Bonde M R, Nester S E, Schaad N W, Frederick R D, Luster D G
USDA-ARS, Foreign DiseaseWeed Science Research Unit, Fort Detrick, MD 21702.
Plant Dis. 2003 Jun;87(6):712-718. doi: 10.1094/PDIS.2003.87.6.712.
Acidic electrolyzed water (AEW) is a germicidal product of electrolysis of a dilute solution (e.g., 0.4% vol/vol) of sodium chloride. This solution can be used to disinfest wheat seed or soil samples being tested for teliospores of Tilletia indica, causal agent of Karnal bunt, without risk of damaging the teliospores. The AEW used in this study had a pH of 2.5 to 2.8 and oxidation-reduction potential of approximately 1,130 mV. In simulations of routine extractions of wheat seed to detect teliospores of T. indica, the effectiveness of a 30-min AEW treatment was compared with a 2-min 0.4% sodium hypochlorite (NaOCl) treatment to eradicate bacteria and nonsmut fungi. Each treatment reduced bacterial and fungal populations in wheat seed extracts by 6 to 7 log units when determined on 2% water agar with antibiotics. Reductions of 5 log units or more were observed on other media. NaOCl and AEW also were very effective at eliminating bacteria and fungi from soil extracts. In studies to detect and quantitate T. indica teliospores in soil, AEW was nearly 100% effective at eliminating all nonsmut organisms. Free chlorine levels in AEW were very low, suggesting that compounds other than those with chlorine play a significant role in sanitation by AEW. The low pH of AEW was shown to contribute substantially to the effectiveness of AEW to reduce microorganisms. A standardized protocol is described for a 30-min AEW treatment of wheat seed washes or soil extracts to eliminate contaminating microorganisms. A significant advantage of the use of AEW over NaOCl is that, with AEW, teliospore germination is not reduced and usually is stimulated, whereas teliospore germination declines after contact with NaOCl. The protocol facilitates detection and enumeration of viable teliospores of T. indica in wheat seed or soil and the isolation of pure cultures for identification by polymerase chain reaction. The germicidal effects of AEW, as demonstrated in this study, illustrate the potential of AEW as an alternative to presently used seed disinfestants.
酸性电解水（AEW）是氯化钠稀溶液（如0.4%体积/体积）电解产生的一种杀菌产品。该溶液可用于对正在检测印度腥黑粉菌冬孢子的小麦种子或土壤样本进行除害处理，印度腥黑粉菌是 Karnal 腥黑穗病的病原体，且不会有损坏冬孢子的风险。本研究中使用的AEW的pH值为2.5至2.8，氧化还原电位约为1130 mV。在模拟检测印度腥黑粉菌冬孢子的小麦种子常规提取过程中，将30分钟的AEW处理效果与2分钟的0.4%次氯酸钠（NaOCl）处理效果进行比较，以根除细菌和非黑粉菌真菌。当在添加抗生素的2%水琼脂上测定时，每种处理均使小麦种子提取物中的细菌和真菌数量减少6至7个对数单位。在其他培养基上观察到减少了5个或更多对数单位。NaOCl和AEW在消除土壤提取物中的细菌和真菌方面也非常有效。在检测和定量土壤中印度腥黑粉菌冬孢子的研究中，AEW在消除所有非黑粉菌生物方面几乎100%有效。AEW中的游离氯水平非常低，这表明除含氯化合物外的其他化合物在AEW的卫生处理中起重要作用。结果表明，AEW的低pH值对其减少微生物的有效性有很大贡献。本文描述了一种标准化方案，用于对小麦种子冲洗液或土壤提取物进行30分钟的AEW处理，以消除污染微生物。与NaOCl相比，使用AEW的一个显著优点是，使用AEW时，冬孢子萌发不会降低，通常还会受到刺激，而与NaOCl接触后冬孢子萌发会下降。该方案有助于检测和计数小麦种子或土壤中印度腥黑粉菌的活冬孢子，并分离纯培养物以通过聚合酶链反应进行鉴定。本研究中证明的AEW的杀菌作用说明了AEW作为目前使用的种子消毒剂替代品的潜力。
