Biofilms Benefiting Plants Exposed to ZnO and CuO Nanoparticles Studied with a Root-Mimetic Hollow Fiber Membrane
Biofilms Benefiting Plants Exposed to ZnO and CuO Nanoparticles Studied with a Root-Mimetic Hollow Fiber Membrane
复制标题
DOI：
10.1021/acs.jafc.7b02524
复制
发表时间：
2018-07-04
影响因子：
6.1
通讯作者：
Britt, David W.
中科院分区：
文献类型：
--
作者：
Bonebrake, Michelle;Anderson, Kaitlyn;Britt, David W.
植物与一群影响植物健康的微生物共存，包括对生物和非生物胁迫的反应。随着纳米颗粒(NP)与植物相互作用的研究越来越多，纳米颗粒对植物微生物群落的影响研究较少。在这里，提出了一种模拟根的中空纤维膜(HFM)，用于产生人工根分泌物(Ares)培养的植物相关微生物的生物膜，以将渗出液成分与生物膜的形成和对NPs的响应联系起来。从大田小麦中分离到两株微生物，一株内生芽孢杆菌和一株假单胞菌根表面定殖菌，在供给不同氮、碳组成的ARES的HFMS上进行研究。用扫描电子显微镜和原子力显微镜对细菌的形态和生物膜结构进行了表征，并评估了细菌对CuO和ZnO NP 300 mg/L挑战的响应。芽孢杆菌分离物稀疏地定植在HFM上。相比之下，假单胞菌在3天内形成了强大的生物膜。依赖于营养源，生物膜细胞产生广泛的胞外聚合物(EPS)和大的胞内颗粒。纳米氧化锌对假单胞菌生物膜的影响最小。当在生物膜成熟之前引入CuO纳米颗粒时，会显著减少生物膜的形成。结果表明，HFM根模拟物可用于研究根分泌物对根部定植微生物生物膜的影响，但没有活跃的植物代谢。这一结果将有助于更好地了解微生物-根际渗出物NP相互作用如何影响微生物和植物健康。
Plants exist with a consortium of microbes that influence plant health, including responses to biotic and abiotic stress. While nanoparticle (NP) plant interactions are increasingly studied, the effect of NPs on the plant microbiome is less researched. Here a root-mimetic hollow fiber membrane (HFM) is presented for generating biofilms of plant-associated microbes nurtured by artificial root exudates (AREs) to correlate exudate composition with biofilm formation and response to NPs. Two microbial isolates from field-grown wheat, a bacillus endophyte and a pseudomonad root surface colonizer, were examined on HFMs fed with AREs varying in N and C composition. Bacterial morphology and biofilm architecture were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM) and responses to CuO and ZnO NP challenges of 300 mg/L evaluated. The bacillus isolate sparsely colonized the HFM. In contrast, the pseudomonad formed robust biofilms within 3 days. Dependent on nutrient sources, the biofilm cells produced extensive extracellular polymeric substances (EPS) and large intracellular granules. Pseudomonad biofilms were minimally affected by ZnO NPs. CuO NPs, when introduced before biofilm maturation, strongly reduced biofilm formation. The findings demonstrate the utility of the HFM root-mimetic to study rhizoexudate influence on biofilms of root-colonizing microbes but without active plant metabolism. The results will allow better understanding of how microbe-rhizoexudate NP interactions affect microbial and plant health.