Improving the stability of glutamate fermentation by Corynebacterium glutamicum via supplementing sorbitol or glycerol

Abstract

Background

Corynebacterium glutamicum is widely used in glutamate fermentation. The fermentation feature of the strain varies sometimes. These variations may lead to the reduction in the ability of the strain to resist environmental changes and to synthesize glutamate, resulting in abnormal glutamate fermentations.

Results

In the abnormal glutamate fermentations, glutamate accumulation stopped after glucose feeding and the final glutamate concentration was at a lower level (50 to 60 g/L). The r_NAD ⁺/r_NADH ratio was lower than that in normal batch which was reflected by lower oxidation-reduction potential (ORP) value. The abnormal fermentation performance was improved when glucose was co-fed with sorbitol/glycerol at a weight ratio of 5:1 or adding 10 to 15 g/L of sorbitol/glycerol in the initial medium. Under these conditions, glutamate synthesis continued after substrate(s) feeding and final glutamate concentration was restored to normal levels (≥72 g/L). r_NAD ⁺/r_NADH ratio, ORP, and pyruvate dehydrogenase (PDH), isocitrate dehydrogenase (ICDH), and cytochrome c oxidase (CcO) activities were maintained at higher levels.

Conclusions

Sorbitol and glycerol were not used as carbon sources for the fermentation. They were considered as effective protective agents to increase cells' resistance ability against environmental changes and maintain key enzymes activities.

Keywords

Enzyme activity / Fermentative stability / Glutamate fermentation / Oxidation-reduction potential / Protective substance / r_NAD ⁺/r_NADH

References

[1.] Sano C. History of glutamate production. Am J Clin Nutr, 2009, 90: 728S-732S.

[2.] Ying WH. NAD(+) and NADH in cellular functions and cell death. Front Biosci, 2006, 11: 3129-3148.

[3.] de Graef MR, Alexeeva S, Snoep JL, Teixeira de Mattos MJ. The steady-state internal redox state (NADH/NAD) reflects the external redox state and is correlated with catabolic adaptation in Escherichia coli. J Bacteriol, 1999, 181: 2351-2357.

[4.] Berrios-Rivera SJ, Bennett GN, San KY. The effect of increasing NADH availability on the redistribution of metabolic fluxes in Escherichia coli chemostat cultures. Metab Eng, 2002, 4: 230-237.

[5.] Kastner JR, Eiteman MA, Lee SA. Effect of redox potential on stationary-phase xylitol fermentations using Candida tropicalis. Appl Microbiol Biot, 2003, 63: 96-100.

[6.] Li J, Jiang M, Chen KQ, Ye Q, Shang LA, Wei P, Ying HJ, Chang HN. Effect of redox potential regulation on succinic acid production by Actinobacillus succinogenes. Bioproc Biosyst Eng, 2010, 33: 911-920.

[7.] Radjai MK, Hatch RT, Cadman TW. Optimization of amino acid production by automatic self tuning digital control of redox potential. Biotechnol Bioeng Symp, 1984, 14: 657-679.

[8.] Bhatnagar A, Srivastava SK. Aldose reductase: congenial and injurious profiles of an enigmatic enzyme. Biochem Med Metab Biol, 1992, 48: 91-121.

[9.] Azizi A, Ranjbar B, Khajeh K, Ghodselahi T, Hoornam S, Mobasheri H, Ganjalikhany MR. Effects of trehalose and sorbitol on the activity and structure of Pseudomonas cepacia lipase: spectroscopic insight. Int J Biol Macromol, 2011, 49: 652-656.

[10.] Wang Z, Wang Y, Zhang D, Li J, Hua Z, Du G, Chen J. Enhancement of cell viability and alkaline polygalacturonate lyase production by sorbitol co-feeding with methanol in Pichia pastoris fermentation. Bioresource Technol, 2010, 101: 1318-1323.

[11.] Liu Y, Zhang YG, Zhang RB, Zhang F, Zhu J. Glycerol/glucose co-fermentation: one more proficient process to produce propionic pcid by Propionibacterium acidipropionici. Curr Microbiol, 2011, 62: 152-158.

[12.] John GSM, Gayathiri M, Rose C, Mandal AB. Osmotic shock augments ethanol stress in Saccharomyces cerevisiae MTCC 2918. Curr Microbiol, 2012, 64: 100-105.

[13.] Ramon R, Ferrer P, Valero F. Sorbitol co-feeding reduces metabolic burden caused by the overexpression of a rhizopus oryzae lipase in Pichia pastoris. J Biotechnol, 2007, 130: 39-46.

[14.] Arruda PV, Felipe MGA. Role of glycerol addition on xylose-to-xylitol bioconversion by Candida guilliermondii. Curr Microbiol, 2009, 58: 274-278.

[15.] Popova O, Ismailov S, Popova T, Dietz KJ, Golldack D. Salt-induced expression of NADP-dependent isocitrate dehydrogenase and ferredoxin-dependent glutamate synthase in Mesembryanthemum crystallinum. Planta, 2002, 215: 906-913.

[16.] Hasegawa T, Hashimoto KI, Kawasaki H, Nakamatsu T. Changes in enzyme activities at the pyruvate node in glutamate-overproducing Corynebacterium glutamicum. J Biosci Bioeng, 2008, 105: 12-19.

[17.] Gourdon P, Lindley ND. Metabolic analysis of glutamate production by Corynebacterium glutamicum. Metab Eng, 1999, 1: 224-231.

[18.] Skjerdal OT, Sletta H, Flenstad SG, Josefsen KD, Levine DW, Ellingsen TE. Changes in intracellular composition in response to hyperosmotic stress of NaCl, sucrose or glutamic acid in Brevibacterium lactofermentum and Corynebacterium glutamicum. Appl Microbiol Biotechnol, 1996, 44: 635-642.

[19.] Park SM, Sinskey AJ, Stephanopoulos G. Metabolic and physiological studies of Corynebacterium glutamicum mutants. Biotechnol Bioeng, 1997, 55: 864-879.

[20.] Xiao J, Shi ZP, Gao P, Feng HJ, Duan ZY, Mao ZG. On-line optimization of glutamate production based on balanced metabolic control by RQ. Bioproc Biosyst Eng, 2006, 29: 109-117.

[21.] Savinell JM, Palsson BO. Network analysis of intermediary metabolism using linear optimization. I. Development of mathematical formalism. J Theor Biol, 1992, 154: 421-454.

[22.] Lin H, Bennett GN, San KY. Effect of carbon sources differing in oxidation state and transport route on succinate production in metabolically engineered Escherichia coli. J Ind Microbiol Biotechnol, 2005, 32: 87-93.

[23.] Murarka A, Dharmadi Y, Yazdani SS, Gonzalez R. Fermentative utilization of glycerol by Escherichia coli and its implications for the production of fuels and chemicals. Appl Environ Microb, 2007, 74: 1124-1135.

[24.] Farver O, Grell E, Ludwig B, Michel H, Pecht I. Rates and equilibrium of CuA to heme a electron transfer in paracoccus denitrificans cytochrome c oxidase. Biophys J, 2006, 90: 2131-2137.