Division of Soil and Water Management, KU Leuven, Leuven, Belgium.
Appl Environ Microbiol. 2012 Apr;78(8):2783-9. doi: 10.1128/AEM.06991-11. Epub 2012 Feb 3.
libA, a gene encoding a novel type of linuron hydrolase, was recently identified in the linuron-mineralizing Variovorax sp. strain SRS16. In order to assess the contribution of libA to linuron degradation in environmental settings, libA abundance was monitored in response to the application of linuron and to environmental perturbations in agricultural soil microcosms and microcosms simulating the matrix of on-farm biopurification systems. libA numbers were measured by real-time PCR and linked to reported data of Variovorax community composition and linuron mineralization capacity. In the soil microcosms and one biopurification system setup, libA numbers responded to the application of linuron and environmental changes in congruency with the modulation of linuron mineralization capacity and the occurrence of a particular Variovorax phylotype (phylotype A). However, in another biopurification system setup, no such correlations were found. Our data suggest that in the simulated environmental settings, the occurrence of libA can be linked to the linuron mineralization capacity and that libA is primarily hosted by Variovorax phylotype A strains. However, the results also suggest that, apart from libA, other, as-yet-unknown isofunctional genes play an important role in linuron mineralization in the environment.
libA 是一个基因，编码一种新型的敌草隆水解酶，最近在敌草隆矿化的鞘氨醇单胞菌 SRS16 菌株中被鉴定出来。为了评估 libA 在环境中降解敌草隆的贡献，我们在农业土壤微宇宙和模拟农场生物净化系统基质的微宇宙中，监测了 libA 的丰度对敌草隆的应用和环境干扰的响应。通过实时 PCR 测量了 libA 的数量，并将其与报道的鞘氨醇单胞菌群落组成和敌草隆矿化能力的数据相关联。在土壤微宇宙和一个生物净化系统中，libA 的数量与敌草隆矿化能力的调节以及特定鞘氨醇单胞菌 phylotype（phylotype A）的出现相吻合，对敌草隆的应用和环境变化作出了响应。然而，在另一个生物净化系统中，没有发现这种相关性。我们的数据表明，在模拟的环境条件下，libA 的出现可以与敌草隆的矿化能力联系起来，并且 libA 主要由鞘氨醇单胞菌 phylotype A 菌株携带。然而，结果也表明，除了 libA 之外，其他尚未知的同工基因在环境中敌草隆矿化中也起着重要作用。
