Heitkamp M A, Freeman J P, Cerniglia C E
Appl Environ Microbiol. 1986 Feb;51(2):316-22. doi: 10.1128/aem.51.2.316-322.1986.
The biodegradation of tert-butylphenyl diphenyl phosphate (BPDP) was examined in microcosms containing sediment and water from five different ecosystems as part of our studies to elucidate the environmental fate of phosphate ester flame retardants. Biodegradation of [14C]BPDP was monitored in the environmental microcosms by measuring the evolution of 14CO2. Over 37% of BPDP was mineralized after 8 weeks in microcosms from an ecosystem which had chronic exposure to agricultural chemicals. In contrast, only 1.7% of BPDP was degraded to 14CO2 in samples collected from a noncontaminated site. The exposure concentration of BPDP affected the percentage which was degraded to 14CO2 in microcosms from the two most active ecosystems. Mineralization was highest at a concentration of 0.1 mg of BPDP and was inhibited with 10- and 100-fold higher concentrations of BPDP in these microcosms. Indigenous heterotrophic and BPDP-utilizing microbial populations and phosphoesterase enzyme activities were highest in sediments which had the highest biodegradation of BPDP. We observed adaptive increases in both microbial populations and phosphoesterase enzymes in some sediments acclimated to BPDP. Chemical analyses of the residues in the microcosms indicated undegraded BPDP and minor amounts of phenol, tert-butylphenol, diphenyl phosphate, and triphenyl phosphate as biodegradation products. These data suggest that the microbial degradation of BPDP results from at least three catabolic processes and is highest when low concentrations of BPDP are exposed to sediment microorganisms of eutrophic ecosystems which have high phosphotri- and diesterase activities and previous exposure to anthropogenic chemicals.
作为我们阐明磷酸酯阻燃剂环境归宿研究的一部分，我们在含有来自五个不同生态系统的沉积物和水的微观世界中研究了磷酸三叔丁基苯二苯酯（BPDP）的生物降解情况。通过测量(^{14}CO_2)的释放量来监测环境微观世界中([^{14}C]BPDP)的生物降解。在一个长期接触农用化学品的生态系统的微观世界中，8周后超过37%的BPDP被矿化。相比之下，从一个未受污染的地点采集的样本中，只有1.7%的BPDP降解为(^{14}CO_2)。BPDP的暴露浓度影响了来自两个最活跃生态系统的微观世界中降解为(^{14}CO_2)的百分比。在这些微观世界中，当BPDP浓度为0.1毫克时矿化率最高，而浓度高出10倍和100倍时则受到抑制。在BPDP生物降解率最高的沉积物中，本地异养和利用BPDP的微生物种群以及磷酸酯酶活性最高。我们观察到，在一些适应BPDP的沉积物中，微生物种群和磷酸酯酶都有适应性增加。对微观世界中残留物的化学分析表明，有未降解的BPDP以及少量作为生物降解产物的苯酚、叔丁基苯酚、磷酸二苯酯和磷酸三苯酯。这些数据表明，BPDP的微生物降解至少源于三种分解代谢过程，并且当低浓度的BPDP暴露于富营养生态系统中具有高磷酸三酯酶和二酯酶活性且先前接触过人为化学品的沉积物微生物时，降解率最高。
