Recuperação e purificação parcial de proteases colagenolíticas de tainha (Mugil liza) usando precipitação e particionamento em sistemas de fases

Abstract

Proteases play an important role in the field of biotechnology studies, which is why the research for alternative sources is highly desirable. Thus, combining extraction, recovery and purification techniques to alternative sources, such as by-products of the fishery production chain, in order to generate the least possible damage to the aquatic environment is profitable for the global enzyme market. Therefore, the objective of the present work is to partially recover and purify collagenolytic proteases from Mullet (Mugil liza) digestive viscera with potential biotechnological application. For this, the digestive viscera extract (intestine, liverand a mixture of various viscera) was precipitated using ammonium sulfate ((NH4) 2SO4). In addition, the intestinal viscera were submitted to partitioning by an Aqueous Two-Phase System (ATPS) and a Three-Phase Partitioning system (TPP), to evaluate the most beneficial conditions for the purification of collagenolytic proteases. The results obtained demonstrate that, for ammonium sulphate precipitation, the best results of Purification Factor occurred in concentrations of 30-60% for all assessed extracts (intestine, liver and mix); the aqueous two-phase system (PEG/Citrate) carried out with Mullet intestinal viscera extract demonstrates that the conditions: PEG of 8000 g/mol molar mass; 20% concentration of PEG; 15% citrate concentration lead to the highest purification factor. It is also observed that the collagenases tend to migrate to the PEG-rich phase; for the three-phase system (t-butanol / (NH4) 2SO4) the highest recovery rate of collagenolytic protease was observed in the proportion of 1:0.5, obtaining recovery of 240.01% and a purification factorof 2,55. Thus, it is concluded that the tests can be used in the recovery of biomolecules from neglected organic solid waste from the fishing industry.