Division of Soil and Water Management, Catholic University of Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
Res Microbiol. 2010 Oct;161(8):660-6. doi: 10.1016/j.resmic.2010.06.006. Epub 2010 Jul 1.
We sought to determine whether the pesticide-degrading performance of a multi-species bacterial biofilm is affected by co-occurrence of multiple nutrient sources. Thus, the 3-(3,4-dichlorophenyl)-1-methoxy-1-methyl urea (linuron)-degrading activity of a triple-species linuron-degrading consortium, cultivated in continuous flow biofilm systems, was monitored when exposed to mixed substrate feeds which contained, in addition to linuron, readily assimilated carbon (i.e. citrate and trypticase soy broth) and/or nitrogen (i.e. ammonium) sources. The addition of alternative carbon sources at different concentrations resulted in diminished linuron degradation efficiency. In addition, the efficiency of removal of the linuron metabolite 3,4-dichloroaniline was affected. These effects might be attributed to catabolic repression of the linuron metabolic pathway in the presence of alternative carbon substrates. Moreover, each nutrient condition resulted in a particular biofilm composition and a particular spatial and structural organization, which might also be related to the performance of the biofilm community. Results show that the activity of pesticide-degrading biofilms strongly depends on prevailing nutrient conditions and that the ideal biofilm configuration and activity, as observed under selective conditions, does not exist in real-life environmental conditions where mixtures of substrates are often present.
我们试图确定多物种细菌生物膜的农药降解性能是否会受到多种营养源共存的影响。因此，当暴露于含有除了草丹（linuron）以外的易同化碳（如柠檬酸盐和胰蛋白酶大豆肉汤）和/或氮（如铵）源的混合基质饲料时，我们监测了在连续流动生物膜系统中培养的三物种草丹降解生物群落的 3-(3,4-二氯苯基）-1-甲氧基-1-甲基脲（linuron）降解活性。在不同浓度下添加替代碳源会导致草丹降解效率降低。此外，草丹代谢物 3,4-二氯苯胺的去除效率也受到影响。这些影响可能归因于在存在替代碳底物的情况下，草丹代谢途径的分解代谢抑制。此外，每种营养条件都会导致特定的生物膜组成和特定的空间和结构组织，这也可能与生物膜群落的性能有关。结果表明，农药降解生物膜的活性强烈依赖于流行的营养条件，而且在选择性条件下观察到的理想生物膜结构和活性在现实环境条件下并不存在，因为现实环境中通常存在多种基质混合物。
