Digestive Proteases From Fish Processing Wastes: Their Partial Characterization and Comparison

Fish processing generates a lot of wastes which are discarded resulting in environmental problems. However, this material represents a significant source of high-value bioproducts with potential biotechnological applications. The objective of this study was to characterize and to compare specific activities of acid and alkaline proteases recovered from the viscera of Merluccius hubbsi (Mh), Percophis brasiliensis (Pb), Urophyis brasiliensis (Ub), and Cynoscion guatucupa (Cg) under different pH and temperature conditions. Stomach proteinases from four species had a higher activity at pH 2, with stability in the range of pH 2-4. Optimum pH from intestinal enzymes of Cg was 11.5, while for the crude extract of Mh, Pb, and Ub catalytic activity was registered over a wide pH range range from 7 to 11.5. Stomach proteinases from four studied species had a higher activity at 30 °C and 50 °C, with stability at 10 °C and 30 °C. Optimum temperature from intestinal enzymes of the four tested species was 50 °C with high stability at 10 °C and 30 °C. Alkaline proteinase from all species and acid proteinases from Cg was inactivated at 70ºC, while stomach enzymes of Mh, Pb, and Ub had a residual activity lower than 5% at 80 °C after 5, 10 y 20 minutes of pre-incubation, respectively. Digestive proteinases recovered in this study could be used as biocatalysts in industrial processes, reducing costs, adding value to the fishery waste, and contributing to the reduction of environmental pollution.

Morphofunctional change small intestine in patients with ulcer disease

The current course of diseases of the digestive system is characterized by a multi-system pathology. The long-term existence of isolated diseases of the organs of the gastrointestinal tract is impossible: the pathology of some organs of a single functional system affects the development of the pathology of other organs.Purpose. To study the features of intestinal digestion in patients with peptic ulcer.Material and methods. 152 patients with peptic ulcer who were hospitalized in the gastroenterological department of Mordovian Republican Clinical Hospital were examined in 2011–2017. The main indicators of intestinal digestion by the activity of intestinal enzymes were studied.Results. Symptoms of impaired intestinal function are observed in 47 % of patients with peptic ulcer disease. In their development, a violation of membrane hydrolytic processes, which were expressed as a decrease (p < 0.05) in the activity of the main intestinal enzymes of maltase in 74 %, alanine aminopeptidase – 73 %, alkaline phosphatase – 62 %, glycyl-L-leucindipeptidase and protein – 37 % (p < 0.01).Conclusions. With peptic ulcer, the processes of membrane intestinal digestion are disrupted, which contributes to the development of clinical symptoms of a violation of the basic functions of the small intestine.

Duplications and Functional Convergence of Intestinal Carbohydrate-Digesting Enzymes

Vertebrate diets and digestive physiologies vary tremendously. Although the contribution of ecological and behavioral features to such diversity is well documented, the roles and identities of individual intestinal enzymes shaping digestive traits remain largely unexplored. Here, we show that the sucrase-isomaltase (SI)/maltase-glucoamylase (MGAM) dual enzyme system long assumed to be the conserved disaccharide and starch digestion framework in all vertebrates is absent in many lineages. Our analyses indicate that independent duplications of an ancestral SI gave rise to the mammalian-specific MGAM, as well as to other duplicates in fish and birds. Strikingly, the duplicated avian enzyme exhibits similar activities to MGAM, revealing an unexpected case of functional convergence. Our results highlight digestive enzyme variation as a key uncharacterized component of dietary diversity in vertebrates.

The Physiology and Biochemistry of the Digestion System of Termites from the Genus Anacanthotermes Jacobson, 1904

A variety of morphological and functional features of the digestive system of termites is associated with their nutritional adaptation. Wood is mostly the food of termites&rsquo; adult larvae, workers and young nymphs. The salivary and intestinal enzymes play an important part in this process. The physiology and biochemistry of the digestion system of termites from the genus Anacanthotermes is still not fully studied. In the present research, we studied the activity of some carbohydrases in termites&rsquo; salivary glands. Our data show that the activity of exocellulase in adult termites is 1.5 times more that in young individuals and 3 times more active than in nymphs, while the exocellulase in soldiers remains inactive. Moreover, the activity of celluloses in the intestine of A. turkestanicus is still not fully studied. We observed that exocellulase is involved in the digestion of food polymers in the castes of termites-workers, nymphs and soldiers. Thus, cellulase activity in the intestinal tissue (intrinsic) is manifested at a very low level in all termites&rsquo; castes we studied. However, the activity of exocellulase in the intestinal cavity (symbiotic) increases 3.5 times in workers, 3.0 times in nymphs and 2.4 times in soldiers compared to that in intestinal tissue. In addition, the intrinsic activity of this enzyme differed little in all three castes of termites, whereas the symbiotic activity in workers and nymphs was more showed than in soldiers.

Investigation of Intestinal Enzyme Activity and Effects of Non-starch Polysaccharide on it

This experiment investigates the effects of utilizing Rahnama cultivar with high non-starchy polysaccharide content and supplementation of xylanase enzyme in poultry feed on the productivity features, nutrient digestibility and intestinal enzymes activity of 21-47 week laying hens. The experiment was conducted quite randomly and in factorial design that included eight treatments with 4 wheat levels (zero, 23, 46 and 69% that contained 1.8, 2.0, 2.2, 2.4% of xylose respectively) and two level enzymes (with and without enzyme) and 5 replications (6 hens) in each replication. During the experiment, by xylose level increase in diet, the weight (p>0.05) and mass of the egg (p>0.01) decreased and feed conversion ratio increased (p>0.05) but there was no effect on feed consumption and egg production rate. Diet supplementation with xylanase resulted in egg production increase (p>0.05), weight and mass increase of eggs (p>0.01) and improved feed conversion ratio (p>0.01). Xylose levels increase resulted in decrease in fat and metabolic energy digestibility of the diet (p>0.05); and, amylase enzymes activity in duodenum and amino peptidase, and lipase in duodenum and jejunum (p>0.01) increased. However, xylanase supplement had no effect on any intestinal enzymes. Diet supplementation with xylanase decreased viscosity of ileum (p>0.01). Increased xylanase level in diet resulted in decreased productivity features of laying hens, increased intestinal enzyme activity and decreased fat and metabolic energy digestibility.