Production of Alternansucrase byLeuconostoc mesenteroidesNRRL B-1355 in Batch Fermentation with Controlled pH and Dissolved Oxygen

Abstract

The effect of controlled pH and dissolved oxygen (DO) tension on the production of total glucosyltransferase activity (GTF), extracellular GTF and alternansucrase was studied in controlled batch fermentations of Leuconostoc mesenteroides NRRL B‐1355. Controlled aeration had a positive effect on the production of extracellular GTF in pH‐uncontrolled fermentations. An aerated batch fermentation controlled at 90% DO at controlled pH 6·7 resulted in complete utilisation of the carbon source. At controlled pH 5·5, maximal extracellular GTF (0·6 U cm−3), total GTF (3·4 U cm−3) and alternansucrase activities (1·2 U cm−3) were higher in a controlled aerated (75% DO) batch fermentation than in a non‐aerated batch fermentation. Acetic acid production was lowest in the non‐aerated fermentation process. Controlled DO batch fermentations carried out at pH 5·5, 6·0 and 6·5 resulted in an increasing energy efficiency. While highest alternansucrase activity (1·5 U cm−3) occurred in pH 6·5 controlled batch cultures, the highest total GTF activity (3·4 U cm−3) was found in the pH 5·5 controlled fermentation. © 1997 SCI.

Leuconostoc dextransucrase and dextran: production, properties and applications

“…Their physical and chemical properties are distinct from those of class 1 dextrans and they are completely resistant to endodextranase hydrolysis. For these reasons, they are termed alternan instead of dextran 87, 88. Recently, a mutant derivative of strain NRRL B‐1355 was reported to produce a third polysaccharide, an insoluble α‐ D ‐glucan containing linear (1,3)‐ and (1,6)‐linkages with (1,2)‐ and (1,3)‐branch points 89, 90…”

Identification of an α-(1,4)-Glucan-Synthesizing Amylosucrase from Cellulomonas carboniz T26

“…1 Lactic acid bacteria may use sucrose to synthesize a diversity of long-chain α-glucans with different linkages by various glycoside hydrolase family 70 glucansucrases (or glucosyltransferases). 2 For instance, dextransucrase (EC 2.4.1.5) generates α-glucans mainly composed α- (1,6) linkages; 3 mutansucrase (EC 2.4.1.125) catalyzes the biosynthesis of α-(1,3)-glucan, termed mutan; 4 alternansucrase (EC 2.4.1.140) 5 and reuteransucrase (EC 2.4.1.-) 6 catalyze the D-glucosyl residue polymerization from sucrose to produce α-(1,6)-α-(1,3)-glucan, termed alternan; and α-(1,6)-α-(1,4)-glucan, termed reuteran, respectively. In addition, a glycoside hydrolase family 13 enzyme, amyloscurase (AS) (sucrose:1,4-α-D-glucan 4-α-D-glucosyltransferase, EC 2.4.1.4) converts sucrose to α-glucan with only α-(1,4) linkages.…”