Growth rates of a pseudomonad on 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol.
Growth rates of a pseudomonad on 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol.
复制标题
假单胞菌在 2,4-二氯苯氧基乙酸和 2,4-二氯苯酚上的生长速率。
DOI：
10.1128/aem.28.2.181-184.1974
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发表时间：
1974
期刊：
影响因子：
--
通讯作者：
R. K. Finn
中科院分区：
文献类型：
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作者：
J. E. Tyler;R. K. Finn
研究了一种假单胞菌在2,4-d（2,4-二氯苯氧乙酸）和2,4- dcp（2,4-二氯酚）上的分批培养和连续培养。2,4- d的最佳生长速率为0.14/h，温度为25℃，pH值为6.2 ~ 6.9。使用2,4- dcp，在25℃条件下，pH范围为7.1 ~ 7.8，比生长率最高为0.12/h。2,4- dcp浓度超过25毫克/升时，对生长有强烈抑制作用，而2,4- d浓度达到2,000毫克/升时，则没有明显的抑制作用。在亚抑制浓度下，2,4- dcp的生长由Monod动力学描述，但2,4- dcp的抑制对底物浓度表现出不同寻常的线性响应，并且不符合基于非竞争性抑制的模型。发现批培养的滞后期取决于2,4- dcp浓度和接种物的预先适应。在相关底物上的生长动力学方面的研究可以作为在代谢序列中寻找限速步骤的一种方法。
The growth of a pseudomonad on 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4-DCP (2,4-dichlorophenol) was studied in batch and continuous culture. The optimum growth rate using 2,4-D was 0.14/h at 25 C in a pH range from 6.2 to 6.9. Highest specific growth rate using 2,4-DCP was 0.12/h at 25 C in a pH range from 7.1 to 7.8. Growth was strongly inhibited by 2,4-DCP above a concentration of 25 mg/liter whereas no appreciable inhibition was observed with 2,4-D at concentrations up to 2,000 mg per liter. Growth on 2,4-DCP was described by Monod kinetics at subinhibitory concentrations but the inhibition by 2,4-DCP exhibited an unusual linear response to substrate concentration, and did not fit a model based on noncompetitive inhibition. The lag phase of batch cultures was found to depend on both 2,4-DCP concentration and prior adaptation of the inoculum. A study such as this on the kinetics of growth on related substrates may be useful as a method of finding the rate-limiting step in a metabolic sequence.