Isolation, Characterization and Molecular Identification of Nitrogen Fixing Bacteria from Rhizosphere of Xylocarpus Moluccensis: Nitrogen-Fixing Bacteria from X. moluccensis

Fatiha Islam  Roshnee; Arifa Afrose  Rimi; Kumar Shubhro; Nazmul Rahman Chowdhury; Shaikh Mufrad Rahaman Anim; Kazi Mohammed Didarul Islam; Md. Emdadul Islam; S.M.Mahbubur Rahman; Anti Islam; Md. Morsaline Billah

doi:10.53808/KUS.2026.23.01.1457-ls

Authors

Fatiha Islam Roshnee Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
Arifa Afrose Rimi Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
Kumar Shubhro Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
Nazmul Rahman Chowdhury Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
Shaikh Mufrad Rahaman Anim Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
Kazi Mohammed Didarul Islam Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
Md. Emdadul Islam Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
S.M.Mahbubur Rahman Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh
Anti Islam Institute for Integrated Studies on the Sundarbans and Coastal Ecosystems (IISSCE), Khulna University, Khulna-9208, Bangladesh
Md. Morsaline Billah Biotechnology and Genetic Engineering Discipline, Khulna University, Khulna-9208, Bangladesh

DOI:

https://doi.org/10.53808/KUS.2026.23.01.1457-ls

Keywords:

Nitrogen fixation, Ammonification, IAA, Rhizosphere, Biochemical test, Pot test

Abstract

The research aimed to isolate, characterize, and molecularly identify nitrogen-fixing bacteria from the rhizosphere of Xylocarpus moluccensis, collected from the Sundarbans, Khulna, Bangladesh. This exploratory study focused on isolating bacteria capable of nitrogen fixation using Yeast Extract Mannitol Agar and Nitrogen-Free Burk’s Media. In addition, an ammonification test was performed to identify ammonia-producing bacteria for further evaluation. Through the isolation process, ten nitrogen-fixing bacterial strains were identified, all of which demonstrated the ability to produce indole-3-acetic acid (IAA), a key secondary metabolite involved in plant growth promotion. Biochemical tests were conducted to presumptively identify the bacterial isolates, with colony morphology suggesting the presence of Staphylococcus spp. and Kocuria spp. in the rhizosphere soil samples. To assess the plant growth-promoting potential of these isolates, a pot experiment was conducted using maize seedlings. The results indicated that bacterial inoculation substantially stimulated seedling growth and development, suggesting their potential as biofertilizers. However, further research is necessary to evaluate their impact on seed germination and crop yield before large-scale application in agricultural settings. Overall, this study highlights the presence of nitrogen-fixing bacteria in the rhizosphere of X. moluccensis, with promising implications for sustainable agriculture. The findings suggest that these bacterial strains could contribute to enhancing soil fertility and plant growth, supporting the development of eco-friendly biofertilizers.

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