Dissolved Oxygen concentration analysis of L-Lysine Fermentation Production by Corynebacterium glutamicum
D Rao, S Razak, B Praveena, A Swamy
dissolved oxygen tensions dot, fermentation, l-lysine
D Rao, S Razak, B Praveena, A Swamy. Dissolved Oxygen concentration analysis of L-Lysine Fermentation Production by Corynebacterium glutamicum . The Internet Journal of Pharmacology. 2007 Volume 6 Number 1.
The L-lysine fermentation by
Out of the twenty naturally occurring amino acids, L -lysine (C6H14N2O2; MW 146.19) is the one of the nine essential amino acid. It's major commercially form is L-lysine –HCL (L - lysine monohydrochloride (Liebl et al., 1991). L- Lysine is commonly produced in a stable and non-hygroscopic hydro chlorinated form of purity higher than 98.5% and moisture content less than 1% (Fechter et al., 1997). It is mainly used as a feed additive in the animal feed industry, mixed with various common live stock such as cereals which do not contain sufficient levels of L-lysine for the live stock's nutritional requirement especially for single stomach animals like broilers, poultry, and swine (Zelder, et al., 2005). (Ishii et al., 1997), and as supplement for humans, improving the feed quality by increasing the absorption of other amino acids. (Georgen et al., 1982). As a fine chemical it is used in human medicine, in cosmetics and in the pharmaceutical industry, particularly as ingredients of infusion solution for pharmaceutical application (Zelder et al., 2005) and as precursor for industrial chemicals. Further more, a production method for industrially producing an optically active lysine derivative useful as a pharmaceutical intermediate is described in Nakazawa et al., 2006. Several hundred thousand tones of L- lysine (800,000 tones/year) are presumably produced annually world wide, almost exclusively using bacterial fermentations. US6984512and WO2005/059139 (Zelder et al., 2005), (Liaw et al., 2006) refer to an annual L-lysine production of approximately 250,000tonnes, instead. Optimal oxygen transfer is perhaps the most difficult task to accomplish. Oxygen is poorly soluble in water -and even less in fermentation broths- and is relatively scarce in air (20.8%). Oxygen transfer is usually helped by agitation, which is also needed to mix nutrients and to keep the fermentation homogeneous. There is however limits to the speed of agitation, due both to high power consumption (that's proportional to the cube of the speed) and the damage to organisms due to excessive tip speed. No significant information has been found in patent literature regarding the effect of air saturation and a little is known regarding the real effect of oxygen on L-lysine fermentation. L-lysine fermentation is an aerobic process [Shimazaki et al., 1983, Tosaka et al., 1981, Asakura etal. 1999] demanding large amounts of oxygen and strongly influenced by the air saturation in bioreactor. Lactic acid is formed as a byproduct under anaerobic conditions, which is reconsumed after the establishment of aerobic conditions. Aerobic conditions are maintained by aseptically adding to the culture oxygen containing gaseous mixtures, e.g. atmospheric air or pure oxygen [Kreutzer et al., 2001
The critical DOC and its limitation
The effect of the DOC to the specific microbial oxygen uptake rate can be described by the Michaelis–Menten o r Monod type of expression.
Material and Methods
Variation of Dissolved Oxygen Tension
A dissolved Oxygen Tensions effect strain (
Results and Discussions
Variation of dissolved oxygen tension is in the range of 5%, 10% and 20%. From this highest amount of lysine formation is taking place at 20% (52.7 g/lit). The results are show in table 2 and figure 2. .
Rpm ---- 300
Temperature ---- 30 °C
Rpm ---- 300
Temperature ---- 30 °C
By variation of different parameters in stirred tank bioreactor the high amount of lysine production is takes place as follows by varying, rpm, temperature, inoculum composition. By variation of Dissolved Oxygen tension at 20% (52.7g/lit) high amount of is lysine obtained.
Dr.Dowlathabad Muralidhara Rao M.Sc.,M.Phil., Ph.D. Asst.Professor Bioprocess Laboratory Department of Biotechnology SriKrishnadevaraya University Anatapur -515003 A.P. INDIA http://www.sku-biotech.org http://www.skuniversity.org