Alarcón Alejandro, Davies Fred T, Autenrieth Robin L, Zuberer David A
Department of Horticultural Sciences, Faculty of Molecular and Environmental Plant Sciences, Texas A&M University, College Station, Texas, USA.
Int J Phytoremediation. 2008 Jul-Aug;10:251-63. doi: 10.1080/15226510802096002.
While plants can phytoremediate soils that are contaminated with petroleum hydrocarbons, adding microbes to remediate contaminated sites with petroleum-degrading microorganisms and arbuscular mycorrhizal fungi (AMF) is not well understood. The phytoremediation of Arabian medium crude oil (ACO) was done with a Lolium multiflorum system inoculated with an AMF (Glomus intraradices) and a mixture of petroleum-degrading microorganisms--the bacterium, Sphingomonas paucimobilis (Sp) and the filamentous fungus, Cunninghamella echinulata (Ce, SpCe)--or with a combination of microorganisms (AMF + SpCe). Based on an earlier study on screening plants for phytoremediation of ACO, L. multiflorum (Italian ryegrass) was selected for its tolerance and rapid growth response (Alarcón, 2006). The plants were exposed to ACO-contaminated soil (6000 mg kg(-1)) for 80 d under greenhouse conditions. A modified Long Ashton Nutrient Solution (LANS) was supplied to all treatments at 30 microg P mL(-1), except for a second, higher P, control treatment at 44 microg P mL(-1). Inoculation with AMF, SpCe, or AMF + SpCe resulted in significantly increased leaf area as well as leaf and pseudostem dry mass as compared to controls at 30 microg P mL(-1). Populations of bacteria grown on a nitrogen-free medium and filamentous fungi increased with AMF + SpCe and SpCe treatments. The average total colonization and arbuscule formation of AMF-inoculated plants in ACO-contaminated soil were 25% and 8%, respectively. No adverse effects were caused by SpCe on AMF colonization. Most importantly, ACO degradation was significantly enhanced by the addition of petroleum-degrading microorganisms and higher fertility controls, as compared to plants at 30 microg P mL(-1). The highest ACO degradation (59%) was observed with AMF + SpCe. The phytoremediation of ACO was also enhanced by single inoculation of AMF or SpCe. The effect of AMF and petroleum-degrading microorganisms on plant growth and ACOdegradation was not attributable to differences in proline, total phenolics, nitrate reductase levels, or variation in plant-gas exchange.
虽然植物可以对受石油烃污染的土壤进行植物修复，但利用石油降解微生物和丛枝菌根真菌（AMF）添加微生物来修复受污染场地的情况尚未得到充分了解。采用多花黑麦草系统，接种AMF（根内球囊霉）和石油降解微生物混合物——细菌少动鞘氨醇单胞菌（Sp）和丝状真菌刺孢小克银汉霉（Ce，SpCe），或采用微生物组合（AMF + SpCe）对阿拉伯中质原油（ACO）进行植物修复。基于早期关于筛选用于ACO植物修复的植物的研究，选择多花黑麦草（意大利黑麦草）是因其耐受性和快速生长反应（阿拉孔，2006年）。在温室条件下，将植物暴露于受ACO污染的土壤（6000毫克/千克）中80天。除了第二个较高磷含量的对照处理为44微克磷/毫升外，所有处理均以30微克磷/毫升的量供应改良的长阿什顿营养液（LANS）。与30微克磷/毫升的对照相比，接种AMF、SpCe或AMF + SpCe导致叶面积以及叶和假茎干质量显著增加。在无氮培养基上生长的细菌和丝状真菌种群在AMF + SpCe和SpCe处理下增加。在受ACO污染的土壤中，接种AMF的植物的平均总定殖率和丛枝形成率分别为25%和8%。SpCe对AMF定殖没有造成不利影响。最重要的是，与30微克磷/毫升的植物相比，添加石油降解微生物和较高肥力对照显著增强了ACO的降解。观察到AMF + SpCe的ACO降解率最高（59%）。单独接种AMF或SpCe也增强了ACO的植物修复。AMF和石油降解微生物对植物生长和ACO降解的影响并非归因于脯氨酸、总酚、硝酸还原酶水平的差异或植物气体交换的变化。
