Rice is a symbol of life and a representation of prosperity in South Korea. However, studies on the diversity of the bacterial communities in the rhizosphere of rice plants are limited. In this study, four bundles of root samples were collected from the same rice field located in Goyang, South Korea. These were systematically analyzed to discover the diversity of culturable bacterial communities through culture-dependent methods. A total of 504 culturable bacteria were isolated and evaluated for their plant growth-promoting abilities in vitro. Among them, Arthrobacter sp. GN70 was selected for inoculation into the rice plants under laboratory and greenhouse conditions. The results showed a significantly positive effect on shoot length, root length, fresh plant weight, and dry plant weight. Moreover, scanning electron microscopic (SEM) images demonstrated the accumulation of bacterial biofilm networks at the junction of the primary roots, confirming the root-colonizing ability of the bacterium. The strain also exhibited a broad spectrum of in vitro antimicrobial activities against bacteria and fungi. Here, we first report the rice plant growth-promoting ability of the Arthrobacter species with the biofilm-producing and antimicrobial activities against plant and human pathogens. Genome analyses revealed features attributable to enhance rice plant growth, including the genes involved in the synthesis of plant hormones, biofilm production, and secondary metabolites. This study revealed that the rhizobacteria isolated from the roots of rice plants have dual potential to be utilized as a plant growth promoter and antimicrobial agent.

In the present study, exopolysaccharide (EPS) produced by Lysobacter sp. MMG2 (lyEPS) was characterized and purified. The lyEPS-producing strain Lysobacter sp. MMG2 was isolated from the roots of Tagetes patula. When lyEPS was produced in tryptic soy broth with 1% glucose and the lyophilized powder was measured, the yield was found to be 0.67 g/L. The molecular weight (Mw) of lyEPS was 1.01 × 105 Da. Its monosaccharide composition includes 84.24% mannose, 9.73% glucose, 2.55% galactose, 2.77% arabinose, 0.32% xylose, and 0.03% rhamnose. Scanning electron microscopy (SEM) revealed that lyEPS has various round and rough surfaces. Fourier-transform infrared (FTIR) analysis identified its carbohydrate polymer functional groups. Moreover, thermogravimetric analysis of lyEPS revealed two events of mass loss: the first was water loss, which resulted in 3.97% mass loss and the second event occurred at approximately 212 °C. lyEPS could inhibit biofilm-producing pathogenic bacteria without any antimicrobial activity. Furthermore, lyEPS at a concentration of 4 mg/mL could exhibit potent 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity (89.25%). These results indicate that lyEPS could be a promising candidate for industrial development if its biological activity is further explored.

This study aims to elucidate the genomic characteristics of Bacillus subtilis MGE 2012, a strain isolated from Korean traditional fermented food, meju, which contributes to its high enzyme activity and potential applications. The whole genome sequence of B. subtilis MGE 2012 was assembled using MEGAHIT, annotated using RAST and BLASTKOALA v3.1. Phylogenetic analysis placed MGE 2012 within the Bacillus clade, showing high similarity to B. subtilis NCIB 3610 and B. subtilis ATCC 6051. AntiSMASH analysis identified 14 biosynthetic gene clusters (BGCs) capable of producing various secondary metabolites, including subtilosin, bacillibactin, fengycin, bacilysin, plipastatin, and surfactin. This study provides an overview of the whole genome and secondary metabolite profile of B. subtilis MGE 2012, emphasizing its potential applications in biotechnology. While the primary focus of this study was to explore the genomic characteristics and secondary metabolite profile, future research could delve deeper into genome mining for enzyme activities and their applications.

As the amount of power consumed by electronic products increases, a lot of studies focused on high capacity and miniaturization of batteries. In order to overcome the low capacity of carbon anode in Li rechargeable battery, researches on the development of high capacity anode material have been conducted. In particularly, it has been reported that pure lithium was adopted for high capacity of Li ion battery due to its light in weight and excellent theoretical capacity. However, when pure lithium is used, the capacity decreases rapidly as charging and discharging proceeded, which is reported to be formation of dendrite on the Li surface during charging/discharging. In order to suppress the growth of dendrite during charging/discharging, several researches have been focused on the Li impregnated metal foam for Li rechargeable battery. However, due to the poor wettability between metal foam and pure Li, adhesive materials had to be deposited by using expensive processes such as chemical vapor deposition to impregnate the Li into metal foam. In this study we focus on the heat treatment effect on the microstructure and Li-impregnation property of Ni metal foam. We oxidized the metal foam in a high temperature(500-900oC) for 5 min using the furnace to improve the wettability between the Lithium and Ni metal foam. Heat treated metal foam was dip into melted Li at 400 ^oC in a glove box. As a result, the rate of Li-impregnation in the heat treated metal foam was more than 10 times faster than that of the untreated Ni metal foam. The surface of heat treated Ni metal foam was characterized using transmission electron microscopy (TEM) equipped with energy dispersive X-ray spectroscopy(EDS). Figure. 1 shows the TEM image of the untreated and heat treated Ni metal foam surface. It reveals that an additional layer having a thickness of 200 nm was observed in the heat treated Ni foam. The additional layer was identified as polycrystalline NiOx by EDS and selected area diffraction pattern (SADP). It is believed that formation of NiOx was greatly contribute to improvement of the impregnation characteristics. In addition, the impregnation characteristics of Ni alloy foam will be discussed in this presentation. Figure 1