Formation of glycosidases in batch and continuous culture of Bacteroides fragilis

Abstract

Nine strains of Bacteroides fragilis were cultivated in stirred fermentors and tested for their ability to produce glycosidases. B. fragilis subsp. vulgatus B70 was used for optimizing the production of glycosidases. The highest bacterial yield was obtained in proteose peptone-yeast extract medium. The optimum pH for maximal bacterial yield was 7.0, and the optimum temperature for growth was 37°C. The formation of glycosidases was optimal between pH 6.5 and 7.5, and the optimum temperature for synthesis of glycosidases was between 33 and 370C. Culture under controlled conditions in fermentors gave more reproducible production of glycosidases than static cultures in bottles. The strain was also grown in continuous culture at a dilution rate of 0.1 liter/h at pH 7.0 and 370C with a yield of 2.0 mg of dry weight per ml in the complex medium. The formation of glvcosidases remained constant during the entire continuous process.

Hemicellulose‐degrading Enzymes Synthesized by Rumen Bacteria

“…The activities reported here were detected in crude enzyme preparations under standard assay conditions and higher or other activities may have been measured under optimum conditions. Similarly growth conditions (Berg et al 1978) and substrates (Williams & Withers 1981) affect enzyme levels.…”

Arabinogalactan and fructo‐oligosaccharides have a different fermentation profile in the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®)

“…SEC was performed on a superose 12 column, using 50 mM ammonium acetate as eluent with a flow rate of 0.4 ml min -1 . Activity for b-glucosidase, a-galactosidase, b-galactosidase and a-Larabinofuranosidase was measured by means of colorimetric assays as described by Berg et al, (1978).…”

Production and properties of alpha-glucosidase from Lactobacillus acidophilus

“…A similar finding has been reported in Pseudomonas sp. strain SB-15 (24), which is in contrast to the constitutive a-glucosidase reported in Streptococcus pyogenes (6), Streptococcus mitis 903 (17), and Bacteroides fragilis (2).…”

“…The highest level of enzyme production is obtained when both proteose peptone and yeast extract are added to the culture medium. It has been reported that proteose peptone with yeast extract supports the highest yield of oe-glucosidase in B. fragilis (2).…”

“…The enzyme a-glucosidase (a-D-glucoside glucohydrolase; EC 3.2.1.20) has been reported to occur in animals (11), plants (14), molds, yeasts, and fungi (3,23,26,31). Although a number of studies on bacterial a-glucosidases have been carried out (1,2,10,17,24,25,28,30), there is a paucity of information on the a-glucosidase from Lactobacillus sp. (12).…”