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Open AccessJournal ArticleDOI

The effect of certain cultural factors on production of dextransucrase by Leuconostoc mesenteroides.

TLDR
Observation on factors affecting production of dextransucrase from Leuconostoc mesenteroides, strain NRRL B-512 and the possibility that more than one enzyme may be involved in the synthesis ofdextran is recognized.
Abstract
Present knowledge on the characteristics of dextransucrase and its mode of action is based primarily on the important investigations of Hehre (1941, 1946, 1951) and Hehre and Sugg (1942). Hitherto, a serious impediment to studies of this interesting enzyme has been the difficulty of procuring dextransucrase. Development of further knowledge about it would be greatly facilitated by the availability of culture liquors rich in dextransucrase. The rapid formation of dextransucrase in high yields has been reported in a preliminary note (Koepsell and Tsuchiya, 1952). The present report deals in greater detail with our observations on factors affecting production of dextransucrase from Leuconostoc mesenteroides, strain NRRL B-512.2 However, culture liquors high in activity have been obtained from a large number of the organisms tested. The dextran produced by strain NRRL B-512 in the conventional whole culture procedure contains about 95 per cent a-1,6-glucopyranosidic linkage. Although the non-1,6 linkages have been assumed to be of the a-1,4 type, definite proof on this point is lacking (Jeanes and Wilham, 1950). L. mesenteroides, strain NRRL B-512, or its substrains, is the organism principally used in investigations of clinical dextran in the United States. Although the term \"dextransucrase\" is used in the singular for convenience, the possibility that more than one enzyme may be involved in the synthesis of dextran is recognized.

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Citations
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Journal ArticleDOI

Glucansucrases produced by fructophilic lactic acid bacteria Lactobacillus kunkeei H3 and H25 isolated from honeybees

TL;DR: The results suggest a more branched structure of the studied polymers, suggesting exopolysaccharide synthesis in honeybee stomachs.
Journal ArticleDOI

Comparative study of production of dextransucrase and dextran by cells of Leuconostoc mesenteroides immobilized on Celite and in calcium alginate beads.

TL;DR: It is expected that larger amounts of enzymatic activity than measured are immobilized inside the alginate‐coated Celite R630 and calciumAlginate beads due to the mass transfer limitation conferred by the dextran product formed therein.
Journal ArticleDOI

Inhibition of the flocculation of bacteria by biopolymers

TL;DR: The bacterium Leuconostoc was used as a model in a study of the effect of bacterial polymers on flocculation, and the presence of large quantities of natural or artificial polymers can act to stabilize bacterial suspensions and prevent flocculating.
Journal ArticleDOI

Studies on the enzyme dextransucrase. III. Further evidence for the presence of imidazole at the catalytic site of the enzyme

TL;DR: The hypothesis that imidazole plays an important role in the catalytic activity of dextransucrase has been further substantiated based on an application of the photooxidation technique for destroying the imdazole portion of histidine in proteins.
Journal ArticleDOI

Proteolytic modification of Leuconostoc mesenteroides B-512F dextransucrase.

TL;DR: Although no structural differences were found in dextrans synthesized with both the precursor and the proteolyzed 155 kDa form under the same reaction conditions, their rheological behaviour was modified, with dextran of a lower viscosity yielded by the smaller form.
References
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Journal ArticleDOI

Enzymatic synthesis of dextran

TL;DR: A study of acceptor specificity in dextran synthesis was undertaken with the object of elucidating the polymerization mechanism and it was hoped that clues leading to the direct enzymatic synthesis of “clinical” dextransucrase with an average molecular weight in the range of 50,000 to 100,000 would be found.
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