The contamination of the environment has been a global issue, and bioremediation is proposed as an option to clean up the contamination sites with the promising utilization of bacterial community capabilities. The indigenous bacterial community in the landfill leachate is recognized to carry enzymes for the degradation of contaminants such as dioxin congeners, the dibenzofuran. Environmental factors have been known to influence the process to achieve successful biodegradation, and the optimized conditions may speed up the biodegradation process. Thus, this study was conducted to optimize the substrate availability, temperature, and pH factor for the degradation of dibenzofuran from landfill leachate by the native bacterial community in landfill leachate. This study uses the one-factor at-time (OFAT) approach to measure dibenzofuran degradation. The landfill leachate with enrichment of dibenzofuran (15 to 45 mg L-1) was incubated at temperatures (30°C to 42°C) and pH (5 to 9) for 24 hours before being extracted and analyzed. From the first part of the study, 15 mg L-1 of dibenzofuran, 30°C temperature, and pH 7 have shown the highest dibenzofuran degradation. Later, the optimum condition of dibenzofuran removal (74.40%) was achieved when the landfill leachate was spiked with 15 ppm dibenzofuran at 30°C and pH 7 for 24 hours. This study proposes optimized conditions that give a better result for dibenzofuran degradation, which may enhance bioremediation.

• Al-Hawash, A. B., Dragh, M. A., Li, S., Alhujaily, A., Abbood, H. A., Zhang, X., & Ma, F. (2018). Principles of microbial degradation of petroleum hydrocarbons in the environment. Egyptian Journal of Aquatic Research, 44(2), 71-76. https://doi.org/10.1016/j.ejar.2018.06.001

• Ambust, S., Das, A. J., & Kumar, R. (2021). Bioremediation of petroleum contaminated soil through biosurfactant and Pseudomonas sp. SA3 amended design treatments. Current Research in Microbial Sciences, 2, Article 100031. https://doi.org/10.1016/j.crmicr.2021.100031

• Arliyani, I., Tangahu, B. V., & Mangkoedihardjo, S. (2021). Selection of plants for constructed wetlands based on climate and area in the interest of processing pollutant parameters on leachate: A review. IOP Conference Series: Earth and Environmental Science, 835(1), Article 012003. https://doi.org/10.1088/1755-1315/835/1/012003

• Aziz, S. Q., Bashir, M. J. K., Aziz, H. A., Mojiri, A., Salem, S., Amr, A., & Maulood, Y. I. (2018). Statistical analysis of municipal solid waste landfill leachate characteristics in different countries. Zanco Journal of Pure and Applied Sciences, 30(6), 85-96. https://doi.org/10.21271/zjpas.30.6.8

• Baran, A., Mierzwa-Hersztek, M., Urbaniak, M., Gondek, K., Tarnawski, M., Szara, M., & Zieliński, M. (2020). An assessment of the concentrations of PCDDs/Fs in contaminated bottom sediments and their sources and ecological risk. Journal of Soils and Sediments, 20, 2588-2597. https://doi.org/10.1007/s11368-019-02492-3

• Baran, A., Urbaniak, M., Szara, M., & Tarnawski, M. (2021). Concentration of dioxin and screening level ecotoxicity of pore water from bottom sediments in relation to organic carbon contents. Ecotoxicology, 30, 57-66. https://doi.org/10.1007/s10646-020-02318-w

• Dávalos-Peña, I., Fuentes-Rivas, R. M., Fonseca-Montes de Oca, R. M. G., Ramos-Leal, J. A., Morán-Ramírez, J., & Martínez Alva, G. (2021). Assessment of physicochemical groundwater quality and hydrogeochemical processes in an area near a municipal landfill site: A case study of the toluca valley. International Journal of Environmental Research and Public Health, 18(21), Article 11195. https://doi.org/10.3390/ijerph182111195

• Earnden, L., Marangoni, A. G., Laredo, T., Stobbs, J., Marshall, T., & Pensini, E. (2022). Decontamination of water co-polluted by copper, toluene and tetrahydrofuran using lauric acid. Scientific Reports, 12(1), 1-20. https://doi.org/10.1038/s41598-022-20241-4

• Eldos, H. I., Zouari, N., Saeed, S., & Al-Ghouti, M. A. (2022). Recent advances in the treatment of PAHs in the environment: Application of nanomaterial-based technologies. Arabian Journal of Chemistry, 15, Article 103918. https://doi.org/10.1016/j.arabjc.2022.103918

