Gramss G, Voigt K D, Kirsche B
Project Development Centre, Erfurt, Germany.
Biodegradation. 1999 Feb;10(1):51-62. doi: 10.1023/a:1008368923383.
Seven commercial 3- to 7-ring (R) polycyclic aromatic hydrocarbons (PAH) as well as PAH derived from lignite tar were spiked into 3 soils (0.8 to 9.7% of organic carbon). The disappearance of the original PAH was determined for the freshly spiked soils, for soils incubated for up to 287 d with their indigenous microflora, and for autoclaved, unsterile and pasteurized soils inoculated with basidiomycetous and ascomycetous fungi. Three to 12 d after spiking, 22 to 38% of the PAH could no longer be recovered from the soils. At 287 d, 88.5 to 92.7%, 83.4 to 87.4%, and 22.0 to 42.1% of the 3-, 4-, and 5- to 7-R PAH, respectively, had disappeared from the unsterile, uninoculated soils. In 2 organic-rich sterile soils, the groups of wood- and straw-degrading, terricolous, and ectomycorrhizal fungi reduced the concentration of 5 PAH by 12.6, 37.9, and 9.4% in 287 d. Five- to 7-R PAH were degraded as efficiently as most of the 3- to 4-R PAH. In organic-rich unsterile soils inoculated with wood- and straw-degrading fungi, the degradation of 3- to 4-R PAH was not accelerated by the presence of fungi. The 5- to 7-R PAH, which were not attacked by bacteria, were degraded by fungi to 29 to 42% in optimum combinations of fungal species and soil type. In organic-poor unsterile soil, these same fungi delayed the net degradation of PAH possibly for 2 reasons. Mycelia of Pleurotus killed most of the indigenous soil bacteria expected to take part in the degradation of PAH, whereas those of Hypholoma and Stropharia promoted the development of opportunistic bacteria in the soil, which must not necessarily be PAH degraders. Contemporarily, the contribution of the fungi themselves to PAH degradation may be negligible in the absence of soil organic matter due to the lower production of ligninolytic enzymes. It is concluded that fungi degrade PAH irrespective of their molecular size in organic-rich and wood chip-amended soils which promote fungal oxidative enzyme production.
将七种市售的3至7环（R）多环芳烃（PAH）以及源自褐煤焦油的PAH添加到3种土壤中（有机碳含量为0.8%至9.7%）。测定了新添加PAH的土壤、与本地微生物群落一起培养长达287天的土壤以及接种担子菌和子囊菌的高压灭菌、未灭菌和巴氏灭菌土壤中原始PAH的消失情况。添加后3至12天，22%至38%的PAH无法再从土壤中回收。在287天时，未灭菌、未接种的土壤中，3环、4环以及5至7环PAH分别有88.5%至92.7%、83.4%至87.4%和22.0%至42.1%消失。在2种富含有机质的无菌土壤中，木材和秸秆降解真菌、土生真菌以及外生菌根真菌在287天内使5种PAH的浓度分别降低了12.6%、37.9%和9.4%。5至7环PAH的降解效率与大多数3至4环PAH相同。在接种了木材和秸秆降解真菌的富含有机质未灭菌土壤中，真菌的存在并未加速3至4环PAH的降解。未受细菌攻击的5至7环PAH，在真菌种类和土壤类型的最佳组合下，被真菌降解了29%至42%。在贫有机质未灭菌土壤中，这些真菌可能由于两个原因延迟了PAH的净降解。平菇的菌丝体杀死了大多数预期参与PAH降解的本地土壤细菌，而丝盖伞属和球盖菇属的菌丝体促进了土壤中机会主义细菌的生长，这些细菌不一定是PAH降解菌。同时，由于木质素分解酶产量较低，在缺乏土壤有机质的情况下，真菌自身对PAH降解的贡献可能微不足道。得出的结论是，在促进真菌氧化酶产生的富含有机质和添加木片的土壤中，真菌能够降解PAH，而不论其分子大小。
