Objectives

In the current study, a new potential nanobiofungicide was investigated as hybrid composite antifungals; zinc oxide nanoparticles (ZNPs) in combination with microbial hydrolytic enzymes (Chitinases).

Methods

The Chitinase enzyme was achieved from a local isolate, which was identified as Bacillus licheniformis AG-W3. The enzyme production was achieved after 72 h of incubation at pH 7.5 and temperature 45 °C. The mean diameter of the synthesized nanoparticles (38-76 nm) was established by means of scanning electron microscope (SEM). Additionally, their antifungal activity was evaluated against Fusarium species.

Results

Based on the results obtained, ZNPs amended with Chitinase at 0.1% concentrations showed the strongest inhibitory effect (89.1%). A synergistic effect of Chitinase (0.03U/ml) in combination with ZNPs (0.005%) was observed up to 89.1%. The SEM results exhibits agglomerated spherical particles due to high surface energy. The average size calculated for calcined zinc nanoparticles are (38-76 nm) and this is in good agreement with the XRD results (equation (1): 46 nm).

Conclusions

It was concluded that the combination of ZNPs with Chitinase enzyme exhibits enhanced antifungal activity compared to their individual effects, considered a new alternative for synthetic fungicides. The development of novel nanocomposites for sustainable management of fungal diseases can mitigate the emergence of persistent and resilient fungal diseases and the crop losses that they cause. In addition, the importance of the current study was to establishing a consortium of chitinolytic microorganisms and nanoparticles appears to bring superior outcomes in fighting fungal phytopathogens, and also a potential alternative to these chemical pesticides, residing in soil and already the part of endophytic microbiome, have minimum altering effect on ecosystem.

中文翻译：

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评估对真菌病原镰刀菌具有抗菌潜力的纳米生物杀菌剂

目标

在当前的研究中，研究了一种新的潜在纳米生物杀菌剂作为混合复合抗真菌剂；氧化锌纳米粒子（ZNP）与微生物水解酶（几丁质酶）相结合。

方法

几丁质酶是从本地分离株中获得的，该分离株被鉴定为地衣芽孢杆菌AG-W3。在 pH 7.5 和温度 45 °C 下孵育 72 小时后即可产生酶。通过扫描电子显微镜（SEM）确定合成纳米颗粒的平均直径（38-76 nm）。此外，还针对镰刀菌属物种评估了它们的抗真菌活性。

结果

根据获得的结果，用0.1%浓度的几丁质酶修饰的ZNP显示出最强的抑制效果（89.1%）。观察到几丁质酶 (0.03U/ml) 与 ZNPs (0.005%) 组合的协同效应高达 89.1%。SEM 结果显示由于高表面能而形成团聚的球形颗粒。计算得到的煅烧锌纳米颗粒的平均尺寸为 (38-76 nm)，这与 XRD 结果非常吻合（方程(1)：46 nm）。

结论

结论是，ZNP 与几丁质酶的组合与其单独作用相比表现出增强的抗真菌活性，被认为是合成杀菌剂的新替代品。开发用于可持续管理真菌病害的新型纳米复合材料可以减轻持久性和弹性真菌病害的出现及其造成的作物损失。此外，当前研究的重要性在于建立几丁质分解微生物和纳米颗粒的联合体，似乎在对抗真菌植物病原体方面带来了优异的结果，并且也是这些化学农药的潜在替代品，存在于土壤中并且已经是内生微生物组的一部分，对生态系统的改变影响最小。