Metabolic flux analysis of Gluconacetobacter xylinus for bacterial cellulose production
Metabolic flux analysis was used to reveal the metabolic distributions in Gluconacetobacter xylinus (CGMCC no. 2955) cultured on different carbon sources. Compared with other sources, glucose, fructose, and glycerol could achieve much higher bacterial cellulose (BC) yields from G. xylinus (CGMCC no. 2955). The glycerol led to the highest BC production with a metabolic yield of 14.7 g/mol C, which was approximately 1.69-fold and 2.38-fold greater than that produced using fructose and glucose medium, respectively. The highest BC productivity from G. xylinus CGMCC 2955 was 5.97 g BC/L (dry weight) when using glycerol as the sole carbon source. Metabolic flux analysis for the central carbon metabolism revealed that about 47.96 % of glycerol was transformed into BC, while only 19.05 % of glucose and 24.78 % of fructose were transformed into BC. Instead, when glucose was used as the sole carbon source, 40.03 % of glucose was turned into the by-product gluconic acid. Compared with BC from glucose and fructose, BC from the glycerol medium showed the highest tensile strength at 83.5 MPa, with thinner fibers and lower porosity. As a main byproduct of biodiesel production, glycerol holds great potential to produce BC with superior mechanical and microstructural characteristics.
KeywordsBacterial cellulose Metabolic flux analysis Productivity Microstructure Crystallinity index
The authors are grateful for the financial support from the National Natural Science Foundation of China (project no. 21106105, project no. 20976133), the Foundation of Tianjin Educational Committee (no. 20100602), and Changjiang Scholars and Innovative Research Team in University (no. IRT1166). We also gratefully acknowledge Rebecca G. Ong for her assistance in editing this manuscript.
- Ma K, Zhao HX, Zhang C, Lu Y, Xing XH (2012) Impairment of NADH dehydrogenase for increased hydrogen production and its effect on metabolic flux redistribution in wild strain and mutants of Enterobacter aerogenes. Int J Hydrogen Energy. doi: 10.1016/j.ijhydene. 2012.08.017
- Naritomi T, Kouda T, Yano H, Yoshinaga F (1998) Effect of lactate on bacterial cellulose production from fructose in continuous culture. J Ferm Bioeng 85:89–95Google Scholar
- Park ST, Kim E, Kim YM (2006) Overproduction of cellulose in Acetobacter xylinum KCCM 10100 defective in GDP-mannosyltransferase. J Microbiol Biotechnol 16:961–964Google Scholar
- Ross P, Mayer R, Benziman M (1991) Cellulose biosynthesis and function in bacteria. Microbiol Rev 55:35–58Google Scholar
- Shigematsu T, Takamine K, Kitazato M, Morita T, Naritomi T, Morimura S, Kida K (2005) Cellulose production from glucose using a glucose dehydrogenase gene (gdh)-deficient mutant of Gluconacetobacter xylinus and its use for bioconversion of sweet potato pulp. J Biosci Bioeng 99:415–422CrossRefGoogle Scholar
- Sturcová A, His I, Apperley DC, Sugiyama J, Jarvis MC (2004) Structural details of crystalline cellulose from higher plants. Biomacromolecules 5:1333–1339Google Scholar
- Weinhouse H, Benziman M (1976) Phosphorylation of glycerol and dihydroxyacetone in Acetobacter xylinum and its possible regulatory role. J Bacteriol 127:747–754Google Scholar