Bioenergetic Aspects of Dibenzothiophene Desulfurization by Growing Cells of Ralstonia eutropha

Document Type : Original Research Paper

Authors

1 Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran

2 Department of Chemical Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran

Abstract

The present study focuses on effects of initial pH on dibenzothiophene (DBT) desulfurization via 4S pathway by growing cells of Ralstonia eutropha. For so doing, temporal changes of biomass concentration, glucose as a sole carbon source, pH value, and 2-hydroxybiphenyl (2-HBP) formation have been monitored during the bioprocess. The biomass concentration has been modeled by the logistic equation and results show that the values of maximum specific growth rate (μmax) and maximum cell concentration (Xmax) have increased in line with the rise of initial pH from 6 to 9. This confirms the effect of pH on the energetics of cell growth via altering the proton gradient and manipulating ATP-related metabolic pathways. By considering the Pirt’s maintenance concept, the bioenergetic aspects of DBT desulfurization process are affected by changes in pH, where the maximum specific DBT conversion rate (0.0014 mmol/gcell.h) has been obtained at initial pH of 8. Additionally, the kinetic modeling of the 2-HBP formation through the Luedeking-Piret model indicates that the DBT desulfurization rate is linearly related to the cell growth rate, instead of biomass concentration. The growth associated and non-growth associated 2-HBP formation constants have been obtained 3.82 mg2-HBP/gcell and 0.06 mg2-HBP/gcell.h, respectively at an initial pH of 8.