• Eskenazi, B., Warner, M., Brambilla, P., Signorini, S., Ames, J., & Mocarelli, P. (2018). The Seveso accident: A look at 40 years of health research and beyond. Environment International, 121, 71-84. https://doi.org/10.1016/j.envint.2018.08.051

• Ferronato, N., & Toretta, V. (2019). Waste mismanagement in developing countries: A review of global issues. International Journal of Environmental Research and Public Health, 16(1060), 1-28. https://doi.org/10.3390/ijerph16061060

• Gaur, N., Dutta, D., Singh, A., Dubey, R., & Kamboj, D. V. (2022). Recent advances in the elimination of persistent organic pollutants by photocatalysis. Frontiers in Environmental Science, 10, Article 872514. https://doi.org/10.3389/fenvs.2022.872514

• Haedrich, J., Stumpf, C., & Denison, M. S. (2020). Rapid extraction of total lipids and lipophilic POPs from all EU regulated foods of animal origin: Smedes ’ method revisited and enhanced. Environmental Sciences Europe, 32(118), 1-33. https://doi.org/10.1186/s12302-020-00396-5

• Imron, M. F., Kurniawan, S. B., Ismail, N. I., & Abdullah, S. R. S. (2020). Future challenges in diesel biodegradation by bacteria isolates: A review. Journal of Cleaner Production, 251, Article 119716. https://doi.org/10.1016/j.jclepro.2019.119716

• Kumari, P., Kaur, A., & Gupta, N. C. (2018). Extent of groundwater contamination due to leachate migration adjacent to unlined landfill site of Delhi. Environmental Claims Journal, 31(2), 160-175. https://doi.org/10.1080/10406026.2018.1543825

• Mahjoubi, M., Aliyu, H., Neifar, M., Cappello, S., Chouchane, H., Souissi, Y., Masmoudi, A. S., Cowan, D. A., & Cherif, A. (2021). Genomic characterization of a polyvalent hydrocarbonoclastic bacterium Pseudomonas sp. strain BUN14. Scientific Reports, 11, 1-13. https://doi.org/10.1038/s41598-021-87487-2

• Maier, R. M., & Pepper, I. L. (2015). Chapter 3 - Bacterial growth. In I. L. Pepper, C. P. Gerba & T. J. Gentry (Eds.), Environmental Microbiology (Third Edition) (pp. 37-56). Academic Press. https://doi.org/10.1016/B978-0-12-394626-3.00003-X

• Morris, S., Garcia-Cabellos, G., Enright, D., Ryan, D., & Enright, A. M. (2018). Bioremediation of landfill leachate using isolated bacterial strains. International Journal of Environmental Bioremediation & Biodegradation, 6(1), 26-35. https://doi.org/10.12691/ijebb-6-1-4

• Nhung, N. T. H., Nguyen, X. T. T., Long, V. D., Wei, Y., & Fujita, T. (2022). A Review of soil contaminated with dioxins and biodegradation technologies: Current status and future prospects. Toxics, 10(6), Article 278. https://doi.org/10.3390/toxics10060278

• Njoku, P. O., Edokpayi, J. N., & Odiyo, J. O. (2019). Health and environmental risks of residents living close to a landfill: A case study of thohoyandou landfill, Limpopo Province, South Africa. International Journal of Environmental Research and Public Health, 16(2125), 1-27. https://doi.org/10.3390/ijerph16122125

• Rashwan, T. L., Fournie, T., Green, M., Duchesne, A. L., Brown, J. K., Grant, G. P., Torero, J. L., & Gerhard, J. I. (2022). Applied smouldering for co-waste management: Benefits and trade-offs. Fuel Processing Technology, 240, Article 107542. https://doi.org/10.1016/j.fuproc.2022.107542

• Razali, Y. S., Tajarudin, H. A., & Daud, Z. (2018). Extraction of volatile fatty acids from leachate via liquid-liquid extraction and adsorption method. International Journal of Integrated Engineering, 10(9), 79-84. https://doi.org/10.30880/ijie.2018.10.09.029

• Saibu, S., Adebusoye, S. A., & Oyetibo, G. O. (2020). Aerobic bacterial transformation and biodegradation of dioxins: A review. Bioresources and Bioprocessing, 7(7), 1-21. https://doi.org/10.1186/s40643-020-0294-0

• Salam, M., & Nilza, N. (2021). Hazardous components of landfill leachates and its bioremediation. In M. L. Larramendy & S. Soloneski (Eds.), Soil Contamination-Threats and Sustainable Solutions (pp. 167-176). IntechOpen.

