to ±1 kV and 100 A (113). Levkov et al reported on a PEF system consisting of a high-voltage generator with an asymmetric voltage multiplying architecture and a treatment chamber with sliding electrodes for marine macroalgae electroporation (114). The system enables pulses of up to 4 kV and 1 kA with a pulse duration between 1 ms and 100 ms.…”

“…Levkov et al. reported on a PEF system consisting of a high-voltage generator with an asymmetric voltage multiplying architecture and a treatment chamber with sliding electrodes for marine macroalgae electroporation ( 114 ). The system enables pulses of up to 4 kV and 1 kA with a pulse duration between 1 μs and 100 μs.…”

Extracting Water-Soluble Proteins from the Red Macroalgae Gracilaria sp. with Pulsed Electric Field in a Continuous Process

“…The custom-made HVPG electric device used in this study was described in detail in our previous works. 15,30,34 The functional scheme of the HVPG is presented in Figure 2a, and the design of the HVPG is shown in Figure 2b; the interaction of functional units is described in the work algorithm of the device. The novel mechanical parts of the continuous PEF device especially designed and constructed in this study are shown in Figure 3.…”

“…However, all PEF studies known to us on seaweeds have been done in batch systems. ,− PEF process development on other types of biomasses showed that the transition from batch to continuous processes, which is desirable for the industry, is possible but challenging . Among many challenges, there is a need for equipment development for a continuous PEF process and for process condition optimization .…”

Non-Thermal Methods for Ensuring the Microbiological Quality and Safety of Seafood

“…In fish processing, PEF treatment is also applied to improve the extraction of various organic compounds from fish and seafood [180][181][182][183]. Franco et al (2020) [184] recommended the use of PEF treatment for improved antioxidant extraction from fish residues (gills, bones, and heads) of two commercial species (sea bream and sea bass).…”