Seminar on the topic: Sustainable advances in biological methods and synthesis of nanomaterials by plasma jet

At 2:00 p.m. on December 4, 2025, IAST organized an seminar at the 5th floor meeting room of the Library (Tan Hung Campus) and Room 604, 99 Tran Quoc Toan (Hanoi Campus) with the following detailed content:

1/ Dr. Nguyen Thi Thanh Loan presented on the topic: Exploration of a multifunctional biocontrol agent Streptomyces sp. JCK-8055 for the management of apple fire blight
Abstract:

Apple fire blight, caused by the bacterium Erwinia amylovora, is a devastating disease of apple and pear trees. Biological control methods have attracted much attention from researchers to manage plant diseases as they are eco-friendly and viable alternatives to synthetic pesticides. Herein, we isolated Streptomyces sp. JCK-8055 from the root of pepper and investigated its mechanisms of action against E. amylovora. Streptomyces sp. JCK-8055 produces aureothricin and thiolutin, which antagonistically affects E. amylovora. JCK-8055 and its two active metabolites have a broad-spectrum in vitro activity against various phytopathogenic bacteria and fungi. They also effectively suppressed tomato bacterial wilt and apple fire blight in in vivo experiments. Specifically, JCK-8055 colonizes roots as a tomato seed coating and induces apple leaf shedding at the abscission zone, ultimately halting the growth of pathogenic bacteria. Additionally, JCK-8055 can produce the plant growth regulation hormone indole-3-acetic acid (IAA) and hydrolytic enzymes, including protease, gelatinase, and cellulase. JCK-8055 treatment also triggers the expression of salicylate (SA) and jasmonate (JA) signaling pathway marker genes, such as PR1, PR2, and PR3. Overall, our findings demonstrate that Streptomyces sp. JCK-8055 can control a wide range of plant diseases, particularly apple fire blight, through a combination of mechanisms such as antibiosis and induced resistance, highlighting its excellent potential as a biocontrol agent.

2/ MSc. Nguyen Thi Huyen presented on the topic: Synthesis of Cobalt Oxide Using a Plasma Jet Technique
Abstract:

In this study, nano-structured Co3O4 was successfully synthesized using a plasma jet treatment technique. This method provides a simple, efficient, and environmentally friendly route for material fabrication. Plasma was directly discharged into a precursor solution containing PEG, which served as both a reducing agent and a surfactant, promoting the formation of well-defined Co3O4 nanostructures while eliminating the need for hazardous chemical reductants. The structural and morphological properties of the prepared materials were featured using UV–Vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Furthermore, the electrochemical performance of the Co₃O₄ nanomaterials was evaluated to explore their potential for energy-storage applications. Overall, the results demonstrate that plasma jet processing is a promising and sustainable strategy for producing high-performance electrode materials suitable for next-generation energy-storage technologies..