Department of Microbiology and Virology, Medical University of Silesia, Jagiellońska 4, 41-200 Sosnowiec, Poland.
J Environ Manage. 2012 Oct 15;108:27-35. doi: 10.1016/j.jenvman.2012.05.002. Epub 2012 May 27.
We evaluated the response of soil bacteria to applications of the insecticide teflubenzuron at the field rate dosage (FR; 0.15 mg/kg of soil) and at a higher dosage (10FR; 1.5 mg/kg of soil). When applied at the FR dosage, teflubenzuron had no effect on several biochemical parameters of the soil, including substrate-induced respiration (SIR), dehydrogenase (DHA) and phosphatase activities (PHOS), and N-NO(3)(-) and N-NH(4)(+) concentrations. Additionally, no differences were observed in the culturable fraction of the soil bacteria (the number of heterotrophic, nitrifying, denitrifying and N(2)-fixing bacteria; the growth strategy; the ecophysiological and colony development indices; and the physiological state). In contrast, treatment with the 10FR dosage of the insecticide significantly increased SIR, DHA, PHOS and N-NH(4)(+) levels and the number of heterotrophic and denitrifying bacteria. Decreases in urease activity (URE) and the number of nitrifying and N(2)-fixing bacteria were also observed. A phospholipid fatty acid (PLFA) method-based analysis of the entire soil microorganism population revealed that teflubenzuron treatment affected the total fatty acid level as well as those considered to be of Gram-positive bacteria, Gram-negative bacteria and fungi. This effect was observed on days 1 and 14 post-treatment. A principal component analysis (PCA) of the PLFAs showed that teflubenzuron treatment significantly shifted the microbial community structure; however, all of the observed effects were transient. Studies on the degradation of teflubenzuron revealed that this process is characterised by a short lag phase and a rate constant (k) of 0.020/day. This degradation rate follows first-order kinetics, and the DT50 was 33.5 days. This is the first study that thoroughly examines the functional and structural status of both the culturable and non-culturable fractions of the soil microbial community after teflubenzuron application.
我们评估了杀虫剂氟铃脲在田间剂量（FR；0.15 毫克/千克土壤）和更高剂量（10FR；1.5 毫克/千克土壤）下对土壤细菌的反应。当以 FR 剂量施用时，氟铃脲对土壤的几种生化参数没有影响，包括基质诱导呼吸（SIR）、脱氢酶（DHA）和磷酸酶活性（PHOS）以及 N-NO3（-）和 N-NH4（+）浓度。此外，在土壤细菌的可培养部分（异养细菌、硝化细菌、反硝化细菌和固氮细菌的数量；生长策略；生态生理和菌落发育指数；以及生理状态）也没有观察到差异。相比之下，用杀虫剂 10FR 剂量处理显著增加了 SIR、DHA、PHOS 和 N-NH4（+）水平以及异养细菌和反硝化细菌的数量。脲酶活性（URE）和硝化细菌和固氮细菌的数量也有所减少。基于磷脂脂肪酸（PLFA）的整个土壤微生物种群分析表明，氟铃脲处理影响了总脂肪酸水平以及被认为是革兰氏阳性菌、革兰氏阴性菌和真菌的脂肪酸水平。这种影响在处理后第 1 天和第 14 天观察到。PLFA 的主成分分析（PCA）表明，氟铃脲处理显著改变了微生物群落结构；然而，所有观察到的影响都是暂时的。对氟铃脲降解的研究表明，该过程的特点是短的滞后期和 0.020/天的速率常数（k）。该降解速率遵循一级动力学，DT50 为 33.5 天。这是首次彻底研究氟铃脲应用后土壤微生物群落可培养和不可培养部分的功能和结构状态的研究。
