Biodegradation of isoproturon in agricultural soils with contrasting pH by exogenous soil microbial communities
Biodegradation of isoproturon in agricultural soils with contrasting pH by exogenous soil microbial communities
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DOI：
10.1016/j.soilbio.2016.08.022
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发表时间：
2016-12-01
影响因子：
9.7
通讯作者：
Munch, Jean Charles
中科院分区：
文献类型：
--
作者：
Li, Renyi;Doerfler, Ulrike;Munch, Jean Charles
土壤pH值是异丙隆（伊普）田间生物降解的限制因素。伊普耗散是阻碍在低pH值的土壤中。伊普耗散的两个IPU矿化微生物群落的功效进行了研究，在189天的缩影三个农业土壤与对比pH值（Marsdorf，pH值3.8;诺伊马尔克，pH值5.8和Durneck，pH值7.3）。分别从酸性土壤（MC-AS）和中性土壤（MC-NS）富集的微生物群落建立在载体材料，即膨胀粘土颗粒上，并引入到测试土壤中，载体-土壤比为1%。在第0天和第133天，将伊普施用于土壤两次。研究了接种量、吸附-解吸和pH对伊普生物降解的影响。用均匀环标记的[C-14]-异丙隆分析伊普矿化、可提取残留物和不可提取残留物。这两种微生物群落导致显着增强伊普矿化（52%-60%）和低浓度的伊普残留物在土壤Durneck（pH 7.3）。获得的IPU矿化活性在土壤中至少持续133 d。最初，在土壤诺伊马尔克（pH 5.8）中，通过PANMC-AS获得了9倍高的伊普矿化率。然而，没有处理和未处理的土壤之间的差异，检测后伊普重新应用。这两个社区伊普的命运在土壤Marsdorf（pH 3.8），伊普的生物降解受到抑制，约2%的伊普矿化超过189天的影响可以忽略不计。降低载体-土壤比为0.1%急剧降低的IPU矿化能力的MC-AS在土壤诺伊马尔克，然而，这种效果的接种量是不太明显的两个微生物群落在土壤Durneck。伊普的Kd值较低（1.3-2.0 mL g（-1）），表明伊普的生物有效性不是伊普在土壤中降解的限制因素。MC-AS和MC-NS在土壤中的pH值与伊普最大矿化量之间的关系与在无机盐介质中观察到的关系非常接近，表明pH值是影响外源微生物群落对伊普生物降解的重要因素。我们建议，MC-AS，它具有广泛的pH值的伊普降解的容忍度，是一个很有前途的候选人加速伊普消散在酸性土壤中。接种密度对伊普降解的影响具有土壤微生物群落特异性。根据目标土壤的生理要求和性质使用降解微生物可以最大限度地提高伊普消散的有效性。(C)2016爱思唯尔有限公司版权所有
Soil pH is a limiting factor for biodegradation of isoproturon (IPU) in the field. IPU dissipation is hampered in soil with low pH. Efficacy of two IPU-mineralizing microbial communities in IPU dissipation was investigated during 189 d in microcosms of three agricultural soils with contrasting pH (Marsdorf, pH 3.8; Neumarkt, pH 5.8 and Durneck, pH 7.3). The microbial communities enriched from an acidic soil (MC-AS) and a neutral soil (MC-NS), respectively, were established on carrier material, namely expanded clay particles, and introduced to the tested soils at a carrier-soil ratio of 1%. IPU was applied to the soil twice, on day 0 and day 133. The effect of inoculation size, sorption desorption and pH on biodegradation of IPU were studied. IPU mineralization, extractable residues and non-extractable residues were analyzed with uniformly ring-labeled [C-14]-isoproturon. Both microbial communities resulted in significantly enhanced IPU mineralization (52%-60%) and low concentrations of IPU residues in soil Durneck (pH 7.3). The acquired IPU-mineralizing activity was persistent in the soil for at least 133 d. Initially a 9-fold higher IPU mineralization rate was attained in soil Neumarkt (pH 5.8) by inoculating MC-AS. However, no difference between treated and untreated soils was detected after IPU reapplication. Both communities had negligible effect on the fate of IPU in soil Marsdorf (pH 3.8), where biodegradation of IPU was inhibited, with approximate to 2% IPU mineralized over 189 d. Lowering the carrier-soil ratio to 0.1% sharply reduced the IPU-mineralizing capacity of MC-AS in soil Neumarkt, however, this effect of inoculation size was less pronounced for both microbial communities in soil Durneck. The low Kd of IPU (1.3-2.0 mL g(-1)) indicate that IPU bioavailability is not a limiting factor of IPU degradation in the soils. Relationships between pH and maximal IPU mineralization rendered by MC-AS or MC-NS in soil closely approximate those observed in mineral salts medium, suggesting that pH is an important factor influencing biodegradation of IPU by the exogenous microbial communities. We propose that MC-AS, which has a broad pH tolerance for IPU degradation, is a promising candidate for accelerating IPU dissipation in acidic soils. The effect of inoculant density on IPU degradation is microbial community-soil specific. Using degrader microorganisms according to their physiological requirements and properties of the targeted soils may maximize the effectiveness of IPU dissipation. (C) 2016 Elsevier Ltd. All rights reserved.