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Archives of Industrial Biotechnology | Volume 2
May 14-15, 2018 | Montreal, Canada
World Yeast Congress
S
accharomyces cerevisiae
is one of the most well-studied
and understood eukaryotic organisms. The studies
of yeast cell allow reconstitution of possible molecular
mechanisms of various abiotic effects. Pulsed electric field
has been one of the most intensively investigated abiotic
effects on biological tissues and cell suspensions for a past
decade. It has been previously shown that a nanosecond
pulsed electric field (nsPEF) permeabilize the plasma
membrane, alter gene expression, cause phosphatidylserine
translocation, affect the distribution of intracellular ions
and even lead to the death of mammalian cells. There is still
a lack of sufficient data related to the effects of nsPEF on
yeast cells yet. In our study we analyzed the effects of square
shaped electrical pulses of different duration (τ= 10-90 ns)
and pulse number (pn= 1-5) with electric field strength (E)
up to 220 kV/cm and showed that nanosecond pulses can
induce the cell death, which in turn is dependent on the
electric field pulse parameters and increase with the rise
in E, τ and pulse number. Exposure of yeast cells to nsPEFs
was accompanied by metacaspase activation, membrane
permeability to propidium iodide and the externalization
of phosphatidylserine. Furthermore, the investigation of
yeast cells permeabilization to tetraphenylphosphonium
ions (TPP+), which was induced by high power nanosecond
duration electrical pulses, had demonstrated the following
features: (i) The study of TPP+ ions absorption rate by yeast
cells is an effective method for detection of short duration
electric pulse influence on yeast cell wall properties; (ii)
Shortening of the electric pulse duration makes it possible
to achieve more homogeneous electrical treatment of yeast
cell clusters and by this way to increase the effectiveness of
single cell permeabilization; (iii) The significant acceleration
of TPP+ ions absorption rate (up to 65 times) can be
achieved without any influence on the vitality of the cells.
We conclude that square shaped electric field pulses with
nanosecond durations induce wide variety of effects
including caspase-dependent apoptosis, oxidative stress,
cell wall permeabilization, and that such abiotic treatment
can be used in various applications starting from food safety
ensurance and ending in medicine field.
Speaker Biography
Povilas Šimonis has finished master studies Biochemistry (Vilnius University) and
started his Chemistry PhD (Center for Physical Sciences and Technology) in 2016. During
his scientific career he participated in various schools related to application of pulsed
electric fields including: EBTT – international scientific workshop and postgraduate
course, school on applications of Pulsed Electric Fields for food processing. He is a
member of ISEBTT (International Society of Electroporation – Based Technologies and
Treatments). Presented his working results in more than 10 local and international
conferences. Currently his scientific data is already published in Bioelectrochemistry
Journal.
e:
simonis.povilas@gmail.comThe effects of nanosecond pulsed electric fields on
Saccharomyces cerevisiae
cells
Povilas Šimonis
Center for Physical Sciences and Technology, Lithuania