Reuteran, which is synthesized by reuteransucrase, is a complex α-glucan that is differentiated in part by the large amount of α(1-4) and α(1-6) linkages.[1] The polysaccharide is made of repeating monosaccharide units of D-glucose.[2] The glucose units are connected via alpha glyosidic bonds between the first carbon on one glucose to the fourth carbon on the next glucose molecule. Additional branching αlpha linkages occur between the sixth carbon of a glucose molecule and then the first carbon of the subsequent glucose molecule. These branches occur approximately every 5-7 glucose units.[3]
Synthesis
editReuteran is synthesized by an extracellular enzyme called reuteransucrase often found in Lactobacillus reuteri which is part of the lactic acid bacteria family.[1][3][4] Bacterial cells secrete reuteransucrase into the environment around them which then binds to sucrose and hydrolyze it into glucose and fructose. The glucose monomers are polymerized together in α(1-4) and α(1-6) glycosidic bonds. The fructose can be used for other metabolic purposes within the cell, or converted to glucose.[5] Around 70% of the bonds formed are 1-4 linkages.[4]
Uses
editReuteran has a low digestibility in the human digestive tract which causes it to act similar to an insoluble fiber in the human digestive tract.[6] Similar to other exopolysaccharides produced by lactic acid bacteria it can be used in the food industry. It can be used as a thickening agent, or to add texture to food products.[1]
References
edit- ^ a b c Meng, Xiangfeng; Pijning, Tjaard; Dobruchowska, Justyna M.; Yin, Huifang; Gerwig, Gerrit J.; Dijkhuizen, Lubbert (2016-10-17). "Structural determinants of alternating (α1 → 4) and (α1 → 6) linkage specificity in reuteransucrase of Lactobacillus reuteri". Scientific Reports. 6 (1): 35261. Bibcode:2016NatSR...635261M. doi:10.1038/srep35261. ISSN 2045-2322. PMC 5066211. PMID 27748434.
- ^ Kralj, S.; van Geel-Schutten, G. H.; van der Maarel, M. J. E. C.; Dijkhuizen, L. (2004-07-01). "Biochemical and molecular characterization of Lactobacillus reuteri 121 reuteransucrase". Microbiology. 150 (7): 2099–2112. doi:10.1099/mic.0.27105-0. ISSN 1350-0872. PMID 15256553.
- ^ a b Pijning, Tjaard; Vujičić-Žagar, Andreja; Kralj, Slavko; Dijkhuizen, Lubbert; Dijkstra, Bauke W. (2012-12-01). "Structure of the α-1,6/α-1,4-specific glucansucrase GTFA from Lactobacillus reuteri 121". Acta Crystallographica Section F. 68 (12): 1448–1454. doi:10.1107/S1744309112044168. ISSN 1744-3091. PMC 3509963. PMID 23192022.
- ^ a b Kralj, S.; Stripling, E.; Sanders, P.; van Geel-Schutten, G. H.; Dijkhuizen, L. (July 2005). "Highly Hydrolytic Reuteransucrase from Probiotic Lactobacillus reuteri Strain ATCC 55730". Applied and Environmental Microbiology. 71 (7): 3942–3950. Bibcode:2005ApEnM..71.3942K. doi:10.1128/AEM.71.7.3942-3950.2005. ISSN 0099-2240. PMC 1169070. PMID 16000808.
- ^ Kralj, Slavko; van Leeuwen, Sander S; Valk, Vincent; Eeuwema, Wieger; Kamerling, Johannis P; Dijkhuizen, Lubbert (2008-12-01). "Hybrid reuteransucrase enzymes reveal regions important for glucosidic linkage specificity and the transglucosylation/hydrolysis ratio". The FEBS Journal. 275 (23): 6002–6010. doi:10.1111/j.1742-4658.2008.06729.x. ISSN 1742-4658. PMID 19016850.
- ^ Yang, Yuqi; Sun, Yujing; Zhang, Tao; Hamaker, Bruce R.; Miao, Ming (April 2023). "Biofabrication, structure, and functional characteristics of a reuteran-like glucan with low digestibility". Carbohydrate Polymers. 305: 120447. doi:10.1016/j.carbpol.2022.120447. PMID 36737220.