Moses Adondua Abah1,2, Micheal Abimbola Oladosu2,3, Okpanachi Nuhu Oyibo4, Adam Suleiman Ismail5, Brighotaye Cheery Vaekosen6, Clement Akutam Azure7, Soglohu Climesia Elikplim7, Peter Nnenna Happiness8, Chigozirim Steve Amadi9 and Chinedu Victoria Amarachi10
1Department of Biochemistry, Faculty of Biosciences, Federal University Wukari, Taraba State, Nigeria
2ResearchHub Nexus Institute, Nigeria
3Department of Chemical Sciences, Faculty of Science, Anchor University, Ayobo, Lagos State, Nigeria.
4Department of Biochemistry, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
5Department of Chemical Engineering, Faculty of Engineering and Engineering Technology, Abubakar Tafawa Balewa University Bauchi, Bauchi State, Nigeria
6Department of Chemical Engineering, Faculty of Engineering, University of Abuja, Abuja, Nigeria
7Department of Physical Science, Faculty of Liberal Arts and Science, Eastern New Mexico University, Portales, New Mexico, USA
8Department of Petroleum Engineering, Faculty of Engineering, University of Port Harcourt, Rivers State, Nigeria
9Department of Biochemistry, Faculty of Science, Rivers State University, Nkpolu- Oroworukwo, Port Harcourt, Rivers State, Nigeria
10Department of Microbiology, Federal University of Technology Owerri, Owerri, Imo State, Nigeria
Received: Mar 12, 2026/ Revised: Apr 8, 2026/Accepted: Apr 12, 2026
Corresponding Author: Moses Adondua Abah; m.abah@fuwukari.edu.ng
Abstract
The widespread contamination of soils by petroleum-derived compounds, particularly monoaromatic hydrocarbons such as toluene, presents significant environmental and public health challenges, especially in developing regions where automobile and industrial activities are prevalent. Mechanic workshops serve as major sources of such pollutants, underscoring the urgent need for effective and sustainable remediation strategies. This study aimed to isolate, identify, and characterize indigenous toluene-tolerant bacteria from soil samples collected at a mechanic site in Wukari, Taraba State, Nigeria, with the goal of evaluating their potential for bioremediation applications. Soil samples were obtained from various locations within the site and subjected to serial dilution, standard microbiological isolation procedures, and comprehensive morphological and biochemical characterization. Five bacterial species were identified: Pseudomonas hemolyticus, Bacillus subtilis, Pseudomonas aeruginosa, Bacillus cereus, and Rhodococcus ruber. The isolates displayed considerable morphological diversity, including variations in colony size, shape, color, and texture, as well as differences in motility and Gram reaction. Pseudomonas species were distinguished by their motility, smooth and moist pigmented colonies, and Gram-negative status, while Bacillus and Rhodococcus species were Gram-positive, with Rhodococcus ruber noted for its non-motile, reddish-orange colonies. Biochemical profiling revealed widespread catalase and citrate utilization among the isolates, indicative of their metabolic versatility and resilience in oxidative environments. Oxidase activity was prominent in Pseudomonas and Rhodococcus species, supporting their role in aerobic degradation of hydrocarbons. Glucose fermentation and indole production were observed primarily in the Bacillus species, suggesting adaptability to fluctuating oxygen levels and diverse nutrient conditions. These findings demonstrate that the soils of Wukari’s mechanic site harbor a metabolically and physiologically diverse bacterial community with substantial potential for the bioremediation of toluene-contaminated environments. The study reinforces the value of indigenous microorganisms as natural, effective agents for restoring polluted soils and highlights the importance of further research and field application to optimize their use in environmental clean-up initiatives in Nigeria and similar settings.
Keywords: Soil, Toluene, Bacteria, Tolerance, and Bioremediation
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How to cite this article
Adondua Abah, M., Abimbola Oladosu, M., Nuhu Oyibo, O., Suleiman Ismail, A., Cheery Vaekosen, B., Azure, C. A., Climesia Elikplim, S., Nnema Happiness, P., Steve Amadi, C., & Victoria Amarachi, C. (2026). Isolation, identification and characterisation of toluene-tolerant bacteria from soil samples obtained from New Site Mechanic, Wukari, Taraba State, for bioremediation application. Microbial Science Archives, 6(2), 17–24. https://doi.org/10.47587/MSA.2026.6201
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