Bonn W G, Sequeira L
Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin 53706.
Plant Physiol. 1975 Nov;56(5):688-91. doi: 10.1104/pp.56.5.688.
A tube culture system was designed for measurement of ethylene evolved by the phytopathogenic bacterium, Pseudomonas solanacearum. The system consisted of 10 glass tubes joined together in series and coated on the inside surface with a dextrose-peptone-casamino acids agar medium. The system provided a large surface for bacterial growth in relation to the volume of air. The system was seeded with a bacterial suspension (7 x 10(8) cells/ml) drawn through all the tubes by vacuum applied at one end and was then placed in a water bath at 30 C. Air was pumped through the system at 3 ml/min; the outlet was connected directly to the inlet port of a gas sampling loop and ethylene in the sample was determined by gas chromatography.Maximum rate of ethylene production for a fluidal, virulent isolate of P. solanacearum (K60) was 5.5 x 10(-9) moles/min and occurred at the end of lag phase and beginning of stationary phase. Three other fluidal isolates produced ethylene at relatively low rates (2.4-6.4% that of K60). Avirulent, butyrous variants of these isolates grew as well as the virulent forms in most cases, but ethylene production rates per cell were much lower for the avirulent than for the virulent forms. Loss of virulence appears to be accompanied by lower ethylene production.Peak CO(2) production (14.5 mumoles/min) and O(2) consumption (11.7 mumoles/min) for isolate K60 also occurred at the time when the bacterial culture was entering stationary phase. The concentrations of O(2) (11%) and CO(2) (11%) in air present at this time were thought to be neither limiting nor inhibitory to bacterial growth.
设计了一种试管培养系统，用于测量植物病原菌茄科青枯雷尔氏菌（Pseudomonas solanacearum）释放的乙烯。该系统由10根玻璃试管串联而成，内表面涂有葡萄糖 - 蛋白胨 - 酪蛋白氨基酸琼脂培养基。相对于空气体积，该系统为细菌生长提供了较大的表面积。通过在一端施加真空，将细菌悬浮液（7×10⁸ 个细胞/毫升）抽吸通过所有试管，从而接种该系统，然后将其置于30℃的水浴中。以3毫升/分钟的速度将空气泵入该系统；出口直接连接到气体采样环的入口端口，通过气相色谱法测定样品中的乙烯。茄科青枯雷尔氏菌（K60）的一个光滑、致病菌株产生乙烯的最大速率为5.5×10⁻⁹ 摩尔/分钟，发生在延滞期末期和稳定期初期。其他三个光滑菌株产生乙烯的速率相对较低（为K60的2.4 - 6.4%）。这些菌株的无毒、奶油状变体在大多数情况下与致病形式生长情况相同，但无毒形式的每个细胞乙烯产生速率远低于致病形式。毒力丧失似乎伴随着乙烯产生量降低。菌株K60的二氧化碳产生峰值（14.5微摩尔/分钟）和氧气消耗峰值（11.7微摩尔/分钟）也出现在细菌培养进入稳定期时。此时空气中的氧气浓度（11%）和二氧化碳浓度（11%）被认为对细菌生长既无限制作用也无抑制作用。
