Nitrogen-fixing and IAA-producing bacterial strains isolated from maize soil in Vietnamese mountainous regions
Year: 2025
Type: article
Abstract: Nitrogen (N) is the most limiting factor for crop yield, especially in acidic soils. A biological approach should be taken as the usage of chemical N fertilizer is expensive and harmful to both human health and the environment. Therefore, the current study aimed at isolating a promising N2-fixing bacteria (NFB) that can provide IAA as an indicator of a plant growth promoter. The origin of isolation was in the mountainous areas in the North of Vietnam. The finest isolate according to IAA and N-fixing. Then, the biochemical and genomic traits of the selected isolate were determined. Eight of the twelve NFB strains identified in the study were able to produce IAA. The IAA-producing NFB showed an amount of 18.882–109.381 NH4+ and 4.321–22.158 IAA (µg/ml). The NL1 strain was chosen because of its exceptional performance compared to the other strains. The morphology and biochemical processes of the NL1 strain were determined. Its growth condition was as follows: duration (A) of 5.22 days, temperature (B) of 31.73°C, and pH (C) of 6.61 at the maximum bacteria density of 3.12159 × 108 CFU/ml. After that, the NL1 strain was identified as Azospirillum sp. and contained 12 N2-fixing genes and 4 IAA-producing genes. This indicates the potential of the Azospirillum sp. NL1 strain as a N2 fixer and an IAA producer. Thus, to increase soil fertility and crop productivity, and partially replace chemical fertilizer for sustainable agriculture, it should be further investigated in greenhouse and field studies.
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDGs: Zero hunger, Life on land
Open Access status: diamond
OpenAlex ID: W7124464443