Research on Producation of a New Type of Biological High Molecular Material Poly(γ-Glutamic Acid)

Abstract:

Poly-γ-glutamic acid (γ-PGA) is a kind of water-soluble and biodegradable polymer, as a potential targeted biopolymer that can be refined from biomass directly. In this work, the effect of environmental parameters on γ-PGA formation by Bacillus licheniformis is investigated . The influence of culture temperature, pH and culture time on cell growth, γ-PGA production and molecular weight, polymer stereochemistry are determined. The γ-PGA yield is higher(30.13g/L) at culture temperature 37 , pH 7.0. Alteration of the medium pH, temperature, culture time and aeration had little to no significant effects on the product quality as measured by stereochemical composition. But alteration of the medium pH, temperature, culture time and aeration have obvious effects on the γ-PGA yield and molecular weight, increasing the biomass and γ-PGA yields. Under the optimal environmental conditions yields of γ-PGA in excess of 36g/L is obtained in submerged culture. Finally, the large-scale fermentation of γ-PGA production was successfully scaled up to a 100-l fermentor, with the highest γ-PGA productivity for over 57.5 g/l.

• Periodical: Advanced Materials Research (Volumes 189-193)
• Pages: 142-146
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.189-193.142
• Online since: February 2011
• Authors: Ge Yang, Wang Ning, Chao Zhang
• Keywords: Bacillus licheniformis, Cultivation Condition, Optimization, Poly-γ-Glutamic Acid, Scale-Up

References

[1] Makoto A., Tohru K., Haruo M. ：Journal of Molecular Catalysis. B, Enzymatic 23（2003）, pp.101-106.

[2] Richie S. M. C., Bachas L. G., Olin T.: Langmuir 15 (1999), pp.6346-6357.

[3] Shi F., Xu Z. N., Cen, P. L.: Science in China Series B, Chemistry 50(2007), pp.291-303.

[4] Goto, A., & Kunioka, M.: Bioscience Biotechnology and Biochemistry, 63(1992), pp.101-105.

[5] Ko Y. H., Richard A. G.: Biotechnology and Bioengineering 57(1997), 430-437.

[6] Cromwick A. M., Birrer G. A., Gross R. A.: Biotechnology and Bioengineering 50(1996), pp.222-227.

[7] Shi F., Xu Z. N., Cen P. L.: Biotechnology and Bioprocess Engineering 11(2006), pp.251-257.

[8] Shi F., Xu Z. N., Cen, P. L.: Applied Biochemistry and Biotechnology 133(2006), pp.271-281.

[9] Du Guocheng, Yang Ge, Chen Jian: Process Biochemistry 40(2005), p.2143–2147.

[10] Birr G. A., Cromwick A. M., Gross, R. A.: International Journal of Biological Macromolecules 16(1994), pp.265-275.