Production of L-Lactic Acid from Corn Starch Hydrolysate by Immobilized Rhizopus oryzae on a New Asterisk-Shaped Matrix

Abstract:

A new asterisk-shaped matrix composed of stainless-steel mesh and cotton cloth was emloyed for immobilizing Rhizopus oryzae As3.3462 cells. The ability of the immobilized cells to produce L-lactic acid was evaluated by using corn starch hydrolysate as carbon sources. The cells were attached onto the matrix with nearly 100% efficiency within 5 h and demonstrated asterisk mycelia morphology rather than a pellet-like cake as exhibited by the free-cells. Consequently, the immobilization fermentation resulted in higher L-lactic acid concentration (82.79 g.L-1 vs 48.23 g.L-1) within a shorter time (60 h vs 72 h) than the free fermentation. In addition, the stability of the immobilized cells for a long-term fermentation was investigated in 8 consecutive fermentation batches for 30 days. The maximum variation of L-lactic acid concentration among these batches was less than 10%. These results imply that the proposed asterisk matrix is good for Rhizopus oryzae immobilization and provids a simple and feasible fermentation strategy for L-lactic acid production.

• Periodical: Advanced Materials Research (Volumes 347-353)
• Pages: 1193-1197
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.347-353.1193
• Online since: October 2011
• Authors: Xin Chen, Bing Bing Zhang, Yuan Liang Wang, Yan Feng Luo, Run Guang Wang, Hui Qing Ren, Hong Ji Xu
• Keywords: Corn Starch Hydrolysate, Immobilization Fermentation, L-Lactic Acid, Rhizopus oryzae

References

[1] M.C. Yu, R.C. Wang, C.Y. Wang, K.J. Duan, D.C. Sheu, Enhanced production of L(+)-lactic acid by floc-form culture of Rhizopus oryzae, J. Chinese Institute Chem. Eng. 38(2007)223-228.

DOI: 10.1016/j.jcice.2007.02.005

[2] J. Yan, R. Bajpai, E. Iannotti, M. Propovic, R. Muller, Lactic acid fermentation from enzyme-thinned starch with immobilized Lactobacillus amylovorus, Chem. Biochem. Eng. 15(2001) 59-63.

[3] Wang Z, Wang YL, Yang SJ, Wang RG, Ren HQ, A novel honeycomb matrix for cell immobilization to enhance lactic acid production by Rhizopus oryzae, Biores. Technol. 101(2010)5557-5564.

DOI: 10.1016/j.biortech.2010.02.064

[4] L.H. Grimm, Morphology and productivity of filamentous fungi, Appl. Microbiol. Biotechnol. 69(2005)375-384.

DOI: 10.1007/s00253-005-0213-5

[5] W. Liao, Y. Liu, S.L. Chen, Studying pellet formation of a filamentous fungus Rhizopus oryzae to enhance organic acid production, Appl. Biochem. Biotechnol. 136(2007)689-702.

DOI: 10.1007/s12010-007-9089-4

[6] R. Ganguly, P. Dwivedi, R.P. Singh, Production of lactic acid with loofa sponge immobilized Rhizopus oryzae RBU2-10, Biores. Technol. 98(2007)1246-1251.

DOI: 10.1016/j.biortech.2006.05.004

[7] N.D. Roble, J.C. Ogbonna, H. Tanaka, L-Lactic acid production from raw cassava starch in a circulating loop bioreactor with cells immobilized in loofa (LuVa cylindrica), Biotechnol. Lett. 25(2003)1093-1098.

DOI: 10.1007/s00253-002-1119-0