Exogenous enzymes in aquaculture: Alginate and alginate-bentonite microcapsules for the intestinal delivery of shrimp proteases to Nile tilapia

RODRIGUEZ, YAMILA E.; LAITANO, MARÍA V.; PEREIRA, NAIR A.; LÓPEZ-ZAVALA, ALONSO A.; HARAN, NORA S.; FERNÁNDEZ-GIMENEZ, ANALÍA V.; RODRIGUEZ, YAMILA E.; LAITANO, MARÍA V.; PEREIRA, NAIR A.; LÓPEZ-ZAVALA, ALONSO A.; HARAN, NORA S.; FERNÁNDEZ-GIMENEZ, ANALÍA V.

AQUACULTURE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 490 p. 35 - 43

0044-8486

Shrimp processing waste holds digestive proteases with a great potential to be used as feed supplement for Niletilapia Oreochromis niloticus. In the present work, we characterize both sodium alginate (A) and sodium alginatebentonite(AB) microcapsules to entrap enzymes obtained from Pleoticus muelleri processing waste. Also, weevaluate these encapsulation methods as a strategy to improve intestinal delivery of exogenous enzymes in O.niloticus in order to enhance their digestion process. The effects of different storage methods, in vitro simulationof gastric pH conditions and exposition to 40 °C were studied. In order to evaluate if microencapsulated shrimpenzymes are active when they reach fish gut, animals were exposed to three treatments: (1) fast, (2) diet and, (3)AB capsules+diet. Alginate capsules were more affected by different storage methods than alginate-bentoniteones. SEM images showed a correlation between decreased enzyme activity and capsule microstructure changes.The best method to store the AB beads is at −20 °C. After incubating for 7 h at 40 °C, we observed a notoriousreduction in the enzyme activities of both microcapsules. On the other hand, at pH 3 both microcapsules preventedenzyme irreversible denaturalization and kept 100% of their activity. The overall results indicate that ABcapsules are better vehicles to deliver shrimp enzymes in Nile tilapia. In the bioassay, we observed that when fishwere fed with treatment 3, the alkaline protease activity in their intestines was 27% higher than that of the dietfish group. Thus, encapsulated shrimp enzymes have a great potential to be used as a feed supplement in fishnutrition. Further trials involving grow bioassays are needed to verify if this shrimp enzyme contained in ABcapsules improve fish digestion, feed conversion, body weight and survival rate.