Succinate production

It has been suggested by Podesta et al. (650) that ambient C02 levels determine the amount of succinate and lactate excreted by intestinal helminths. A summary of the events which they propose lead to succinate accumulation in H. diminuta is provided in Fig. 5.7. There is considerable release of C02 in the post-prandial intestine of the rat host as the acidic chyme is passed into the duodenum and there is an acidification of worm tissues as the C02 diffuses in. The acidification is countered by worm secretion of H+ and by mobilisation of Ca2 + from the calcareous corpuscles (Chapter 4), thus releasing carbonate. The increased osmolality and greater HC03 concentration activate PEPCK, which favours succinate production over lactate. Succinate, being a dicarboxylic acid, is twice as effective as lactate in metabolic disposal of H+. With a decrease in passage of stomach chyme into the intestine, there would be a decrease in acid stress on the worms, accompanied by a concomitant decrease in tissue HC03 concentrations and osmolality, which would favour lactate production. 

Wang Q, Chen X, Yang Y et al (2006) Genome-scale in silica aided metabolic analysis and flux comparisons of Escherichia coli to improve succinate production. Appl Microbiol Biotechnol 73 887-894... 

Japan s IRe Chemicals also offers a polybutylene succinate product under the trade name EnPol 4000. Mitsubishi Gas Chemicals offers a PBS based synthetic biopolymer under the Iupex trade name. 

Oxaloacetate is derived from succinate by the sequential action of succinate dehydrogenase, fumarase, and malate dehydrogenase. When levels of oxaloacetate are high, one would expect the activity of the enzyme to be reduced. Low levels of oxaloacetate would call for an increase in succinate production. 

Vemuri, G.N., Eiteman, M.A., and Altman, E. (2002) Succinate production in dual-phase Escherichia coli fermentations depends on the time of transition from aerobic to anaerobic conditions. /. Ind. Microbiol Biotechnol, 28, 325-332,... 

Zhang, X. et al (2009) Metabolic evolution of energy-conserving pathways for succinate production in Escherichia coli. Proc. Natl. Acad. Scl U.S.A., 106, 20180-20185. 

Inui, M., Murakami, S., Okino, S., Kawaguchi, H., Vertes, A.A., and Yukawa, H. (2004) Metabolic analysis of Corynebacterium glutamicum during lactate and succinate productions under oxygen deprivation conditions. / MH. Microbiol. Biotechnol, 7 (4), 182-196. 

Purification Processing Train for Ammonium Succinate Production... 

The purification processing train for ammonium succinate production consists of the following sequence of unit operations ... 

Martmez I, Bennett GN, San K-Y. (2010). Metabolic impact of the level of aeration during cell growth on anaerobic succinate production by an engineered Escherichia coli strain. Metab Eng, 12, 499-509. 

Microorganisms for Bio-Succinate Production—Physiology, Metabolic Routes, and Strain Development... 

MICROORGANISMS FOR BIO-SUCCINATE PRODUCTION-PHYSIOLOGY, METABOLIC ROUTES, AND STRAIN DEVELOPMENT... 

General metabolic routes for succinate production and by-product accumulation... 

TABLE 16.1 Selection of Superior Succinate Producer Organisms, the Corresponding Production Conditions and Important Production Parameters of the Resulting Succinate Production Processes Utilizing Two Important Model Substrates for Implementation in the Concept of Biorefinery—Glucose and Glycerol... 

Escherichia coli is a facultative anaerobe which can grow in the absence of oxygen either by various types of anaerobic respiration or by mixed acid fermentation. In the latter type of catabolism, succinate is formed as an end product besides acetate, lactate, ethanol, and formate. In the past years, a multitude of studies was published on the engineering of E. coli metabolism for increased succinate production (Wendisch... 

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