One-pot synthesis of metal nanoparticles under ambient temperature and pressure using reducing and stabilizing materials from microbes is energy-effective and ecofriendly, but upstream extraction of biological raw materials and downstream purification of nanoparticles from bioreactors are laborious and expensive. To simplify the productive process for using metal nanoparticles as microbicides to control plant pathogens, we use an endospore-forming Bacillus biocontrol agent to produce the nano-microbicide and use the bacterial raw materials as bio-microbicides together with the nano-microbicide.Bacillus cells at the stationary phase form endospores and tolerate Ag+ and Ag nanoparticles (AgNPs), while the cell-free culture supernatant (CFCS) mediates the synthesis of AgNPs. AgNPs produced from the Bacillus culture and CFCS show similar physical, chemical, and electrical characteristics, and bactericidal and anti-biofilm activities. Moreover, the diluted products effectively protect the kiwifruit leaves from the infection of the pathogen Pseudomonas syringae pv. actinidiae.This coproduction of bio-microbicide and nano-microbicide is a totally green one-pot synthesis process without extraction and purification and without production of waste and can be easily scaled up using the existing fermentation processing of Bacillus biocontrol agents. The application of the synergistic bio-microbicide and nano-microbicide can effectively control the bacterial canker disease of kiwifruit plants.
Nanocarrier-based controlled-release technologies significantly enhance the effective utilization rate of pesticides. Multimodal synergistic antimicrobial strategies that disrupt multiple pesticide resistance pathways are considered promising for plant disease management. In this study, a novel pH-responsive pesticide delivery system based on kasugamycin-intercalated Zn Fe hydrotalcites (KAS-Zn-Fe HTlc) was developed to achieve synergistic antibacterial effects. KAS-Zn-Fe HTlc was synthesized via a co-precipitation method. Its physicochemical properties were characterized using SEM, XRD, UV–vis, and FT-IR. The loading capacity, controlled release kinetics, thermal stability, photostability, antibacterial activity, and crop safety were evaluated. KAS-Zn-Fe HTlc exhibited rapid release of KAS and Zn 2+ under acidic conditions. KAS-Zn-Fe HTlc enhanced the thermal stability of KAS and significantly reduced its photodegradation during the initial phase. Bioactivity assays demonstrated that KAS-Zn-Fe HTlc exhibited 32-fold and 2-fold increased antibacterial activity against Clavibacter michiganensis subsp. michiganensis and Pseudomonas syringae pv. lachrymans , respectively, when compared to KAS. No phytotoxicity was observed in tomato seedlings treated with KAS-Zn-Fe HTlc. Therefore, KAS-Zn-Fe HTlc holds significant potential for synergistic antimicrobial functions and offers a sustainable approach to plant disease control.
危险品化学品经营许可证（带存储）