Table 3.

Overview of microbial inactivation by non-thermal plasma.

Device	Gas	Voltage	Microorganisms	Main Result	Ref.
Dielectric barrier discharge	He	RF 1 voltage at about 45 MHz	P. aeruginosa S. aureus Bacterial biofilms	ROS/RNS accumulation Membrane depolarization	[108]
Floating-electrode dielectric-barrier discharge (FE-DBD)	Air	low-frequency alternating current (120 V)	E coli S. aureus methicillin-resistant Staphylococcus aureus (MRSA)	Decreasing in viability in both bacterial form (planktonic and biofilm)	[109]
miniFlatPlaSter	Air	7 kV	S. aureus MRSA E. coli	Decolonization of S. aureus MRSA, E. coli in time-dependent manner	[110]
FlatPlaSter	Air	9 kV	S. aureus MRSA E. coli	Decolonization of S. aureus MRSA and E. coli in time-dependent manner	[110]
Surface Micro-Discharge (SMD) plasma	Air	10 kV	E. coli K12 E. coli B. cepacia P. aeruginosa Gram-positive bacteria S. aureus MRSA S. epidermidis E. faecalis E. mundtii B. cereus B. pumilus C. difficile S. pyogenes C. jeikeium C. albicans	The antimicrobial effects of SMD on various vegetative MO and endospores in time-dependent manner	[111]
Plasma jet	Air or Ar	5.5 kV for air 4–5 kV for Ar	E.coli	Air plasma: completely rupture of cell walls, inactivation of bacteria by the influence of oxidative stress on peptidoglycans and lipids in the cell wall and membrane	[112]
Terraplasma GmbH, Garching, Germany	Air	6.4 kV and 10 kV	S. enterica S. Typhimurium L. monocytogenes	Analysis of 4 plasma modes several properties of ham colonized by bacteria post treated with plasma as well as after storage	[113]
Discharge plasma device	He	10 kV	S. aureus B. subtilis E.coli P. aeruginosa	Dose-dependent decrease in viability of all the bacterial strains, morphological changes after 60 sec of NTP treatment	[114]
Plasma discharge manufactured by Sominex	O2, N2 and Ar	-	P. aeruginosa S. aureus B. subtilis	Dose- dependent reduction of viability in all three studied vegetative form of bacteria, together with morphologic and structural changes of spores	[115]
Discharge plasma device	He	0.5 kV10 kV	S. aureus B. subtilis E.coli P. aeruginosa	Dose-dependent effects of NTP In low-voltage mode activation of programmed cell death after 15 sec In higher-voltage mode more profound damage of bacteria and physical destruction	[116]
DBD system	Air	80 kV	E. coli S.aureus	Time-dependent inactivation of both bacterial strains increased level of ROS accumulation, Possible mechanism of bacterial inactivation different between gram positive and gram negative bacteria, leakage of membrane in E. coli after plasma treatment	[117]
DBD system	Air	18.6 kV	S. aureus P. aeruginosa C. albicans	Rapid inactivation of antibiotic- resistant MO, surface alternation and permeabilization of membrane, depletion of intracellular ATP production, minor changes on DNA and proteins level	[118]
APPJ	N2 gas in combination with different flow rates of H2O/HNO3 solution	2.2 kV	E. coli	Effects of plasma treated water (PTW) on E. coli viability, effect of chemical composition of PTW importance of NO2- and H2O2 for antimicrobial activity, analysis of oxidative related gene expression, DNA damage and cell morphology upon PTW treatment	[119]
DBD system	Air or argon (Ar)	0.75 kV	F. oxysporum f.sp. lycopersici spores	Time-dependent cell death (both apoptosis and necrosis) in Fusarium oxysporum f.sp. lycopersici spores post plasma treatment. Reduction of germination ratesWithout any effect of host plant health or growth	[120]
DBD system	Air	80 kV	P. aeruginosa quorum sensing (QS)-regulated virulence factors, E. coli, L. monocytogenes and S. aureus for biofilm formation	Significant time-dependent reduction of bacterial biofilm in all three studied strains after both direct and indirect NTP treatment Disintegrated cell walls Decreasing in concentration of (QS)-regulated virulence factors (pyocyanin and elastase)	[121]
DBD system	Air in combination with 90% N2 + 10% O2	56 kV and 70 kV	L. monocytogenes E.coli	Time- dependent MO inactivation, increased with higher voltage level Dose-dependent accumulation of DNA damage and impaired membrane integrity Higher resistance of gram-negative E. coli in comparison with L. monocytogenes	[122]

¹ RF—radio frequency.