• Sani, M. S. A., Bakar, J., Azid, A., & Iqbal, M. J. (2022). Chemometrics-based evaluation on the effect of sonication, contact time and solid-to-solvent ratio on total phenolics and flavonoids, free fatty acids and antibacterial potency of Carica papaya seed against S. enteritidis, B. cereus, V. vulnificus and P. mirabilis. Food Chemistry Advances, 1, Article 100033. https://doi.org/10.1016/j.focha.2022.100033

• Sanusi, N. H. (2017). Degradation Analysis of Dibenzofuran by Rhizospheric Bacteria. Kulliyyah of Science, International Islamic Universiti Malaysia.

• Soare, M. G., Lakatos, E. S., Ene, N., Malo, N., Popa, O., & Babeanu, N. (2019). The potential applications of bacillus sp. And pseudomonas sp. strains with antimicrobial activity against phytopathogens in waste oils and the bioremediation of hydrocarbons. Catalysts, 9(11), Article 959. https://doi.org/10.3390/catal9110959

• Szajner, J., Czarby-Działak, M., Żeber-Dzikowska, I., Dziechciaż, M., Pawlas, N., & Walosik, A. (2021). Dioxin-like compounds (DLCs) in the environment and their impact on human health. Journal of Elementology, 26(2), 419-431. https://doi.org/10.5601/jelem.2021.26.2.2130

• Tajudin, M. T. F. M. (2017). Microbial Degradation of Polychlorinated Biphenyls and Dibenzofuran by Burkholderia xenovurans LB400 Isolated from Landfill Leacahete. Kulliyyah of Science, International Islamic University Malaysia.

• Tarekegn, M. M., Salilih, F. Z., & Ishetu, A. I. (2020). Microbes used as a tool for bioremediation of heavy metal from the environment. Cogent Food and Agriculture, 6(1), Article 1783174. https://doi.org/10.1080/23311932.2020.1783174

• Tas, N., Brandt, B. W., Braster, M., Van, B. M., & Wilfred, F. M. R. (2018). Subsurface landfill leachate contamination affects microbial metabolic potential and gene expression in the Banisveld aquifer. FEMS Microbiology Ecology, 94(10), 1-12. https://doi.org/10.1093/femsec/fiy156

• Terzaghi, E., Vergani, L., Mapelli, F., Borin, S., Raspa, G., Zanardini, E., Morosini, C., Anelli, S., Nastasio, P., Sale, V. M., Armiraglio, S., & Di Guardo, A. (2020). New data set of polychlorinated dibenzo-p-dioxin and dibenzofuran half-lives: Natural attenuation and rhizoremediation using several common plant species in a weathered contaminated soil. Environmental Science and Technology, 54(16), 10000-10011. https://doi.org/10.1021/acs.est.0c01857

• Vidonish, J. E., Zygourakis, K., Masiello, C. A., Sabadell, G., & Alvarez, P. J. J. (2016). Thermal treatment of hydrocarbon-impacted soils: A review of technology innovation for sustainable remediation. Engineering, 2(4), 426-437. https://doi.org/10.1016/J.ENG.2016.04.005

• Wdowczyk, A., & Szymańska-Pulikowska, A. (2021). Comparison of landfill leachate properties by LPI and phytotoxicity - A case study. Frontiers in Environmental Science, 9, 1-14. https://doi.org/10.3389/fenvs.2021.693112

• Xiang, W., Wei, X., Tang, H., Li, L., & Huang, R. (2020). Complete genome sequence and biodegradation characteristics of benzoic acid-degrading bacterium Pseudomonas sp. SCB32. BioMed Research International, 2020, 1-12. https://doi.org/10.1155/2020/6146104

• Zakaria, S. N. F., & Aziz, H. A. (2018). Characteristic of leachate at Alor Pongsu landfill site, Perak, Malaysia: A comparative study. In IOP Conference Series: Earth and Environmental Science (Vol. 140, No. 1, p. 012013). IOP Publishing.

• Zhao, L., Zhou, M., Zhao, Y., Yang, J., Pu, Q., Yang, H., Wu, Y., Lyu, C., & Li, Y. (2022). Potential toxicity risk assessment and priority control strategy for PAHs metabolism and transformation behaviors in the environment. International Journal of Environmental Research and Public Health, 19(17), 1-25. https://doi.org/10.3390/ijerph191710972

• Zhao, R., Liu, J., Feng, J., Li, X., & Li, B. (2021). Microbial community composition and metabolic functions in landfill leachate from different landfills of China. Science of the Total Environment, 767, Article 144861. https://doi.org/10.1016/j.scitotenv.2020.144861