Partitioning of digestive extracts from endemic fishes species of Parana-Paraguay Basin on PEG-citrate aqueous two phase systems

GÓMEZ, GABRIELA N; LAURA C. LEIVA; ACEVEDO GOMEZ, ANTONELLA V; MEDINA, DAIANA; NERLI, BIBIANA B; ANDREA C. VAN DE VELDE; BUSTILLO, SOLEDAD

Guarujá

Conferencia; BPP 2019 BIOPARTITIONING AND PURIFICATION CONFERENCE; 2019

Brazilian Society of Microbiology - USP and UNESP

Fish viscera constitute about 5?8% of visceral mass and are usually discarded as a waste. Theseunwanted materials contain proteases (e.g. trypsin) which have an enormous field of industrialapplications. Although proteases from various sources have been studied extensively, those of fishhave not been fully explored. Polymer/salt aqueous two-phase systems (ATPSs) provide a powerfulmethod for separating biomaterials. Those ATPSs containing biodegradable anions such as citrate areinteresting due to their eco-friendly character. The aim of this work was to evaluate viscera extracts ofthree endemic fish species from Parana-Paraguay basin as potential sources of proteases. In addition,their partitioning properties in ATPSs formed by polyetilenglycol MW 3,350 (PEG3350) and sodiumcitrate (NaCit), pH 5.0 and pH 8.0, were explored in order to design an extraction strategy. Extractsfrom pancreatic diffuse tissue, such as pyloric cecae of palometa (Pygocentrus nattereri, a carnivorousfish) and pacú (Piaractus mesopotamicus, omnivorous) and mesentery of surubi (Pseudoplatystomacorruscans, carnivorous) named Pne, Pme and Pce, respectively, were assessed. Total protein (TP),trypsin-like activity (Tryp) and total protease content (Pase) were determined in the extracts and in thephases after partitioning equilibrium. TP of viscera extracts was similar for all species, ranging 0,5-0,6mg/mL, but Pase and Tryp content showed marked differences between carnivorous (high values) andomnivorous (low value) species. Additionally, Pce exhibit the highest Pase and Tryp activities,probably due to its tissue source (mesentery). Partitioning equilibrium for Tryp was displaced to the topphase in practically all the ATPSs explored. The highest partition coefficient (Kp,Tryp) was observed forthe Pce while the lowest values were obtained for the Pme. Distribution of Pase followed a similartrend to Tryp, exhibiting a higher affinity for the polymer-enriched phase but less one-sided. However,a different behavior was observed when TP partitioning was analyzed, since the Kp,TP values resultedclose to the unity (0.98-1.68). The selectivity parameter  (Kp,Tryp/Kp,TP or Kp,Pase/Kp,TP), which isrepresentative of the ATPSs ability to separate proteases from other proteins present, showed valueshighly far from unity, particularly for Pce and Pne. Thus, our results suggest that PEG3350/NaCitATPS constitute a potential tool at primary recovering of proteases from fish wastes.