L-Lysine (C6H14N2O2) one of the essential and commercially important amino acids is found in naturally occurring proteins of all living organisms. The steadily increasing L-Lysine demand indispensably necessitates its fermentative production over synthetic processes. In practice, most of the amino acids were produced by batch fermentation. Continuous fermentation processes have certain advantages over the traditional discontinuous processes. L-Lysine production using immobilized cells in continuous mode seem to be very promising for future applications. The method employed for immobilization is calcium alginate cross linked with gluteraldehyde entrapment. We made an attempt to investigate the dependence of dilution rate on substrate utilization rate and cell productivity in continuous culture studies. L-Lysine concentration improved to a maximum level of 45.34 g/L and yield was 0.55 (g/g) obtained at an optimum dilution rate of 0.3 (1/h) under operating conditions of fermentation time – 72 h, pH – 7.5, Temperature – 30 °C and glucose concentration of 90 g/L.

With the advent of new uses and growing markets of amino acids, the amino acid production technology has made significant progress during the latter half of the 20th century. The amino acid industry has been expanding and this industrial growth is expected to continue because of the incessant efforts to improve the established production processes. It is also expected to further reduce the production costs, thereby increasing the worldwide market. The development of low-cost fermentation processes for many kinds of amino acids and the recent rapid progress in biotechnology including strain improvement technology, progress in biochemical engineering, and downstream processing, indicate that fermentation The IUP Journal of Chemical Engineering, Vol. III, No. 2, 8 2011 attains a key position in the amino acid industry. Fermentation technology has played crucial roles over a period of time, and currently, amino acids produced by fermentation represent chief products of biotechnology in both volume and value (Ikeda, 2003).

Out of the 20 naturally occurring amino acids, L-Lysine is one of the nine essential amino acids and is a commercially important amino acid. It is added to improve the nutritional value of cereal-based diets, and is currently sold at approximately $3-4/kg. Presently, 80% of Lysine in the world market is manufactured by microbial fermentation and the remaining 20% by chemical synthesis. L-lysine is presently being used in the pharmaceutical, food, feed milling and cosmetic industries. Thus, the outlook for this amino acid is high because of its expanding market demand (Anastassiadis, 2007).

Corynebacterium, Continuous Stirred-Tank Reactor (CSTR), Immobilization, Kinetics, L-Lysine, Chemical Engineering Journal, Cross Linked Pva Membranes, Pervaporation Catalytic Membrane Reactor, Membrane Separation Process, Esterification Reactions, Plant Scale Production, Catalytic Membranes, Kinetic Model Equations, Regression Analysis, Pervaporation Reactors.