Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The uptake kinetics of sugars present in wheat doughs and alpha-glucosidase as well as beta-fructosidase activities were determined in different strains of yeasts and lactic acid bacteria. These strains were previously selected according to their breadmaking quality. Saccharomyces cerevisiae (P6), Candida guilliermondii (P40), Lactobacillus plantarum (B31 and La18) and L. brevis (B21) showed good performance, while Sacch. fructuum (P43), L. cellobiosus (B37) and Enterococcus faecium (B11) yielded bread of lower quality. Leuconostoc mesenteroides (B10), when used in combination with other strains led also to high quality starters. All yeast strains used assimilated glucose, fructose and maltose, exhibiting saturable kinetics. Lactic acid bacteria showed saturable kinetics only for hexoses, whereas disaccharide uptake was linear. Sacch. cerevisiae, Leuconostoc mesenteroides, L. brevis and L. plantarum (B31) displayed better sugar uptake properties. For all the strains used alpha-glucosidase and beta-fructosidase activities were detected. The highest specific activities were found for Sacch. cerevisiae, C. guilliermondii and L. plantarum (B31). These results indicate good correlation between the parameters evaluated and the breadmaking potential of the microorganisms.
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PMID:Sugar uptake and involved enzymatic activities by yeasts and lactic acid bacteria: their relationship with breadmaking quality. 849 88

The regulation of extracellular enzymes is of great biotechnological interest. We studied the regulatory role of the URE2 gene on the periplasmic invertase of Saccharomyces cerevisiae, because its periplasmic asparaginase is regulated by the URE2/GLN3 system. Enzymatic activity was measured in the isogenic strains P40-1B, the ure2 mutant P40-3C, and the P40-3C strain transformed with the pIC-CS plasmid carrying the URE2 gene. The assays were performed using midlog and stationary phase cells and nitrogen-starved cells from these growth phases. During exponential growth, the level of invertase in both wild-type and ure2 mutant cells was comparable. However, the invertase activity in ure2 mutant cells from stationary phase was sixfold lower than in the wild-type cells. When P40-3C cells were transformed with the pIC-CS plasmid, the wild-type phenotype was restored. On nitrogen starvation in the presence of sucrose, the invertase activity in wild-type cells from midlog phase decreased three times, whereas in stationary cells, the activity decreased eight times. However, invertase activity doubled in ure2 mutant cells from both phases. When these cells were transformed with the aforementioned plasmid, the wild-type phenotype was restored, although a significant invertase decrease in stationary cell was not observed. These results suggested that the URE2 protein plays a role in invertase activity.
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PMID:Nitrogen regulation of Saccharomyces cerevisiae invertase. Role of the URE2 gene. 1084 93