Inactivation of Bacillus subtilis Spores in Water by a Direct-Current, Cold Atmospheric-Pressure Air Plasma Microjet

• Published in: Plasma processes and polymers 2012-02, Vol.9 (2), p.157-164
• Main Authors: Sun, Peng, Wu, Haiyan, Bai, Na, Zhou, Haixia, Wang, Ruixue, Feng, Hongqing, Zhu, Weidong, Zhang, Jue, Fang, Jing
• Format: Article
• Language: English
• Subjects: Bacillus subtilis; electron spin resonance; Exact sciences and technology; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; plasma activated water; Plasma applications; plasma microjet
• ISSN: 1612-8850; 1612-8869
• DOI: 10.1002/ppap.201100041

Bacillus subtilis spores suspended in distilled water was effectively inactivated in 6 min by a direct‐current atmospheric pressure non‐thermal air plasma microjet. Scanning electron microscopic images show clear distortion and debris of spores after plasma treatment. Direct contribution by temperature and pH change of water as well as relatively long lived species in plasma activated water (PAW) is excluded. Short lived species (such as •OH, •O 2− and O2(1Δg)) are detected in the plasma‐water system by electron spin resonance spectroscopy, and are considered to be the most important agents in the inactivation process. B. subtilis spores in water were effectively inactivated in 6 min by a DC air plasma microjet. SEM images show clear distortion and debris of spores after plasma treatment. Short lived species (such as •OH, •O 2− and O2(1Δg)) are detected in the plasma‐water system by ESR spectroscopy, and are considered to be the most important agents in the inactivation process. Direct contribution from temperature, pH and long lived species are excluded.