Setlow B, Loshon C A, Genest P C, Cowan A E, Setlow C, Setlow P
Department of Biochemistry, University of Connecticut Health Center, Farmington, CT 06030, USA.
J Appl Microbiol. 2002;92(2):362-75. doi: 10.1046/j.1365-2672.2002.01540.x.
To determine the mechanisms of killing of Bacillus subtilis spores by ethanol or strong acid or alkali.
Killing of B. subtilis spores by ethanol or strong acid or alkali was not through DNA damage and the spore coats did not protect spores against these agents. Spores treated with ethanol or acid released their dipicolinic acid (DPA) in parallel with spore killing and the core wet density of ethanol- or acid-killed spores fell to a value close to that for untreated spores lacking DPA. The core regions of spores killed by these two agents were stained by nucleic acid stains that do not penetrate into the core of untreated spores and acid-killed spores appeared to have ruptured. Spores killed by these two agents also did not germinate in nutrient and non-nutrient germinants and were not recovered by lysozyme treatment. Spores killed by alkali did not lose their DPA, did not exhibit a decrease in their core wet density and their cores were not stained by nucleic acid stains. Alkali-killed spores released their DPA upon initiation of spore germination, but did not initiate metabolism and degraded their cortex very poorly. However, spores apparently killed by alkali were recovered by lysozyme treatment.
The data suggest that spore killing by ethanol and strong acid involves the disruption of a spore permeability barrier, while spore killing by strong alkali is due to the inactivation of spore cortex lytic enzymes.
The results provide further information on the mechanisms of spore killing by various chemicals.
确定乙醇、强酸或强碱杀灭枯草芽孢杆菌孢子的机制。
乙醇、强酸或强碱杀灭枯草芽孢杆菌孢子并非通过DNA损伤，且孢子外壁不能保护孢子免受这些试剂的影响。用乙醇或酸处理的孢子释放其吡啶二羧酸（DPA）的过程与孢子杀灭过程同步，乙醇或酸处理杀死的孢子的核心湿密度降至接近缺乏DPA的未处理孢子的数值。被这两种试剂杀死的孢子的核心区域被核酸染料染色，而这些染料不会渗入未处理孢子的核心，且酸处理杀死的孢子似乎已经破裂。被这两种试剂杀死的孢子在营养和非营养萌发剂中也不会萌发，并且不能通过溶菌酶处理回收。被碱杀死的孢子不会失去其DPA，其核心湿密度也不会降低，并且其核心不会被核酸染料染色。碱处理杀死的孢子在孢子萌发开始时释放其DPA，但不会启动新陈代谢，并且其皮层降解非常差。然而，明显被碱杀死的孢子可通过溶菌酶处理回收。
数据表明，乙醇和强酸杀灭孢子涉及孢子通透性屏障的破坏，而强碱杀灭孢子是由于孢子皮层裂解酶的失活。
结果提供了关于各种化学物质杀灭孢子机制的进一步信息。
