Potential use of Pseudomonas koreensis AGB-1 in association with Miscanthus sinensis to remediate heavy metal(loid)-contaminated mining site soil

• Published in: Journal of environmental management 2015-03, Vol.151, p.160-166
• Main Authors: Babu, A. Giridhar, Shea, Patrick J., Sudhakar, D., Jung, Ik-Boo, Oh, Byung-Taek
• Format: Article
• Language: English
• Subjects: Bacteria; Biodegradation, Environmental; Biomass; Catalase; Chlorophylls; Data mining; Environmental management; Environmental Pollution - analysis; Flora; Heavy metal(loid)s; Heavy metals; Metals; Metals - analysis; Metals, Heavy - chemistry; Mine tailings; Mining; Miscanthus sinensis; Oxidative stress; Phytoremediation; Plant Development; Plant growth; Plant Roots - metabolism; Plants (organisms); Poaceae - metabolism; Pseudomonas; Pseudomonas - metabolism; Pseudomonas koreensis; Roots; Soil (material); Soil - chemistry; Soil Pollutants - chemistry; Soils; Transmission electron microscopy
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2014.12.045

Endophytic bacteria have the potential to promote plant growth and heavy metal(loid) (HM) removal from contaminated soil. Pseudomonas koreensis AGB-1, isolated from roots of Miscanthus sinensis growing in mine-tailing soil, exhibited high tolerance to HMs and plant growth promoting traits. Transmission electron microscope (TEM) analysis revealed that AGB-1 sequestered HMs extracellularly and their accumulation was visible as dark metal complexes on bacterial surfaces and outside of the cells. DNA sequencing of HM resistance marker genes indicated high homology to the appropriate regions of the arsB, ACR3(1), aoxB, and bmtA determinants. Inoculating mining site soil with AGB-1 increased M. sinensis biomass by 54%, chlorophyll by 27%, and protein content by 28%. High superoxide dismutase and catalase activities, and the lower malondialdehyde content of plants growing in AGB-1-inoculated soil indicate reduced oxidative stress. Metal(loid) concentrations in roots and shoots of plants grown in inoculated soil were higher than those of the controls in pot trials with mine tailing soil. Results suggest that AGB-1 can be used in association with M. sinensis to promote phytostabilization and remediation of HM-contaminated sites. •Pseudomonas koreensis AGB-1 inoculation increased heavy metal(loid) (HM) solubilization.•AGB-1 contains arsB, ACR3(1), aoxB and bmtA marker genes for HM resistance.•AGB-1 inoculation increased HM availability in the rhizosphere.•AGB-1 reduced HM stress, promoted Miscanthus sinensis growth, and increased HM uptake.•AGB-1-inoculated plants promoted phytostabilization and remediation of mine site soil.