Investigation of the sqr and fcc Genes Associated with the Sulfur Oxidation Activity of a Rhodobacter capsulatus Strain Isolated in Vietnam
Main Article Content
Abstract
Flavoproteins sulfide:quinone oxidoreductase (SQR) and flavocytochrome c sulfide dehydrogenase (FCC), two key enzymes involved in the sulfide oxidation pathways, are responsible for the hydrogen sulfide (H2S)-metabolizing capability of various bacterial strains employed in the biological treatments of the toxic gas H2S. Previous studies mainly focus on the isolation of sulfur-oxidizing bacteria (SOB) and the evaluation of the total sulfur oxidation activity. Thus, in this study, an in-depth investigation of the sqr, fcc genes, the encoded proteins, and their association with the sulfide oxidation activity in a SOB bacterial strain, Rhodobacter capsulatus, was carried out. Firstly, the specific primers were designed and used to amplify sqr and fcc genes of a Rhodobacter capsulatus strain isolated in Vietnam. In addition, the bacterial cells were fractionated to obtain periplasmic, membrane, and cytoplasmic fractions for denaturing SDS-PAGE analysis and activity assay. On the SDS-PAGE gel, the bands corresponding to the calculated molecular weights of SQR (approximately 47 kDa in the membrane fraction) and FCC (approximately 35 kDa in the periplasmic fraction) could be observed. Significantsulfide oxidation activity could be detected in the periplasmic and the membrane fractions compared to the cytoplasmic fraction (2 and 20 times higher, respectively). More importantly, sulfide oxidation activities in these fractions were inhibited by the specific flavoproteininhibitor KCN, indicating possible association of SQR and FCC with the recorded activity. The study has initially established the evidence supporting the link between the presence of sqr, fcc-encoded proteins and the sulfide oxidation activity in the studied R. capsulatusbacterial strain for further research utilizing SOB in environmental treatment applications.
References
[2] Ferrera I., R. Massana, E. Casamayor, V. Balagué, O. Sánchez, C. Pedrós-Alió, and J. Mas (2004), “High-diversity biofilm for the oxidation of sulfide-containing effluents”, Applied microbiology and biotechnology, 64, pp. 726-734.
[3] Zhao X., X. Li, N. Qi, Z. Fu, M. Chen, B. Jiang, and X. Hu (2018), “Enhancement of COD, ammonia, phosphate and sulfide simultaneous removal by the anaerobic photosynthetic bacterium of Ectothiorhodospira magna in batch and sequencing batch culture”, Water Sci Technol, 78 (9), pp. 1852-1860.
[4] Griesbeck C., G. Hauska, and M. Schütz (2000), “Biological Sulfide Oxidation: Sulfide-Quinone Reductase (SQR), the Primary Reaction”, Recent Research Developments in Microbiology, Vol. 4.
[5] Osipov E.M., A.V. Lilina, S.I. Tsallagov, T.N. Safonova, D.Y. Sorokin, T.V. Tikhonova, and V.O. Popov (2018), “Structure of the flavocytochrome c sulfide dehydrogenase associated with the copper-binding protein CopC from the haloalkaliphilic sulfur-oxidizing bacterium Thioalkalivibrio paradoxusARh 1”, Acta Crystallogr D Struct Biol, 74 (Pt 7), pp. 632-642.
[6] Đỗ Thị Liên N.T.D.P., Nguyễn Thị Biên Thùy, Đỗ Thị Tố Uyên, Đinh Duy Khang (2014), “Ảnh hưởng của chế phẩm vi khuẩn tía quang hợp đến chất lượng môi trường ao nuôi cá rô phi thâm canh.”, Tạp chí Khoa học và Phát triển, tập 12 (3), pp. 379-383.
[7] D. B.Minh, P.T. Ha. Isolation and Selection of Purple Non-Sulfur Bacteria for Nutrient Rich Biomass Production from Wastes, VNU Journal of Science: Natural Sciences and Technology 37(2021) 24-34,https://doi.org/10.25073/2588-1140/vnunst.5121.
[8] M .G. Klotz, S. W. Hutcheson. Multiple periplasmic catalases in phytopathogenic strains of Pseudomonas syringae, Applied and Environmental Microbiology 58 (1992), 2468-2473; https://doi.org/10.1128/aem.58.8.2468-2473.1992.
[9] Kruger, N.J. (2009). The Bradford Method For Protein Quantitation. In: Walker, J.M. (eds) The Protein Protocols Handbook. Springer Protocols Handbooks. Humana Press, Totowa, NJ. https://doi.org/10.1007/978-1-59745-198-7_4.
[10] Horwitz, J., & Wong, M. M. (1980). Peptide mapping by limited proteolysis in sodium dodecyl sulfate of the main intrinsic polypeptides isolated from human and bovine lens plasma membranes. Biochimica et biophysica acta, 622(1), 134–143. https://doi.org/10.1016/0005-2795(80)90165-8
[11] T. Hirano, H. Kurosawa, K. Nakamura and Y. Amano, Simultaneous removal of hydrogen sulphide and
trimethylamine by a bacterial deodorant. Journal of Fermentation and Bioengineering 81 (1996), 337-342.
https://doi.org/10.1016/0922-338X(96)80587-3.
[12] A. Kolmert, P. Wikström. P, K. B. Hallberg, A fast and simple turbidimetric method for the determination of sulfate in sulfate-reducing bacterial cultures, Journal of Microbiological Methods 41 (2000), 179-184, https://doi.org/10.1016/S0167-7012(00)00154-8.
[13] Carruthers, N. J., Parker, G. C., Gratsch, T., Caruso, J. A., & Stemmer, P. M. (2015). Protein Mobility Shifts Contribute to Gel Electrophoresis Liquid Chromatography Analysis. Journal of biomolecular techniques : JBT, 26(3), 103–112. https://doi.org/10.7171/jbt.15-2603-003.
[14] Ozimek, P., Veenhuis, M., & van der Klei, I. J. (2005). Alcohol oxidase: a complex peroxisomal, oligomeric flavoprotein. FEMS yeast research, 5(11), 975–983. https://doi.org/10.1016/j.femsyr.2005.06.005.
[15] Brito, J. A., Sousa, F. L., Stelter, M., Bandeiras, T. M., Vonrhein, C., Teixeira, M., Pereira, M. M., & Archer, M. (2009). Structural and functional insights into sulfide:quinone oxidoreductase. Biochemistry, 48(24), 5613–5622. https://doi.org/10.1021/bi9003827.
[16] Visser, J. M., de Jong GAH, Robertson, L. A., & Kuenen, J. G. (1997). A novel membrane-bound flavocytochrome c sulfide dehydrogenase from the colourless sulfur bacterium Thiobacillus sp. W5. Archives of microbiology, 167(5), 295–301. https://doi.org/10.1007/s002030050447,