Carangoides bartholomaei (Cuvier, 1833) stomach: a source of aspartic proteases for industrial and biotechnological applications.

M K S Silva,M L E Leal,R S Bezerra,L D A Costa,A C V Freitas-Júnior,T A Silva,H M S Costa,J A F Silva

doi:10.1590/1519-6984.234413

Abstract

The viscera and other residues from fish processing are commonly discarded by the fishing industry. These by-products can be a source of digestive enzymes with industrial and biotechnological potential. In this study, we aimed at the extraction, characterization, and application of acidic proteases from the stomach of Carangoides bartholomaei (Cuvier, 1833). A crude extract from the stomachs was obtained and submitted to a partial purification process by salting-out, which obtained a Purified Extract (PE) with a specific proteolytic activity of 54.0 U⋅mg-1. A purification of 1.9 fold and a yield of 41% were obtained. The PE presents two isoforms of acidic proteases and a maximum proteolytic activity at 45 °C and pH 2.0. The PE acidic proteolytic activity was stable in the pH range of 1.5 to 7.0 and temperature from 25 °C to 50 °C. Purified Extract kept 35% of its proteolytic activity at the presence of NaCl 15% (m/v) but was totally inhibited by pepstatin A. Purified Extract aspartic proteases presented high activity in the presence of heavy metals such as Cd2+, Hg2+, Pb2+, Al3+, and Cu2+. The utilization of PE as an enzymatic addictive in the collagen extraction from Nile tilapia scales has doubled the process yield. The results indicate the potential of these aspartic proteases for industrial and biotechnological applications.

Highlights

Fish are foods that need some processing, because they are very perishable, and because it is required by modern consumers
The viscera of C. bartholomaei and the skins with scales of O. niloticus were donated by fishmongers in the metropolitan region of the João Pessoa city, Paraíba, and taken to Laboratório de Biomoléculas de Organismos Aquáticos (BiOAQUA) from the Universidade Federal da Paraíba, where the stomachs and scales were separated, weighed and stored at -20 °C
Crude extract obtained from C. bartholomaei stomach showed specific activity of 54.0 U·mg-1

Summary

Introduction

Fish are foods that need some processing, because they are very perishable, and because it is required by modern consumers. The large national production of fish, when processed, generates thousands of tons of by-products. The C. bartholomaei, popularly known as yellow jack or guarajuba, lives in small groups, in subtropical and temperate marine waters. This species belongs to the family Carangidae and plays important ecological and economic roles (Duarte et al, 2017). According to the latest data published by the Brazilian government, the C. bartholomaei national production was approximately 1,649 t in the year 2011 (Brasil, 2011)

Objectives

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Results