title: Characterizations of purple non-sulfur bacteria isolated from paddy fields, and identification of strains with potential for plant growth-promotion, greenhouse gas mitigation and heavy metal bioremediation.
abstract: This study was aimed at selecting purple non-sulfur bacteria (PNSB) isolated from various paddy fields, including Cd- and Zn-contaminated paddy fields, based on their biofertilizer properties. Among 235 PNSB isolates, strain TN110 was most effective in plant growth-promoting substance (PGPS) production, releasing 3.2 mg/L of [Formula: see text] , 4.11 mg/L of 5-aminolevulinic acid (ALA) and 3.62 mg/L of indole-3-acetic acid (IAA), and reducing methane emission up to 80%. This strain had nifH, vnfG and anfG, which are the Mo, V and Fe nitrogenase genes encoded for key enzymes in nitrogen fixation under different conditions. This strain provided 84% and 55% removal of Cd and Zn, respectively. Another isolate, TN414, not only produced PGPS (1.30 mg/L of [Formula: see text] , 0.94 mg/L of ALA and 0.65 mg/L of IAA), but was also efficient in removing both Cd and Zn at 72% and 74%, respectively. Based on 16S rDNA sequencing, strain TN110 was identified as Rhodopseudomonas palustris, while strain TN414 was Rubrivivax gelatinosus. A combination of TN110 and TN414 could potentially provide a biofertilizer, which is a greener alternative to commercial/chemical fertilizers and an agent for bioremediation of heavy metals and greenhouse gas mitigation in paddy fields.
authors.affiliation: Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand. Electronic address: jakkapan.js5@gmail.com.
authors.forename: Jakkapan
authors.initials: J
authors.lastname: Sakpirom
authors.affiliation: Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand. Electronic address: duangporn.k@psu.ac.th.
authors.forename: Duangporn
authors.initials: D
authors.lastname: Kantachote
authors.affiliation: Faculty of Medicine, Princess of Naradhiwas University, Narathiwat, Thailand. Electronic address: tomorn.n@gmail.com.
authors.forename: Tomorn
authors.initials: T
authors.lastname: Nunkaew
authors.affiliation: Department of Civil and Environmental Engineering, North Dakota State University, Fargo, ND 58108, USA. Electronic address: eakalak.khan@ndsu.edu.
authors.forename: Eakalak
authors.initials: E
authors.lastname: Khan
mesh_terms: D000383:Agriculture; D000622:Aminolevulinic Acid / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism*; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000235:genetics; D012275:Oryza; D063245:Plant Development; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012241:Rhodopseudomonas / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis; D015032:Zinc / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D019216:Metals, Heavy; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D002104:Cadmium; C030737:indoleacetic acid; D000622:Aminolevulinic Acid; D009591:Nitrogenase; D015032:Zinc
keywords: 5-Aminolevulinic acid; Cadmium; Indole-3-acetic acid; Nitrogenase genes; Purple non-sulfur bacteria; Zinc