Marica D, Rudăreanu N, Kadar I, Todoran L, Rusu A
Facultatea de Medicină Veterinară, Departamentul Microbiologie, Cluj-Napoca.
Bacteriol Virusol Parazitol Epidemiol. 1991 Jan-Jun;36(1):35-42.
The evolution of the methyl rot reaction (MRT), expressed by the pH dynamics in the first 18 hours was examined. A medium made of caseine or soya hydrolysate distributed in small volumes, was experimented versus a control broth made of meat peptone (Clark-Lubs). For Klebsiella the results showed that in the control group the pH acidifies and remains low, thus mimicking a positive reaction. In the caseine/soya medium, a decrease of pH at 4-8 hours is first noticed. Initial acidification, consecutive to glucose fermentation, is then counteracted by another type of processes that change the reaction direction. pH increases at 12-18 hours towards neutrality hat can be easily exceeded in 24 hours. Alkaline reversion is favoured by: a--the richer content in aa diaminomonocarboxylic and b--assurance of a large aeration by increase of the ratio between surface and volume. For evidencing realkalinization, characteristic of Klebsiellae, the medium with caseine/soya, including "ab initio" either Bromkresolpurpur (pH = 5.2-6.2) or Bromtimolblau (pH = 6.7-7.6) is experimented. The medium ensures the direct reading of the reaction, at 18-24 hours, by the colour change. The results correspond to metric pH recording. When the results are not clear (slowly metabolic strains), the culture may be reincubated, an important advantage versus the Clark-Lubs procedure.
研究了通过最初18小时内的pH动态所表示的甲基旋转反应（MRT）的演变。将由酪蛋白或大豆水解产物制成的小体积培养基与由肉蛋白胨制成的对照肉汤（克拉克-卢布斯培养基）进行实验。对于克雷伯菌属，结果表明，在对照组中，pH值酸化并保持在较低水平，从而模拟阳性反应。在酪蛋白/大豆培养基中，首先在4至8小时注意到pH值下降。继葡萄糖发酵后的初始酸化随后被另一种改变反应方向的过程抵消。在12至18小时时pH值向中性增加，在24小时时可能很容易超过中性。碱性逆转受以下因素促进：a. 二氨基单羧酸含量更丰富；b. 通过增加表面积与体积之比确保大量通气。为了证明克雷伯菌属特有的再碱化现象，对含有“初始”溴甲酚紫（pH = 5.2 - 6.2）或溴百里酚蓝（pH = 6.7 - 7.6）的酪蛋白/大豆培养基进行实验。该培养基通过颜色变化确保在18至24小时时直接读取反应结果。结果与pH值的测量记录相符。当结果不明确时（代谢缓慢的菌株），培养物可以重新培养，这相对于克拉克-卢布斯方法是一个重要优势。
