Kunc F, Rybárová J
Folia Microbiol (Praha). 1984;29(2):156-61. doi: 10.1007/BF02872932.
Samples of chernozem soil were enriched with vanillic acid, protocatechuic acid glucose, a mixture of glucose and (NH4)2SO4 (C : N = 5 : 1), ethanol and 2,4-dichlorophenoxyacetic acid (2,4-D). After a 6-d (with 2,4-D 35-d) incubation during which primary oxidation of the introduced substrates occurred, the soil was supplied with a solution of 2-14C-2,4-D (50 ppm; 6.7 kBq) and production of 14CO2 (product of microbial degradation of 2,4-D) was measured. Previously enriched samples exhibited a higher degradation rate; both the lag phase and doubling time of mineralization activity in the exponential phase of the process were markedly higher. This reflected an overall proliferation of bacteria and the increased relative proportion of bacterial strains capable of mineralizing 2,4-D in enriched samples. The stimulation of 2,4-D degradation may involve specific adaptation and selection mechanisms (as in the case with samples previously enriched with 2,4-D or its structural analogues--aromatic monomers, ethanol) as well as non-specific mechanisms. The extent of mineralization of 2,4-D was not affected by soil pretreatment, about 1/3 of introduced radioactive carbon being invariably transformed to 14CO2.
黑钙土样本用香草酸、原儿茶酸葡萄糖、葡萄糖与硫酸铵的混合物（碳氮比为5:1）、乙醇和2,4-二氯苯氧乙酸（2,4-D）进行富集。在进行了6天（对于2,4-D为35天）的培养后，在此期间引入的底物发生了初级氧化，向土壤中加入2-¹⁴C-2,4-D溶液（50 ppm；6.7 kBq），并测量¹⁴CO₂（2,4-D微生物降解产物）的产生量。先前富集的样本表现出更高的降解速率；该过程指数期的矿化活性的滞后期和倍增时间均明显更短。这反映了细菌的总体增殖以及富集样本中能够矿化2,4-D的细菌菌株相对比例的增加。2,4-D降解的刺激可能涉及特定的适应和选择机制（如先前用2,4-D或其结构类似物——芳香单体、乙醇富集的样本情况）以及非特定机制。2,4-D的矿化程度不受土壤预处理的影响，引入的放射性碳约有1/3总是转化为¹⁴CO₂。
