Barriault D, Sylvestre M
Université du Québec, Institut national de la recherche scientifique-Santé, Pointe-Claire, Canada.
Can J Microbiol. 1993 Jun;39(6):594-602. doi: 10.1139/m93-086.
Pseudomonas testosteroni B-356 was able to degrade approximately 50% of the Aroclor 1242 mixture in shaken culture. The aims of the present study were to evaluate the capabilities of this bacterial strain to degrade PCBs in soil microcosms and to identify some of the factors likely to favor the degradative performance of the implanted bacteria. The presence of biphenyl as cosubstrate was the most important factor affecting PCB degradation in soil. However, because biphenyl was rapidly depleted in soil microcosms, repeated addition of small amounts of biphenyl to maintain a constant level of the cosubstrate allowed the achievement of a higher degree of degradation of the tetrachlorinated components of Aroclor 1242 than was achieved with a single addition at the time of inoculation. Degradation of di- and tri-chlorinated PCB congeners was less affected by repeated addition of biphenyl because these congeners were degraded very fast and complete degradation was achieved before biphenyl was depleted in the soil. Biodegradation was also related to bioavailability of the substrate. We observed that the proportion of each congener degraded was higher in the microcosms receiving both the producer of the surface-active agent, Alcaligenes faecalis B-556, and strain B-356. Under the best conditions (presence of a constant level of biphenyl and of strain B-556) P. testosteroni B-356 was able to degrade approximately 30% of the Aroclor 1242 added to soil microcosms; some other factors reducing the PCB degradation capabilities of the implanted bacteria are also discussed.
睾丸酮假单胞菌B - 356在摇瓶培养中能够降解大约50%的氯丹1242混合物。本研究的目的是评估该菌株在土壤微观系统中降解多氯联苯的能力，并确定一些可能有利于植入细菌降解性能的因素。联苯作为共底物的存在是影响土壤中多氯联苯降解的最重要因素。然而，由于联苯在土壤微观系统中迅速耗尽，通过反复添加少量联苯以维持共底物的恒定水平，与接种时一次性添加相比，能够实现对氯丹1242中四氯化成分更高程度的降解。反复添加联苯对二氯和三氯多氯联苯同系物的降解影响较小，因为这些同系物降解非常快，在土壤中联苯耗尽之前就实现了完全降解。生物降解还与底物的生物利用度有关。我们观察到，在同时接种表面活性剂产生菌粪产碱菌B - 556和菌株B - 356的微观系统中，每种同系物的降解比例更高。在最佳条件下（存在恒定水平的联苯和菌株B - 556），睾丸酮假单胞菌B - 356能够降解添加到土壤微观系统中的大约30%的氯丹1242；还讨论了其他一些降低植入细菌多氯联苯降解能力的因素。
