Fed-batch culture for L-lysine production via on-line state estimation and control

Liu, Yung-Chuan; Wu, Wen‐Teng; Tsao, Jia-Huey

doi:10.1007/bf00389920

Cited by 15 publications

(2 citation statements)

References 18 publications

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“…Numerous articles have considered the optimum feed rate for fed-batch fermentation (Liu, 1993;Tartakovsky et al, 1995;Tremblay et al, 1993). Algorithms for the determination of the optimum feed rate profile result in a feedforward control law.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Candida rugosa lipase production by using different control fed‐batch operational strategies

Gordillo¹,

Sanz²,

Sánchez³

et al. 1998

Biotechnol. Bioeng.

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Simulation studies have predicted that maximum lipase activity is reached with fed-batch operation strategies. In this work, two different fed-batch operational strategies have been studied: constant substrate feeding rate and specific growth rate control. A constant substrate feeding rate strategy showed that maximum aqueous lipolytic activity (55 U/mL) was reached at low substrate feeding rates, whereas lipase tends to accumulate inside the cell at higher rates of substrate addition. In the second fed-batch strategy studied, a feedback control strategy has been developed based on the estimation of state variables (X and mu) from the measurement of indirect variables such as CER by means of mass spectrometry techniques. An on-off controller was then used to maintain the specific growth rate at the desired value by adjusting the substrate feeding rate. A constant specific growth rate strategy gave higher final levels of aqueous lipolytic activity (117 U/mL) at low specific growth rates. At higher specific growth rates the enzyme remained accumulated inside the cell, as was observed with a constant feeding fed-batch strategy. With a constant specific growth rate strategy, lipase production by Candida rugosa was enhanced 10-fold compared to a batch operation. Purification studies have demonstrated that lipolytic and esterasic specific activity ratios of Candida rugosa isoenzymes can be modified by using different operational conditions. These studies have also showed that the isoenzymes obtained in a controlled growth rate strategy are around three- to four-fold more active than those obtained in a constant feeding rate strategy.

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Section: Introductionmentioning

confidence: 99%

Enhancement of Candida rugosa lipase production by using different control fed‐batch operational strategies

Gordillo¹,

Sanz²,

Sánchez³

et al. 1998

Biotechnol. Bioeng.

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show abstract

“…Published papers dealing with the improvement of l ‐lysine fed‐batch fermentation performance by process manipulation investigate the effects of sugar concentrations and fed‐batch strategies. The studied fed‐batch strategies are characterized as constant feed rates, feed rate profiles based on optimal control theory, metabolic activity control with respiratory measurements as indirect indicators, and closed‐loop adaptive control with on‐line state estimation using respiratory measurements (Rutkov, 1984; Modak et al, 1986; Kiss and Stephanopoulus, 1991; Liu et al, 1993). More recently, excretion of l ‐lysine into the fermentation broth was investigated, and the effects of pH on the process performance were studied, as the carrier‐mediated export system of C. glutamicum is strongly dependent on the pH gradient across the cell membrane (Broer et al, 1993; Kelle et al, 1996; Krämer, 1996).…”

Section: Introductionmentioning

confidence: 99%

Substrate Controlled Fed‐Batch Production of l‐Lysine with Corynebacterium glutamicum

Weuster‐Botz

Kelle

Frantzen

et al. 1997

Biotechnology Progress

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A fed-batch process for the production of L-lysine with Corynebacterium glutamicum in a stirred tank reactor was developed up to a 150-L scale applying the general approach of reaction engineering: Experimental optimization of medium composition (13 components: mineral salts and biotin) in parallel shake-flask experiments using a Genetic Algorithm and the study of L-leucine, ammonia, and phosphate supply in glucose controlled fed-batch fermentations resulted in a volumetric L-lysine productivity of 8.3 mol/(m 3 ‚h), a L-lysine yield of 32% (mol/mol), and a L-lysine concentration of 500 mM. The glucose concentration was controlled to 50 mM using on-line HPLC and semicontinuous extended Kalman-filter with a minimum variance controller. Nitrogen accumulation of the C. glutamicum cells in the early process phase for subsequent L-lysine formation was identified by means of a reaction engineering analysis. Glucose limitation in the inoculum (1-2 h) results in growth linked L-lysine production with a differential L-lysine selectivity of 38% (mol/mol) and a maximum cell specific L-lysine production rate of 1.1 mmol/(g‚h). L-Lysine was not growth linked produced, if the inoculum was transferred at the exponential state.

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Enhancement ofCandida rugosa lipase production by using different control fed-batch operational strategies

Gordillo

Sanz

Sánchez

et al. 1998

Biotechnol. Bioeng.

View full text Add to dashboard Cite

Simulation studies have predicted that maximum lipase activity is reached with fed‐batch operation strategies. In this work, two different fed‐batch operational strategies have been studied: constant substrate feeding rate and specific growth rate control. A constant substrate feeding rate strategy showed that maximum aqueous lipolytic activity (55 U/mL) was reached at low substrate feeding rates, whereas lipase tends to accumulate inside the cell at higher rates of substrate addition. In the second fed‐batch strategy studied, a feedback control strategy has been developed based on the estimation of state variables (X and μ) from the measurement of indirect variables such as CER by means of mass spectrometry techniques. An on‐off controller was then used to maintain the specific growth rate at the desired value by adjusting the substrate feeding rate. A constant specific growth rate strategy gave higher final levels of aqueous lipolytic activity (117 U/mL) at low specific growth rates. At higher specific growth rates the enzyme remained accumulated inside the cell, as was observed with a constant feeding fed‐batch strategy. With a constant specific growth rate strategy, lipase production by Candida rugosa was enhanced 10‐fold compared to a batch operation. Purification studies have demonstrated that lipolytic and esterasic specific activity ratios of Candida rugosa isoenzymes can be modified by using different operational conditions. These studies have also showed that the isoenzymes obtained in a controlled growth rate strategy are around three‐ to four‐fold more active than those obtained in a constant feeding rate strategy. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 60: 156–168, 1998.

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Fed-batch culture for L-lysine production via on-line state estimation and control

Cited by 15 publications

References 18 publications

Enhancement of Candida rugosa lipase production by using different control fed‐batch operational strategies

Enhancement of Candida rugosa lipase production by using different control fed‐batch operational strategies

Substrate Controlled Fed‐Batch Production of l‐Lysine with Corynebacterium glutamicum

Enhancement ofCandida rugosa lipase production by using different control fed-batch operational strategies

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