pH Characterization of Digestive Enzyme and In vitro Digestibility of Red Bee Shrimp Caridina cantonensis (Decapoda: Atyidae) (original) (raw)
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Techniques for protein digestion research in Decapoda: A review
Trends in Food Science & Technology, 2019
Background Decapods belong to Pancrustacea, all are of ecological and economic importance since many species are profitable either harvested in the wild or produced in aquafarming. The description of biochemical physiology is paramount for both, ecology and economy. Being protein the most expensive ingredient in fabricated feeds, explaining food protein digestion is a chief step in understanding nutrition. Scope and approach The review deals with techniques used for the study of peptidases, enzymes hydrolyzing peptide bonds in proteins, with an emphasis in the study of food protein digestion in decapods. Key Findings and Conclusions Such techniques have shown what, who, and where peptidases are and the importance of proteins in nutrition and hence in protein digestion. The methods used in the research of digestive peptidases in decapods are enlisted and some remarks are given, such techniques can be applied in other Crustacea and even Insecta species yet to be studied and decodified.
Evaluation of In Vitro Apparent Protein Digestibility by Shrimp Using Gut Enzyme Extracts
Journal of the World Aquaculture …, 2009
Knowledge of apparent protein digestibility (APD) is required for optimization of feed formulae for the production of marine penaeid shrimp. The purpose of this study was to evaluate an in vitro method for determining APD in marine penaeid shrimp using gut enzyme extracts. A high correlation (r 2 5 0.95) was shown between single-ingredient APD values for fish meal diets using in vivo methodology and those derived from in vitro testing of ingredients. A second study showed positive correlation (r 2 5 0.71) between in vitro APD of selected purified and semipurified ingredients and their reported in vivo APDs. This correlation was much higher for purified ingredients (r 2 5 0.93) versus less-refined ingredients (r 2 5 0.24). A third trial compared in vitro APD at three different enzyme extract pH values and showed that for most protein sources, APD was significantly highest (P , 0.05) at pH 5 7.0 and lower at pH 5 6.1 or 7.9, indicating a neutral pH optimum for this methodology.
Journal of the World Aquaculture Society, 1998
I n vitro enzyme assays are rapid, inexpensive techniques for estimating protein digestibility of feed ingredients. Three assays-the Lazo single-enzyme assay with porcine trypsin; the Hsu multi-enzyme assay with porcine trypsin, a-chymotrypsin, and peptidase; and the Satterlee multi-enzyme assay with porcine trypsin, a-chymotrypsin, peptidase, and bacterial protease-were used to estimate relative protein digestibility (RPD) of selected feed ingredients used in diets for the Pacific white shrimp Penueus vannamei. Ingredients tested were casein, gelatin, rice bran, shrimp meal, soybean meal, wheat gluten, and six varieties of fish meal. A highly significant, inverse, linear relationship existed between final pH in each of the enzyme 0
Aquaculture, 2004
The effect of change in feed and physical manipulation on the digestive system of white shrimp Penaeus vannamei (Boone, 1931) was examined for proteases secreted by the digestive gland and excreted in feces. Organisms were fed a commercial feed containing 45% protein and separated into two groups. One group served as the control and the other was physically manipulated weekly. Each group was subdivided into two groups, establishing four experimental subgroups, 50% of the organisms in each group used as controls and the others subjected to a change in feed by shifting from a 45% protein feed to a 35% protein feed from different brands to induce alimentary stress. Organisms were individually maintained and feces collected and analyzed on a daily basis for 2 months. Trypsin and chymotrypsin activities decreased in feces and mid-gut gland extracts of organisms fed the 35% protein feed and those physically manipulated during weighting. Two-way ANOVA demonstrated a greater effect of physical manipulation on trypsin and chymotrypsin activities than change in feed. One-way ANOVA demonstrated differences between the two periods analyzed (before and after the beginning of stressors). Composition of proteases in the mid-gut gland and feces were identical, as observed by S-SDS PAGE. Studies of enzyme activities in feces may be helpful, when studying organisms of short digestion periods where very active enzymes and lowefficiency digestion are expected, as in the case of decapods. D
Aquaculture Research, 2009
Proteases from the midgut gland of the Farfantepenaeus paulensis juveniles were assessed. Enzyme activity was determined using protease substrates and inhibitors. The effect of pH, temperature and calcium on proteolytic activity was assayed. Caseinolytic activity was analysed in substrate-sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Trypsin, chymotrypsin and leucine aminopeptidase activity was detected. Proteolytic activity was strongly inhibited by the specific trypsin inhibitors. Tosyl-phenylalanine chloromethyl ketone inhibited 59.3% of chymotrypsin activity. The greatest trypsin-like activity occurred at pH 8.0 and 45 °C. Chymotrypsin-like activity reached maximal values at alkaline pH (7.2–9.0) and 55 °C. CaCl2 did not increase trypsin-like activity, but rather inhibited it at concentrations of 30 (20%), 50 (30%) and 100 mM (50%). The substrate-SDS-PAGE zymogram revealed eight proteinase bands. Two possibly thermal-resistant (85 °C, 30 min) chymotrypsin isoforms were found, which were inhibited by phenyl-methyl-sulphonyl-fluoride. Aminopeptidase activity of enzyme extracts (Arg, Leu, Lys, Phe and Val) and the recommended concentrations of these essential amino acids in penaeid shrimp diets were positively correlated (P<0.05). Beause protein digestion involves the combined action of different enzymes, adequate knowledge of shrimp digestion and enzyme characteristics is required for the assessment of the digestive potential of different feed sources and development of in vitro digestibility protocols.