MICROBIAL CATALYSTS TO PRODUCE FUEL ETHANOL AND VALUE ADDED PRODUCTS
Location: National Center for Agricultural Utilization Research
Title: Production of Value-added Products by Lactic Acid Bacteria
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: January 10, 2010
Publication Date: May 1, 2010
Citation: Liu, S., Li, Y., Azaizeh, H., Cui, F., Tafesh, A., Bischoff, K.M. 2010. Production of value-added products by lactic acid bacteria. In: Hou, C.T., Shaw, J.-F., editors. Biocatalysis and Molecular Engineering. New York: John Wiley and Sons. p. 421-435.
Lactic acid bacteria (LAB) are a group of facultative anaerobic, catalase negative, nonmotile and nonsporeforming–Gram positive bacteria. Most LAB utilize high energy C sources including monomer sugars to produce energy to maintain cellular structure and function. This anaerobic fermentation process also produces low energy end-products, primarily lactic acid. Based on the metabolic routes of given substrates and corresponding end products, LAB can be divided into homofermentative and heterofermentative.
Homofermentative LAB use the Embden-Meyerhof pathway to generate lactate as the sole fermentation product, while heterofermentative LAB use the pentose phosphoketolase pathway producing a mixture of lactate, ethanol, CO2, and acetate. LAB is widely used in agriculture and food processing industries as well as in medicine and immunological research. In this chapter, we focus on production of lactate, antibacterial peptides, and antifungal agents by lactic acid bacteria. Potential sustainable, renewable, and commercially viable production of value-added products by lactic acid bacteria is discussed.