Polysaccharide Degrading Enzymes in Microbial Populations From the Liquid and Solid Fractions of Bovine Rumen Digesta

Abstract

Polysaccharide depolymerase and glycoside hydrolase enzymes involved in the degradation ofplant structural polysaccharides were most active in the adherent particle-associated microorganisms, whereas soluble saccharides were metabolized by the liquid phase and nonadherent populations. The activities were constant confirming the stability of the populations.Key words: Polysaccharidase, glycosidase, particle-associated microorganisms Although the complexity of the microbial populations associated with the particulate material in rumen digesta has been revealed by electron microscopy there is little information available on their metabolic activities. Williams and Strachan (1984) demonstrated that enzymes which degraded plant cell wall structural polysaccharides were higher in the particle-associated populations. In order to assess the constancy of digesta colonization further studies were undertaken to monitor variations in the activities of the degradative enzymes in the liquid phase and particle-associated populations from the bovlne rumen ecosystem.The microbial populations were prepared using the procedures described previously (Wil- Fig. 1 This study confirmed that plant cell wall polysaccharide-degrading enzymes were more active in the particle-associated subpopulations, 30

Distribution of bacteria in the rumen contents of dairy cows given a diet supplemented with soya-bean oil

“…Chemically, SAB and LAB were clearly different, as previously observed by Merry & McAllan (1983) and Bauchart et al (1986). In earlier work, Williams & Strachan (1984) reported a definite difference in the function of these two bacterial populations, the enzymes degrading plant cell-wall polysaccharides being more active in the SAB, and the non-structural soluble saccharides being metabolized more by the LAB.…”

“…It has been fully demonstrated that the distribution of bacterial species is different in the SAB and LAB fractions isolated from rumen contents (Minato et al 1966) and that the chemical composition (Czerkawski, 1976;Merry & McAllan, 1983;Bauchart et al 1986) and the metabolic functions (Latham, 1980;Williams & Strachan, 1984) of these two populations are very distinct. Moreover, the concentrations of SAB in feed particles appear to be controlled by the chemical composition of the diets.…”

A modified in vitro larvae migration inhibition assay using rumen fluid to evaluate Haemonchus contortus viability

“…Each trial was replicated multiple times, using fresh RF that was never collected more than once every 2 d. Chemical (Merry and McAllan, 1983;Legay-Carmier and Bauchart, 1989) and metabolic (Latham, 1980;Williams and Strachan, 1984) differences exist between particle-and liquid-associated bacteria; thus, to dislodge some of the particle-associated bacteria, approximately 150 g of rumen material was also added to each thermos, which was vigorously shaken for 1 min using a wrist shaker (Labline, Melrose Park, IL, USA). The RF was pooled, strained through 4 layers of cheesecloth into per-warmed beakers, and flushed with CO 2 for 45 s to ensure an anaerobic environment.…”

Effect of ciliate protozoa on the activity of polysaccharide‐degrading enzymes and fibre breakdown in the rumen ecosystem

“…The present experiments were undertaken as part of a study to identify factors that affect enzyme formation and activity in the rumen ecosystem (Williams & Strachan 1984b ;Williams et al 1989). Polysaccharide-degrading enzyme activities were monitored in microbial populations from the solids and liquor fractions of protozoa-free ovine rumen contents 2 h and 16 h into the postprandial period.…”