Abstract：
Bacteria and fungi are the most important soil organisms owing to their abundance and the key roles they play in the functioning of ecosystems. We examined possible synergistic and antagonistic effects during the degradation of polycyclic aromatic hydrocarbons (PAHs) by co-cultures of ascomycetes and a plant-growth-promoting bacterium.
Bacteria and fungi were grown in a liquid nutrient medium supplemented with PAHs. The PAH degradations and the identification of metabolites were checked by high-performance liquid chromatography (HPLC). Enzymatic activities were measured spectrophotometrically using test substrates. All experimental treatments were analyzed using Excel 2019 (Microsoft Office 2019, USA).
The model system included the plant-growth-promoting rhizobacterium (PGPR) Azospirillum brasilense and one of the following ascomycetes: Fusarium oxysporum (plant pathogen), Talaromyces sayulitensis (rhizospheric fungus), Trichoderma viride (plant-growth-promoting fungus, PGPF), and Trichoderma harzianum (PGPF). The notable results are: (1) synergistic effects consisted of more active utilization of the PAH mixture compared to individual compounds, while the PAH mixture was more actively degraded by co-cultures than monocultures; (2) three effects of mutual influence by the studied organisms were also revealed: depressing (F. oxysporum and A. brasilense), partially depressing (T. sayulitensis suppressed the growth of A. brasilense but increased the degradation of anthracene, pyrene, and fluoranthene), and positive effects (A. brasilense and T. viride or T. harzianum); (3) for the first time quinone metabolites of PAH degradation and extracellular oxidase and peroxidase were produced during PAH degradation by T. sayulitensis.Conclusions: The results of the study contribute to the understanding of bacterial-fungal interactions in polluted settings.
Bacteria and fungi were grown in a liquid nutrient medium supplemented with PAHs. The PAH degradations and the identification of metabolites were checked by high-performance liquid chromatography (HPLC). Enzymatic activities were measured spectrophotometrically using test substrates. All experimental treatments were analyzed using Excel 2019 (Microsoft Office 2019, USA).
The model system included the plant-growth-promoting rhizobacterium (PGPR) Azospirillum brasilense and one of the following ascomycetes: Fusarium oxysporum (plant pathogen), Talaromyces sayulitensis (rhizospheric fungus), Trichoderma viride (plant-growth-promoting fungus, PGPF), and Trichoderma harzianum (PGPF). The notable results are: (1) synergistic effects consisted of more active utilization of the PAH mixture compared to individual compounds, while the PAH mixture was more actively degraded by co-cultures than monocultures; (2) three effects of mutual influence by the studied organisms were also revealed: depressing (F. oxysporum and A. brasilense), partially depressing (T. sayulitensis suppressed the growth of A. brasilense but increased the degradation of anthracene, pyrene, and fluoranthene), and positive effects (A. brasilense and T. viride or T. harzianum); (3) for the first time quinone metabolites of PAH degradation and extracellular oxidase and peroxidase were produced during PAH degradation by T. sayulitensis.Conclusions: The results of the study contribute to the understanding of bacterial-fungal interactions in polluted settings.
摘要：
背景：细菌和真菌是最重要的土壤生物，因为它们的丰度以及它们在生态系统功能中的关键作用。我们通过子囊菌和植物生长促进细菌的共培养研究了多环芳烃（PAHs）降解过程中可能的协同和拮抗作用。
方法：在补充有PAHs的液体营养培养基中培养细菌和真菌。通过高效液相色谱（HPLC）检查PAH降解和代谢物的鉴定。使用测试底物通过分光光度法测量酶活性。所有实验治疗均使用Excel2019（MicrosoftOffice2019，USA）进行分析。
结果：模型系统包括促进植物生长的根际细菌（PGPR）巴西拟螺旋体和以下子囊菌之一：尖孢镰刀菌（植物病原体），sayulitensis(根际真菌)，绿色木霉（促进植物生长的真菌，PGPF)，和哈茨木霉（PGPF）。显著的结果是：（1）协同作用包括更积极地利用PAH混合物相比于单个化合物，而PAH混合物通过共培养比单一培养更活跃地降解；（2）还揭示了所研究生物相互影响的三种影响：抑制（F.尖孢和A.brasilense)，部分压抑(T.sayulitensis抑制了A的生长。巴西，但增加了蒽的降解，芘,和荧蒽)，和积极影响(A.Brasilense和T.viride或T.harzianum）；（3）在PAH降解过程中首次产生PAH降解的醌代谢产物以及细胞外氧化酶和过氧化物酶。结论：研究结果有助于了解污染环境中的细菌-真菌相互作用。
方法：在补充有PAHs的液体营养培养基中培养细菌和真菌。通过高效液相色谱（HPLC）检查PAH降解和代谢物的鉴定。使用测试底物通过分光光度法测量酶活性。所有实验治疗均使用Excel2019（MicrosoftOffice2019，USA）进行分析。
结果：模型系统包括促进植物生长的根际细菌（PGPR）巴西拟螺旋体和以下子囊菌之一：尖孢镰刀菌（植物病原体），sayulitensis(根际真菌)，绿色木霉（促进植物生长的真菌，PGPF)，和哈茨木霉（PGPF）。显著的结果是：（1）协同作用包括更积极地利用PAH混合物相比于单个化合物，而PAH混合物通过共培养比单一培养更活跃地降解；（2）还揭示了所研究生物相互影响的三种影响：抑制（F.尖孢和A.brasilense)，部分压抑(T.sayulitensis抑制了A的生长。巴西，但增加了蒽的降解，芘,和荧蒽)，和积极影响(A.Brasilense和T.viride或T.harzianum）；（3）在PAH降解过程中首次产生PAH降解的醌代谢产物以及细胞外氧化酶和过氧化物酶。结论：研究结果有助于了解污染环境中的细菌-真菌相互作用。
