Thursday, April 22, 2010 - 3:00 PM
12-04
Fermentative production of L-lysine-L-lactate from fractional green juices from a green biorefinery
Sebastian Leiss, Research Institute Bioactive Polymer Systems e.V., Kantstrasse 55, Teltow, 14513, Germany
For a future biobased economy, lactic acid is an important starting substance for industrial important intermediate products like acetaldehyde or acrylic acid[1]. Aminium lactates have been shown to be a good feedstock for the synthesis of dilactide without the formation of byproducts. They can be produced in a lactic acid fermentation by using aqueous solutions of organic amines as pH-correction solution. L-lysine-L-lactate was produced by using 50% L-lysine for pH-correction and different fractions of green juice as fermentation medium. Green juice is formed during the first separation step in a green biorefinery, where green biomasses are separated into a press cake and a press juice[2]. The juice contains carbohydrates, proteins, free amino acids, inorganic salts which are essential for microbial growth and can therefore be used as fermentation medium for lactic acid bacteria. In a second refining step these compounds should be separated [3]. To find out in which way the separation of proteins affects the fermentation, non-treated juice and deproteinized juice were compared with MRS-medium. It could be shown that at a glucose concentration of 50 g/l the separation of proteins had no effect onto the production rates, whereas a glucose concentration of 100 g/l showed explicit nutrient limitation compared to the fermentation with MRS-medium. The production rate decreased about 33% and the lactic acid yield dropped about 6%. However, these trials show that the fermentative production of L-lysine-L-lactate can be integrated into the system Green Biorefinery, where deproteinized press juice accrues as a product.
[2] S. Kromus, B. Wachter, W. Koschuh, M. Mandl, C. Krotscheck, M. Narodoslawsky, Chemical and Biochemical Engineering Quarterly 2004, 18, 8–12.
[3] B. Kamm, P. Schönicke, M. Kamm, CLEAN - Soil, Air, Water 2009, 37, 27-30.