Isolation and Bioassay of N-fixing Bacteria from Mercury-Contaminated Tailing and Soil of Artisanal and Small-Scale Gold Mining.

Item request has been placed! ×
Item request cannot be made. ×
loading   Processing Request
Read More Add to Saved list
  • Additional Information
    • Subject Terms:
      PLANT growth-promoting rhizobacteria; FOXTAIL millet; INDOLEACETIC acid; GOLD mining; NITROGEN-fixing bacteria
    • Abstract:
      This study aims to isolate Nitrogen-fixing bacteria from tailing and heavy metal (HM) polluted soils and examine their effectiveness as a plant growth-promoting rhizobacteria (PGPR) to increase foxtail millet plant growth. We analyzed artisanal and small-scale gold mining (ASGM) sites in Pongkor Village, West Java, Indonesia, and identified nine areas with significant contamination of Mercury (Hg), Lead (Pb), Cadmium (Cd), Chromium (Cr), and Arsenic (As). We isolated sixteen strains of nitrogen-fixing bacteria different carbon sources. We identified three strains (3.2.h, 4.2.b, and 9.2.a) that the most robust nitrogenase activity and indole acetic acid (IAA) production. They were identified based on their molecular characteristics (16S rRNA) as Ralstonia pickettii strain LMQOTU12, Azotobacter chroococcum subsp. isscasi strain P205, and Azotobacter chroococcum subsp. isscasi strain P205. The three isolates were inoculated to foxtail millet plant grown under Andosol slightly acidic (pH 5.8), moderate nitrogen content (0.26%). The three strains isolates demonstrated significant enhancement to foxtail millet plants' growth. Improvements (compared to control) in shoot dry weight: 8% (3.2.h), 32% (4.2.b), 88% (9.2.a); longest root length: 88.71% (3.2.h), 108.90% (4.2.b), 140.16%; root dry weight: 350% (3.2.h), 450% (4.2.b), 250% (9.2.a); and root-shoot ratio 312% (3.2.h), 312% (4.2.b), 75% (9.2.a). This study demonstrates that the three strains are potential PGPRs for increasing plant growth of foxtail millet. [ABSTRACT FROM AUTHOR]
    • Abstract:
      Copyright of Geomicrobiology Journal is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)