beta-Glucuronidase activities of intestinal bacteria determined both in vitro and in vivo in gnotobiotic rats

Abstract

The 0-glucuronidase activities of bacterial strains isolated from the rat intestinal tract were studied both in vitro in culture media and in vivo in the intestinal contents of gnotobiotic rats. Only 50 of 407 strains tested were found to be positive in vitro. They belonged to the three genera Clostridium, Peptostreptococcus, and Staphylococcus. The in vitro-negative strains were also negative in vivo. The I-glucuronidase activities of the positive strains were generally greater in vivo than in vitro. The highest in vivo activities were found in the intact bacterial cells and in the soluble fractions prepared from disrupted pellets. There was a discrepancy between the activities obtained from both conventional and gnotobiotic rats harboring selected positive strains, suggesting that the main 0-glucuronidase-positive strains have not yet been isolated from the intestines of conventional rats. Glucuronidation together with sulfation are the most usual forms of conjugation observed during the metabolism processes in mammals and also represent the major pathway for detoxification mechanisms. Thus, hydrolysis of glucuronides by ,-glucuronidase enzymes have been considered by pathologists to be an important enzyme reaction in the digestive tract. The 3-glucuronidase enzymes were detected both in intestinal tissues and in intestinal bacteria. The activity in the intestinal tissues was found to be optimal at pH 4.5, whereas that of bacteria was best at around pH 6.5 to 7.0 (13). Williams et al. (16) and Rod and Midtvedt (13) clearly

Influence of peroral antibiotics upon the biotransformatory activity of the intestinal microflora in healthy subjects

“…As far as the authors are aware, no studies concerning antibioticrelated alterations in intestinal microbial bilirubin deconjugation have previously been carried out. pglucuronidase enzyme involved has been claimed to be commonly occurring among intestinal microbes [25, 261. Recently, however, Gadelle et al [27] questioned this assumption.…”

Hydrolysis of iodothyronine conjugates by intestinal bacteria

“…In this review, attention is payed to two groups of enzymes, the sulfatases and the glucuronidases, hydrolyzing a wide variety of substrates. Several topics have already been described or reviewed such as bacterial sulfatase activity towards conjugated xenobiotics in the gastrointestinal tract [9], bile acid sulfatases of obligately anaerobic bacteria from the intestinal tract of the rat [10][11][12][13][14][15], and glucuronidase activity of intestinal bacteria acting on different artificial glucuronides [16][17][18].…”

Variations in concentrations of bacterial metabolites, enzyme activities, moisture, pH and bacterial composition between and within individuals in faeces of seven healthy adults

“…However, the enzyme activities reported in this study as well as other faecal properties did not appear to be associated with specific populations of faecal bacteria. Fujisawa and Mori (1992) followed types and numbers of Estherichia coli strains with or without G N activity over a long term in the same volunteers, and found considerable variability in the composition of these strains, indicating that bacterial composition at strain level, as well as at species level, may affect total faecal enzyme activities (Hawksworth et al 1971;Gadelle et al 1985).…”