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Efficient Removal of Paraquat by Rhizobium sp. Strain HRI101-4: A Combined Affirmation Through In Vitro and In Silico Studies

by Jui Biswas 1 Shirmin Islam 1 Suvro Biswas 1 Md. Ariful Islam 1 Mohammad Abdullah Taher 2 Pranab Karmaker 2 Md. Salah Uddin 1 Shahriar Zaman 1 Md. Abu Saleh 1*

  1. 1 Microbiology Laboratory, Department of Genetic Engineering and Biotechnology, University of Rajshahi, Bangladesh
  2. 2 Bangladesh Reference Institute for Chemical Measurements (BRiCM), Bangladesh

* Author to whom correspondence should be addressed. Md. Abu Saleh ()

Integrative Bioscience Nexus 2026 , 1(1) , https://doi.org/10.xxxx/ibn.2026.11.0005 —

Received May 2, 2026 Revised June 12, 2026 Accepted June 15, 2026 Published July 5, 2026

Abstract

Soil microorganisms can respond to herbicides after exposure, with certain bacteria capable of breaking them down and using the energy for growth. Herbicides like paraquat (C12H14Cl2N2), which inhibit plant photosynthesis, pose significant environmental and health risks. In this study, an herbicide-degrading Rhizobacterium was isolated from agricultural soil treated with paraquat. The strain was identified through morphological and molecular techniques, and its growth was optimized at 35℃ over 72 hours, with pH levels of 7 and 7.5. Spectrophotometric and HPLC analyses revealed 99% paraquat degradation, reducing the concentration to 8.82 µg/ml, with optimal degradation occurring at pH 4 and 30℃. The strain also demonstrated tolerance to certain heavy metals and resistance to various antibiotics. 16S rRNA sequencing confirmed a 98% similarity to Rhizobium sp. strain HRI101-4, emphasizing its potential in mitigating paraquat pollution. Molecular docking analysis was conducted to explore the binding interactions between five enzymes from Rhizobium sp. The binding affinities, indicated by docking scores, ranged from -7.3 for dehydrogenase to -5.2 for malate dehydrogenase. The analysis showed that enzymes from Rhizobium sp. interact with paraquat in distinct manners, suggesting a variety of binding affinities and interaction sites. This indicates that these enzymes may influence paraquat’s functions, potentially affecting its degradation activity.

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Cite this article

Jui Biswas, Shirmin Islam, Suvro Biswas, Md. Ariful Islam, Mohammad Abdullah Taher, Pranab Karmaker, Md. Salah Uddin, Shahriar Zaman, & Md. Abu Saleh (2026). Efficient Removal of Paraquat by Rhizobium sp. Strain HRI101-4: A Combined Affirmation Through In Vitro and In Silico Studies. Integrative Bioscience Nexus, 1(1). https://doi.org/10.xxxx/ibn.2026.11.0005