Keywords


Boltes, K., del Aguila, R. A. and García-Calvo, E. (2013). Effect of mass transfer on biodesulfurization kinetics of alkylated forms of dibenzothiophene by Pseudomonas putida CECT5279. J. Chem. Technol. Biotechnol., 88(3); 422-431.
Boniek, D., Figueiredo, D., dos Santos, A. F. B. and de Resende Stoianoff, M. A. (2015). Biodesulfurization: a mini review about the immediate search for the future technology. Clean Technol. Environ. Policy, 17(1); 29-37.
Initial pH
α (mg2-HBP/gcell)
β (mg2-HBP/gcell.h)
Sy.x
Value
t-test
Value
t-test
6
3.37 ± 0.45
23.61
0.04 ± 0.03
3.89
0.20
7
3.53 ± 0.58
19.36
0
˗
0.33
8
3.82 ± 0.57
21.79
0.06 ± 0.04
4.57
0.33
9
2.80 ± 0.27
33.03
0.08 ± 0.02
11.33
0.17
Dejaloud, A., et al.
718
Caro, A., Boltes, K., Leton, P. and Garcia-Calvo, E. (2008). Description of by-product inhibition effects on biodesulfurization of dibenzothiophene in biphasic media. Biodegradation, 19(4); 599-611.
Carvajal, P., Dinamarca, M. A., Baeza, P., Camu, E. and Ojeda, J. (2017). Removal of sulfur-containing organic molecules adsorbed on inorganic supports by Rhodococcus Rhodochrous spp. Biotechnol. Lett., 39; 241-245.
Chen, H., Zhang, W.J., Cai, Y. B., Zhang, Y. and Li, W. (2008). Elucidation of 2-hydroxybiphenyl effect on dibenzothiophene desulfurization by Microbacterium sp. strain ZD-M2. Bioresour. Technol., 99(15); 6928-6933.
Debabov, V. G. (2010). Microbial desulfurization of motor fuel. Appl. Biochem. Microbiol., 46; 733-738.
Dejaloud, A., Vahabzadeh, F. and Habibi, A. (2017). Ralstonia eutropha as a biocatalyst for desulfurization of dibenzothiophene. Bioprocess. Biosyst. Eng., 40(7); 969-980.
del Olmo, C. H., Santos, V. E., Alcon, A. and Garcia-Ochoa, F. (2005). Production of a Rhodococcus erythropolis IGTS8 biocatalyst for DBT biodesulfurization: influence of operational conditions. Biochem. Eng. J., 22(3); 229-237.
Doelle, H. W., Ewings, K. N. and Hollywood, N. W. (1981). Regulation of glucose metabolism in bacterial systems. Adv. Biochem. Eng./Biotechnol., 23; 1-36.
Kilbane, J. J. and Stark, B. (2016). Biodesulfurization: a model system for microbial physiology research. World J. Microbiol. Biotechnol., 32(8); 137.
Kim, Y. J., Chang, J. H., Cho, K. S., Ryu, H. W. and Chang, Y. K. (2004). A physiological study on growth and dibenzothiophene (DBT) desulfurization characteristics of Gordonia sp. CYKS1. Korean J. Chem. Eng., 21(2); 436-441.
Lapin, L. L. (1997). Modern Engineering Statistics. (Belmont, CA: Duxbury Press)
Luedeking, R. and Piret, E. L. (1959). A Kinetic study of the lactic acid fermentation. Batch process at controlled pH. J. Biochem. Microbiol. Technol. Eng., 1(4); 393-412.
Martin, A. B., Alcon, A., Santos, V. E. and Garcia-Ochoa, F. (2005). Production of a biocatalyst of Pseudomonas putida CECT5279 for DBT biodesulfurization: Influence of the operational conditions. Energy Fuels, 19; 775-782.
Martinez, I., Mohamed, M. E., Santos, V. E., Garcia, J. L., Garcia-Ochoa, F. and Diaz, E. (2017). Metabolic and process engineering for biodesulfurization in Gram-negative bacteria. J. Biotechnol., 262; 47-55.
Martinez, I., Santos, V. E., Alcon, A. and Garcia-Ochoa, F. (2015). Enhancement of the biodesulfurization capacity of Pseudomonas putida CECT5279 by co-substrate addition. Process Biochem., 50(1); 119-124.
Millard, P., Smallbone, K. and Mendes, P. (2017). Metabolic regulation is sufficient for global and robust coordination of glucose uptake, catabolism, energy production and growth in Escherichia coli. PLOS Comput. Biol., 13(2); 1-24.
Mohebali, G. and Ball, A. S. (2016). Biodesulfurization of diesel fuels-Past, present and future perspectives. Int. Biodeterior. Biodegrad. 110; 163-180.
Neijssel, O. M. and Tempest, D. W. (1976). Bioenergetic aspects of aerobic growth of Klebsiella aerogenes NCTC 418 in carbon-limited and carbon-sufficient chemostat culture. Arch. Microbiol., 107(2); 215-221.
Pirt, S. J. (1965). The maintenance energy of bacteria in growing cultures. Proc. R. Soc. London, Ser. B, 163(991); 224-231.
Pirt, S. J. (1982). Maintenance energy: a general model for energy-limited and energy-sufficient growth. Arch. Microbiol., 133(4); 300-302.
Razvi, A., Zhang, Z. and Lan, C. Q. (2008). Effects of glucose and nitrogen source concentration on batch fermentation kinetics of Lactococcus lactis under hemin-stimulated respirative condition. Biotechnol. Prog., 24(4); 852-858.
Repaske, D. R. and Adler, J. (1981). Change in intracellularr pH of Escherichia coli mediates the chemotactic response to certain attractants and repellents. J. Bacteriol., 145(3); 1196-1208.
Soleimani, M., Bassi, A. and Margaritis, A. (2007). Biodesulfurization of refractory organic sulfur compounds in fossil fuels. Biotechnol. Adv., 25(6); 570-596.
Srinivasan, K. and Mahadevan, R. (2010). Characterization of proton production and consumption associated with microbial metabolism. BMC Biotechnol., 10(2); 1-10.
Tsai, S. P. and Lee, Y. H. (1990). A model for energy-sufficient culture growth. Biotechnol. Bioeng., 35(2); 138-145.
van Bodegom, P. (2007). Microbial maintenance: A critical review on its quantification. Microb. Ecol., 53(4); 513-523.
Wang, Z. L., Wang, D., Li, Q., Li, W. L., Tang, H. and
Pollution, 5(4): 709-719, Autumn 2019
Pollution is licensed under a "Creative Commons Attribution 4.0 International (CC-BY 4.0)"
719
Xing, J. M. (2011). Enhanced biodesulfurization by expression of dibenzothiophene uptake genes in Rhodococcus erythropolis. World J. Microbiol. Biotechnol., 27(9); 1965-1970.
Zhou, J., Liu, L., Shi, Z., Du, G. and Chen, J. (2009). ATP in current biotechnology: Regulation, applications and perspectives. Biotechnol. Adv., 27(1); 94-101.
Zubay, G. L. (1998). Biochemistry. (Dubuque, Iowa: William C Brown Pub)