Edith Hammer
Senior lecturer
Isolation and Identification of Insoluble Zinc-Solubilising Bacteria and Evaluation of Their Ability to Solubilise Various Zinc Minerals
Author
Summary, in English
Zinc (Zn) is an important trace element that is essential for optimal plant growth. Zinc-solubilising bacteria can release Zn from its insoluble compounds. We isolated and identified Zn-solubilising bacteria (ZnSB) from the rhizosphere, and semi-quantitively and quantitatively evaluated their ability to dissolve various Zn minerals (ZnO, ZnCO3 and Zn3(PO4)2). Out of 24 rhizosphere soil samples, 15 strains of Zn-solubilising bacteria were isolated and purified. Five isolates that were found to be the most efficient in solubilising insoluble Zn compounds were identified based on gene 16S rRNA sequencing. Three of the isolates belonged to the genus of Pseudomonas, and two to Enterobacter. The highest solubilisation index among the three insoluble Zn compounds was observed in Pseudomonas putida (3.31) in the culture medium containing ZnO. Among the three tested insoluble compounds, the highest mean solubility by the strains was obtained from ZnO, followed by ZnCO3, and Zn3(PO4)2, respectively. The highest rate of Zn release among the three insoluble compounds was obtained in the culture medium of the Pseudomonas fluorescence strain Ur22 (35.6 mg L−1), which was ten times as great as that of the background solubilisation observed in the sterile control culture medium (3.8 mg L−1). Zn solubilisation was associated with a strong pH decrease in the culture medium, the strongest for Pseudomonas fluorescence (Ur21), which lowered pH to 4.2 compared to the control at pH 6.8. We concluded that the identification of effective ZnSB, and their use as bio-fertiliser, will help improve plant nutrition and production.
Department/s
- Microbial Ecology
Publishing year
2021-09-01
Language
English
Pages
2501-2509
Publication/Series
Journal of Soil Science and Plant Nutrition
Volume
21
Issue
3
Document type
Journal article
Publisher
Sociedad Chilena de la Ciencia del Suelo
Topic
- Microbiology
Keywords
- 16S rRNA
- Rhizosphere
- Wheat
- Zinc-solubilizing bacteria
Status
Published
Research group
- Microbial Ecology
ISBN/ISSN/Other
- ISSN: 0718-9508