Ward G D, Watson I A, Stewart-Tull D E, Wardlaw A C, Chatwin C R
Division of Infection and Immunity, University of Glasgow, UK.
Lett Appl Microbiol. 1996 Sep;23(3):136-40. doi: 10.1111/j.1472-765x.1996.tb00049.x.
Near infrared light from a high-powered, 1064 nm, Neodymium:Yttrium Aluminium Garnet (Nd:YAG) laser killed a variety of Gram-positive and Gram-negative bacteria and two yeasts, lawned on nutrient agar plates. A beam (cross-sectional area, 1.65 cm2) of laser light was delivered in 10 J, 8 ms pulses at 10 Hz, in a series of exposure times. For each microbial species, a dose/response curve was obtained of area of inactivation vs energy density (J cm-2). The energy density that gave an inactivation area (IA) equal to 50% of the beam area was designated the IA50-value and was plotted together with its 95% confidence limits. Average IA50-values were all within a threefold range and varied from 1768 J cm-2 for Serratia marcescens to 4489 J cm-2 for vegetative cells of Bacillus stearothermophilus. There were no systematic differences in sensitivity attributable to cell shape, size, pigmentation or Gram reaction. At the lowest energy densities where inactivation was achieved for the majority of organisms (around 2000 J cm-2), no effect was observed on the nutrient agar surface, but as the energy density was increased, a depression in the agar surface was formed, followed by localized melting of the agar.
来自高功率1064纳米钕钇铝石榴石（Nd:YAG）激光的近红外光杀死了接种在营养琼脂平板上的多种革兰氏阳性菌、革兰氏阴性菌以及两种酵母。一束激光（横截面积1.65平方厘米）以10赫兹的频率，在一系列曝光时间内以10焦耳、8毫秒的脉冲形式发射。对于每种微生物，获得了失活面积与能量密度（焦耳/平方厘米）的剂量-反应曲线。将导致失活面积（IA）等于光束面积50%的能量密度指定为IA50值，并绘制出其95%置信区间。平均IA50值均在三倍范围内，从粘质沙雷氏菌的1768焦耳/平方厘米到嗜热脂肪芽孢杆菌营养细胞的4489焦耳/平方厘米不等。在细胞形状、大小、色素沉着或革兰氏反应方面，敏感性没有系统性差异。在大多数生物体实现失活的最低能量密度（约2000焦耳/平方厘米）下，未观察到营养琼脂表面有任何影响，但随着能量密度的增加，琼脂表面出现凹陷，随后琼脂局部熔化。
