Application of Arthrobacter sp. YM27 for Promoting Germination and Early Growth of Panicum in Heavy Metal-Contaminated Soil; [중금속 오염 토양에서 기장의 발아 및 초기 생장 향상을 위한Arthrobacter sp. YM27 활용]

Abstract

Contaminated soil with heavy metals like cadmium (Cd) severely inhibits plant growth. In this study, we isolated 34 strains of metal-resistant bacteria with plant growth-promoting characteristics from soil around a smelter. Among them, Arthrobacter sp. YM27 was selected for its excellent activities, including indole-3-acetic acid production, exopolysaccharide production, and catalase activity. The YM27 strain exhibited over 72% antifungal activity against the pathogenic fungus Botrytis cinerea and could grow at Cd concentrations up to 50 μM, with a half-maximal effective concentration (EC50) of 4.38 ± 0.50 µM. When inoculated into Cd-contaminated soil (216.40 ± 4.10 ppm), the effects of YM27 on panicum (Panicum miliaceum L.) germination and growth were examined. Under YM27 inoculation, the germination rate increased by 1.3 times, and chlorophyll content increased by 1.09 times compared to the control. The lengths of the panicum shoot and root were 1.5 and 1.6 times greater, respectively (p < 0.05), with fresh weights increasing 1.67 times and 2 times (p < 0.05). The germination index of panicum under Cd contamination reached 440%, and the vigor index improved 2.2 times compared to the control. This study confirms that the inoculation of Cd-resistant Arthrobacter sp. YM27 can enhance panicum germination and biomass in metal-contaminated soils, suggesting its potential as a valuable resource for improving phytoremediation efficiency. © 2024, The Korean Society for Microbiology and Biotechnology.