Thünen Institute of Biodiversity, Federal Research Institute for Rural Areas, Forestry and Fisheries, Bundesallee 50, Braunschweig, Germany.
ISME J. 2014 Jun;8(6):1289-300. doi: 10.1038/ismej.2013.233. Epub 2014 Jan 16.
Many organic pollutants are readily degradable by microorganisms in soil, but the importance of soil organic matter for their transformation by specific microbial taxa is unknown. In this study, sorption and microbial degradation of phenol and 2,4-dichlorophenol (DCP) were characterized in three soil variants, generated by different long-term fertilization regimes. Compared with a non-fertilized control (NIL), a mineral-fertilized NPK variant showed 19% and a farmyard manure treated FYM variant 46% more soil organic carbon (SOC). Phenol sorption declined with overall increasing SOC because of altered affinities to the clay fraction (soil particles <2 mm in diameter). In contrast, DCP sorption correlated positively with particulate soil organic matter (present in the soil particle fractions of 63-2000 μm). Stable isotope probing identified Rhodococcus, Arthrobacter (both Actinobacteria) and Cryptococcus (Basidiomycota) as the main degraders of phenol. Rhodococcus and Cryptococcus were not affected by SOC, but the participation of Arthrobacter declined in NPK and even more in FYM. (14)C-DCP was hardly metabolized in the NIL variant, more efficiently in FYM and most in NPK. In NPK, Burkholderia was the main degrader and in FYM Variovorax. This study demonstrates a strong effect of SOC on the partitioning of organic pollutants to soil particle size fractions and indicates the profound consequences that this process could have for the diversity of bacteria involved in their degradation.
许多有机污染物很容易被土壤中的微生物降解，但土壤有机质对特定微生物类群转化它们的重要性尚不清楚。在这项研究中，通过三种不同长期施肥制度产生的土壤变体，研究了苯酚和 2,4-二氯苯酚（DCP）的吸附和微生物降解。与未施肥对照（NIL）相比，矿物肥料 NPK 变体的土壤有机碳（SOC）增加了 19%，而厩肥处理的 FYM 变体则增加了 46%。由于对粘土部分（直径<2 毫米的土壤颗粒）的亲和力发生变化，苯酚的吸附随着总 SOC 的增加而下降。相比之下，DCP 的吸附与颗粒状土壤有机质呈正相关（存在于 63-2000 微米的土壤颗粒部分中）。稳定同位素探测确定了节杆菌属（放线菌）、节杆菌属（放线菌）和隐球菌属（担子菌）是苯酚的主要降解菌。节杆菌属和隐球菌属不受 SOC 影响，但 Arthrobacter 的参与在 NPK 中减少，在 FYM 中甚至更多。14C-DCP 在 NIL 变体中几乎不被代谢，在 FYM 中更有效，在 NPK 中最有效。在 NPK 中，伯克霍尔德菌是主要的降解菌，在 FYM 中是沃氏菌。本研究表明 SOC 对有机污染物分配到土壤颗粒大小分数有很强的影响，并表明这一过程对参与其降解的细菌多样性可能产生深远的影响。
