Abstract
The continuous enzymatic conversion of d-galactose to d-tagatose with an immobilized thermostable l-arabinose isomerase in packed-bed reactor and a novel method for d-tagatose purification were studied. l-arabinose isomerase from Thermoanaerobacter mathranii (TMAI) was recombinantly overexpressed and immobilized in calcium alginate. The effects of pH and temperature on d-tagatose production reaction catalyzed by free and immobilized TMAI were investigated. The optimal condition for free enzyme was pH 8.0, 60°C, 5 mM MnCl2. However, that for immobilized enzyme was pH 7.5, 75°C, 5 mM MnCl2. In addition, the catalytic activity of immobilized enzyme at high temperature and low pH was significantly improved compared with free enzyme. The optimum reaction yield with immobilized TMAI increased by four percentage points to 43.9% compared with that of free TMAI. The highest productivity of 10 g/L h was achieved with the yield of 23.3%. Continuous production was performed at 70°C; after 168 h, the reaction yield was still above 30%. The resultant syrup was then incubated with Saccharomyces cerevisiae L1 cells. The selective degradation of d-galactose was achieved, obtaining d-tagatose with the purity above 95%. The established production and separation methods further potentiate the industrial production of d-tagatose via bioconversion and biopurification processes.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Beadle JR, Saunders JP, Wajda Jr. TJ (1992) Process for manufacturing tagatose. US Patent, 5078796
Bertelsen H, Jensen BB, Buemann B (1999) d-tagatose—a novel low-calorie bulk sweetener with prebiotic properties. World Rev Nutr Diet 85:98–109
Bradford M (1976) A rapid and sensitive method for the quantification of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254
Buemann B, Toubro S, Raben A, Blundell J, Astrup A (2000) The acute effect of d-tagatose on food intake in human subjects. Brit J Nutr 84(2):227–231
Dische Z, Borenfreund E (1951) A new spectrophotometric method for the detection and determination of keto sugars and trioses. J Biol Chem 192:583–587
Donner TW (2006) The metabolic effects of dietary supplementation with d-tagatose in patients with type 2 diabetes. Diabetes 55 (Suppl. 1):A110
Donner T, Wilber J, Ostrowski D (1995) d-tagatose: a novel therapeutic adjunct for non-insulin-dependent diabetes. Diabetes 45(suppl 2):125a
Donner TW, Wilber JF, Ostrowski D (1999) d-tagatose, a novel hexose: acute effects on carbohydrate tolerance in subjects with and without type 2 diabetes. Diabetes Obes Metab 1(5):285–291
Freimund S, Huwig A, Giffhorn F, Köpper S (1996) Convenient chemo-enzymatic synthesis of d-tagatose. J Carbohydr Chem 15(1):115–120
Haltrich D, Leitner C, Neuhauser W, Nidetzky B, Kulbe KD, Volc J (1998) A convenient enzymatic procedure for the production of aldose-free d-tagatose. Ann NY Acad Sci 864(1):295–299
Izumori K, Tsuzaki K (1988) Production of d-tagatose from d-galactitol by Mycobacterium smegmatis. J Ferment Technol 66:225–227
Jorgensen F, Hansen OC, Stougaard P (2004) Enzymatic conversion of d-galactose to d-tagatose: heterologous expression and characterisation of a thermostable l-arabinose isomerase from Thermoanaerobacter mathranii. Appl Microbiol Biotechnol 64(6):816–822
Kim P (2004) Current studies on biological tagatose production using l-arabinose isomerase: a review and future perspective. Appl Microbiol Biotechnol 65(3):243–249
Kim BC, Lee YH, Lee HS, Lee DW, Choe EA, Pyun YR (2002) Cloning, expression and characterization of l-arabinose isomerase from Thermotoga neapolitana: bioconversion of d-galactose to d-tagatose using the enzyme. FEMS Microbiol Lett 212(1):121–126
Kim HJ, Ryu SA, Kim P, Oh DK (2003) A feasible enzymatic process for d-tagatose production by an immobilized thermostable l-arabinose isomerase in a packed-bed bioreactor. Biotechnol Progr 19(2):400–404
Levin GV, Zehner LR, Saunders JP, Beadle JR (1995) Sugar substitutes: their energy values, bulk characteristics, and potential health benefits. Am J Clin Nutr 62(5 Suppl):1161S–1168S
Li Z, Xiao M, Lu L, Li Y (2008) Production of non-monosaccharide and high-purity galactooligosaccharides by immobilized enzyme catalysis and fermentation with immobilized yeast cells. Process Biochem 43(8):896–899
Manzoni M, Rollini M, Bergomi S (2001) Biotransformation of d-galactitol to tagatose by acetic acid bacteria. Process Biochem 36(10):971–977
Oh DK (2007) Tagatose: properties, applications, and biotechnological processes. Appl Microbiol Biotechnol 76(1):1–8
Rhimi M, Bejar S (2006) Cloning, purification and biochemical characterization of metallic-ions independent and thermoactive l-arabinose isomerase from the Bacillus stearothermophilus US100 strain. Biochim Biophys Acta 1760(2):191–199
Szepesi B, Levin GV, Zehner LR, Saunders JP (1996) Antidiabetic effect of d-tagatose in SHR/N-cp rats. FASEB J 10(3):A461
Wei J, Yuan Q, Wang T, Wang L (2010) Purification and crystallization of xylitol from fermentation broth of corncob hydrolysates. Front Chem Eng China 4(1):57–64
Wong D (2000) Sweetener determined safe in drugs, mouthwashes, and toothpastes. Dent Today 19 (5):32, 34–35
Acknowledgments
The financial assistance provided by Natural Science Foundation of Shandong Province, China (nos. ZR2010CM057 and 2009ZRB019SQ) is gratefully acknowledged.
Author information
Authors and Affiliations
Corresponding authors
Rights and permissions
About this article
Cite this article
Liang, M., Chen, M., Liu, X. et al. Bioconversion of d-galactose to d-tagatose: continuous packed bed reaction with an immobilized thermostable l-arabinose isomerase and efficient purification by selective microbial degradation. Appl Microbiol Biotechnol 93, 1469–1474 (2012). https://doi.org/10.1007/s00253-011-3638-z
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00253-011-3638-z