Seleção de proteases bacterianas para a remoção das escamas do Colossoma macropomum (Cuvier, 1818) de piscicultura da região amazônica

Abstract

The tambaqui Colossoma macropomum belongs to the family Serrasalmidae could reach more than 1m of total length. It has high commercial value and it is very appreciated by the population of the Amazonian. It is created in an intensive and extensive way. In the Amazonian area your skin used for the transformation in leather could be used in the making of bags, shoes and belts. The objective of the present work was to test the use of enzymatic crude extract bacterial in the degradation of the obtained collagen of the skin of the tambaqui being verified sweats efficiency during the tanning of the skin. For so much the study began for the isolation of the proteolitic bacterial microbiota from the digestive tract of the tambaqui. Later it was extracted the gelatin of the skin of the tambaqui being determined their physicochemical characteristics. A selection was accomplished by the enzymatic activity being tested the potential of degradation of the gelatin parallel with agar gelatin milk prepared with commercial gelatin and the same agar prepared with gelatin obtained starting from the skin of the tambaqui. They were chosen the isolated ones with the largest inhibition halos obtained with agar gelatin milk prepared with commercial gelatin. Later it was identified the isolated with larger proteolític and colagenolitic activity of the Chryseomonas luteola. With the crude extract of the bacteria C. luteola the studies were developed for the characterization of the proteases and determination of the effect of the crude extract in the stage of the removal of scales during the preparatory phase for the tanning. In the study of the characterization of the proteases it was verified that the protease of the crude extract obtained pH and temperature great of 7.2 and 70ºC to 80ºC. The relative activity was 117% respectively, while the residual activity to 70°C was of 166% suffering a reduction in 80°C for 26% for 90 minutes of incubation. It was verified the effect of the time and agitation in the treatment of the fragments of tambaqui skin for the crude extract tested to 25°C in the times of 1 hour, 2 hour and 3 hours. The results indicated that there was significant difference as for the agitation condition (p=0.000) and time of incubation (p=0.001) being opted for the treatment without agitation due to the type of system of used tanning to be, without agitation, and the time of 1 hour for having the largest value of enzymatic activity of the crude extract. Sensorial evaluation accomplished in the fragments of tambaqui skin in 1hour indicated that 83.33 % of the judges considered the flexible skin fragments when removing the scale with the spoon in the treatment without agitation. In the effect of the enzymatic crude extract of C. luteola produced to 40ºC and tested 25ºC in fragments of tambaqui skin was chosen the treatment (1:10), of crude extract and distilled water, and the sensorial analyses indicated that 67 % of the judges attributed the note D and 33.33 % the note B. The histological analyses indicated that the crude extract in the treatment (1:10) it produced alterations in the architecture of the fibers similar collagens those alterations produced by the papain to 0.02 %. And it was verified that the prepared crude extract in the treatment (1:10) on the whole skins it removed with certain easiness the scales of the skin in 1 hour of exhibition and with easiness in 2 hours of exhibition.