Bouchez M, Blanchet D, Vandecasteele J P
Institut Francais du Pétrole, Division Chimie appliquée, Biotechnologie et Matériaux, Rueil-Malmaison, France.
Appl Microbiol Biotechnol. 1995 Oct;43(5):952-60. doi: 10.1007/BF02431933.
The mechanism of phenanthrene transfer to the bacteria during biodegradation by a Pseudomonas strain was investigated using a sensitive respirometric technique (Sapromat equipment) allowing the quasi-continuous acquisition of data on oxygen consumption. Several systems of phenanthrene supply, crystalline solid and solutions in non-water-miscible solvents (silicone oil and 2,2,4,4,6,8,8-heptamethylnonane) were studied. In all cases, analysis of the kinetics of oxygen consumption demonstrated an initial phase of exponential growth with the same specific growth rate. In order to analyze the second phase of growth and phenanthrene degradation, a study of the kinetics of phenanthrene transfer to the aqueous phase was conducted by direct experimentation, with the crystal and silicone oil systems, in abiotic conditions. The data allowed the validation of a model based on phase-transfer laws, describing the variations, with substrate concentrations, of rates of phenanthrene transfer to the aqueous phase. Analysis of the biodegradation curves then showed that exponential growth ended in all cases when the rates of phenanthrene consumption reached the maximal transfer rates. Thereafter, the biodegradation rates closely obeyed, for all systems, the transfer rate values given by the model. These results unambiguously demonstrated that, in the present case, phenanthrene biodegradation required prior transfer to the aqueous phase. With the silicone oil system, which allowed high transfer and biodegradation rates, phenanthrene was directed towards higher metabolite production and lower mineralization, as shown by oxygen consumption and carbon balance determinations.
利用一种灵敏的呼吸测定技术（Sapromat设备）研究了假单胞菌菌株在生物降解过程中菲向细菌的转移机制，该技术能够准连续获取氧气消耗数据。研究了几种菲供应系统，包括结晶固体以及在与水不混溶的溶剂（硅油和2,2,4,4,6,8,8-庚甲基壬烷）中的溶液。在所有情况下，对氧气消耗动力学的分析都表明存在一个具有相同比生长速率的指数生长初始阶段。为了分析生长的第二阶段和菲的降解情况，通过在非生物条件下对晶体和硅油系统进行直接实验，研究了菲向水相转移的动力学。这些数据验证了一个基于相转移定律的模型，该模型描述了菲向水相转移速率随底物浓度的变化。对生物降解曲线的分析表明，在所有情况下，当菲的消耗速率达到最大转移速率时，指数生长结束。此后，对于所有系统，生物降解速率都紧密遵循模型给出的转移速率值。这些结果明确表明，在当前情况下，菲的生物降解需要先转移到水相中。对于硅油系统，其允许高转移和生物降解速率，通过氧气消耗和碳平衡测定表明，菲导致更高的代谢产物生成和更低的矿化作用。
