Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microbioassays using bacteria or enzymes are increasingly applied to measure chemical toxicity in the environment. Attractive features of these assays may include low cost, rapid response to toxicants, high sample throughput, modest laboratory equipment and space requirements, low sample volume, portability, and reproducible responses. Enzymatic tests rely on measurement of either enzyme activity or enzyme biosynthesis. Dehydrogenases are the enzymes most used in toxicity testing. Assay of dehydrogenase activity is conveniently carried out using oxidoreduction dyes such as tetrazolium salts. Other enzyme activity tests utilize ATPases, esterases, phosphatases, urease, luciferase, beta-galactosidase, protease, amylase, or beta-glucosidase. Recently, the inhibition of enzyme (beta-galactosidase, tryptophanase, alpha-glucosidase) biosynthesis has been explored as a basis for toxicity testing. Enzyme biosynthesis was found to be generally more sensitive to organic chemicals than enzyme activity. Bacterial toxicity tests are based on bioluminescence, motility, growth, viability, ATP, oxygen uptake, nitrification, or heat production. An important aspect of bacterial tests is the permeability of cells to environmental toxicants, particularly organic chemicals of hydrophobic nature. Physical, chemical, and genetic alterations of the outer membrane of E. coli have been found to affect test sensitivity to organic toxicants. Several microbioassays are now commercially available. The names of the assays and their basis are: Microtox (bioluminescence), Polytox (respiration), ECHA Biocide Monitor (dehydrogenase activity), Toxi-Chromotest (enzyme biosynthesis), and MetPAD (enzyme activity). An important feature common to these tests is the provision of standardized cultures of bacteria in freeze-dried form. Two of the more recent applications of microbioassays are in sediment toxicity testing and toxicity reduction evaluation. Sediment pore water may be assayed directly or solvents may be used to extract the toxicants. Some of the solvents used for extraction of organic chemicals are themselves toxic to bacteria (e.g., dichloromethane), requiring exchange with a less toxic solvent (e.g., ethanol, methanol, DMSO). A modification of the Microtox test allows direct assay of solid-phase samples such as sediments. The toxicity reduction evaluation (TRE) must be carried out at wastewater treatment plants whose effluents fail toxicity standards. The TREs require numerous and repeated toxicity assays, thus favoring application of microbioassays. Presently, no single microbioassay can detect all categories of environmental toxicants with equal sensitivity. Therefore, a battery of tests approach is recommended. The differential sensitivity of alternative tests may, in fact, be exploited. Further research is needed to construct strains of genetically engineered microorganisms or isolate microorganisms or enzymes that respond to specific classes of toxicants. These can be combined into batteries appropriate for different environments or test objectives.
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PMID:Bacterial and enzymatic bioassays for toxicity testing in the environment. 150 75

Because of the potential significance of colonic bacteria in colon carcinogenesis, we investigated the effect of pectin of different types on fecal bacterial enzymes (beta-glucuronidase, beta-glucosidase and tryptophanase) at various periods of time after feeding rats with pectin-containing diets during azoxymethane-induced colon carcinogenesis. The diet supplemented with 20% apple pectin or 20% citrus pectin decreased the multiplicity of colon tumors, and the number of tumors was significantly decreased in the group fed apple pectin. The incidence of colon tumors in the apple pectin group was lower than that in the control group. The mean tumor size was similar among the three groups. Apple pectin feeding decreased fecal beta-glucosidase and tryptophanase levels. Furthermore, a significant decrease in the activity of beta-glucuronidase was observed in the apple pectin group during the initiation phase. These findings suggest that the protective effect of pectin on colon carcinogenesis may be dependent on the type of pectin and be related to the decrease of beta-glucuronidase activity in the initiation stage of carcinogenesis.
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PMID:Effects of apple pectin on fecal bacterial enzymes in azoxymethane-induced rat colon carcinogenesis. 762 15

Five hundreds of bifidobacteria were isolated from a healthy Korean and the inhibitory effects of these isolated bacteria on harmful enzymes of human intestinal microflora were examined by cocultivation of the isolated bifidobacteria with E. coli or total human intestinal microflora. In comparison with the results of E. coli or intestinal microflora cultivation, Bifidobacterium breve K-110, B. breve K-111 and B. infantis K-525 effectively inhibited harmful enzymes (beta-glucuronidase and tryptophanase) of E. coli and lowered the pH of the culture media. Also they inhibited the harmful enzymes (beta-glucosidase, beta-glucuronidase, tryptophanase and urease) and ammonia production of intestinal microflora, and lowered pH of the culture media by increasing lactic acid bacteria of intestinal microflora. When these isolated bifidobacteria were administered on mice, fecal harmful enzymes were also inhibited. Among tested bifidobacteria, B. breve K-110 had the highest inhibitory effect of fecal harmful enzymes.
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PMID:Inhibitory effects of Bifidobacterium spp. isolated from a healthy Korean on harmful enzymes of human intestinal microflora. 987 15

The safety assessment of Bifidobacterium longum SPM1205 isolated from healthy Koreans and this strain's inhibitory effects on fecal harmful enzymes of intestinal microflora were investigated. The overall safety of this strain was investigated during a feeding trial. Groups of SD rats were orally administered a test strain or commercial reference strain B. longum 1 x 10(9) CFU/kg body weight/day for four weeks. Throughout this time, their feed intake, water intake and live body weight were monitored. Fecal samples were periodically collected to test harmful enzyme activities of intestinal microflora. At the end of the four-week observation period, samples of blood, liver, spleen, kidney, and gut tissues were collected to determine for hematological parameters and histological differences. The results obtained in this experiment demonstrated that four weeks of consumption of this Bifidobacterium strain had no adverse effects on rat's general health status, blood biochemical parameters or histology. Therefore, it is likely to be safe for human use. Fecal harmful enzymes such as beta-glucosidase, beta-glucuronidase, tryptophanase and urease, were effectively inhibited during the administration of the B. longum SPM1205. These results suggested that this B. longum SPM 1205 could be used for humans as a probiotic strain.
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PMID:Safety assessment of potential lactic acid bacteria Bifidobacterium longum SPM1205 isolated from healthy Koreans. 1641 Jul 64

As the growth factor of lactic acid bacteria, LD (trehalose) was isolated fromLentinus edodes by using silica gel column chromatography. LD induced the growth ofBifidobacteria breve andLactobacillus brevis, which were isolated from human feces. LD selectively induced the growth of lactic acid bacteria among total microflora. When total intestinal microflora were cultured in the medium containing LD, it stimulated the growth of lactic acid bacteria and inhibited harmful enzymes, beta-glucosidase, beta-glucuronidase, and tryptophanase, of intestinal bacteria. LM, which was a monosaccharide fromL. edodes, induced the growth of lactic acid bacteria but it seems to be invaluablein vivo. LH isolated fromL. edodes by Sephadex G-100 column chromatography was not effective for the growth of lactic acid bacteria.
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PMID:Effect ofLentinus edodes on the growth of intestinal lactic acid bacteria. 1898 87