Arsenic-tolerant plant-growth-promoting bacteria isolated from arsenic-polluted soils in South Korea

• Published in: Environmental science and pollution research international 2014, Vol.21 (15), p.9356-9365
• Main Authors: Shagol, Charlotte C, Krishnamoorthy, Ramasamy, Kim, Kiyoon, Sundaram, Subbiah, Sa, Tongmin
• Format: Article
• Language: English
• Subjects: 1-aminocyclopropane-1-carboxylate deaminase; Acetic acid; Agriculture; Aquatic Pollution; Arsenic; Arsenic - chemistry; Arsenic - metabolism; Arsenic - toxicity; Arsenite; arsenites; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Bacteria - drug effects; Bacteria - genetics; Bacteria - metabolism; Biodegradation, Environmental; Bioremediation; Brevibacterium; Carboxylic acids; corn; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Genera; Genetic diversity; Heavy metal content; Heavy metals; indole acetic acid; Indoleacetic acid; metal tolerance; Metals; Metals, Heavy - chemistry; Metals, Heavy - metabolism; Metals, Heavy - toxicity; Microbacterium; Microorganisms; Minimum inhibitory concentration; nitrogen; oxidation; Paenibacillus; Phytoremediation; Plant Development; Plant growth; plant growth-promoting rhizobacteria; polluted soils; pollution; Pseudomonas; Rahnella; Reduction; Republic of Korea; Research Article; Rhodococcus; Rhodococcus aetherovorans; siderophores; Smelters; Sodium arsenite; Soil - chemistry; Soil contamination; Soil Microbiology; Soil microorganisms; Soil Pollutants - chemistry; Soil Pollutants - metabolism; Soil Pollutants - toxicity; Soil pollution; Soil remediation; Soil testing; Soils; solubilization; species diversity; Studies; Waste Water Technology; Water Management; Water Pollution Control; Zea mays
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-014-2852-5

The Janghang smelter in Chungnam, South Korea started in 1936 was subsequently shutdown in 1989 due to heavy metal (loid) pollution concerns in the vicinity. Thus, there is a need for the soil in the area to be remediated to make it usable again especially for agricultural purposes. The present study was conducted to exploit the potential of arsenic (As)-tolerant bacteria thriving in the vicinity of the smelter-polluted soils to enhance phytoremediation of hazardous As. We studied the genetic and taxonomic diversity of 21 As-tolerant bacteria isolated from soils nearer to and away from the smelter. These isolates belonging to the genera Brevibacterium, Pseudomonas, Microbacterium, Rhodococcus, Rahnella, and Paenibacillus, could tolerate high concentrations of arsenite (As(III)) and arsenate (As(V)) with the minimum inhibitory concentration ranging from 3 to >20 mM for NaAsO₂ and 140 to 310 mM NaH₂AsO₄ · 7H₂O, respectively. All isolates exhibited As(V) reduction except Pseudomonas koreensis JS123, which exhibited both oxidation and reduction of As. Moreover, all the 21 isolates produced indole acetic acid (IAA), 13 isolates exhibited 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, 12 produced siderophore, 17 solubilized phosphate, and 13 were putative nitrogen fixers under in vitro conditions. Particularly, Rhodococcus aetherivorans JS2210, P. koreensis JS2214, and Pseudomonas sp. JS238 consistently increased root length of maize in the presence of 100 and 200 μM As(V). Possible utilization of these As-tolerant plant-growth-promoting bacteria can be a potential strategy in increasing the efficiency of phytoremediation in As-polluted soils.