Bactérias celulolíticas e o uso de resíduo de maracujá (Passiflora edulis) em rações extrusadas para juvenis de tambaqui (Colossoma macropomum)

Abstract

Tambaqui cultivation is an economic activity in a phase of expansion in the Amazonian Region. However, the high costs associated with feed somewhat reduce the activity s growth, leading the producer to use feed inappropriate for this specie s nutritional requirements. Consequently, research is required concerning the use of vegetables in tambaqui feed. This present study, divided into three phases, used passion fruit seed meal (PFSM) as an alternative food, due to the constitution of its fibrous components and the ability of fibrolytic enzyme-producing bacteria to break it down. In the first phase, fish were collected from the river and from the tanks with the objective of determining the presence of cellulose-producing bacteria and of quantifying cellulose and xylanase. In the second phase, increasing amounts of passion fruit seed meal were incorporated into the feed and tested for digestibility in juvenile fish (0, 10, 20 and 30% PFSM). In the third phase, 30% PFSM feed was used as a substract for inoculation in increasing densities of a cellulose and xylanase-producing bacteria strain, which was given to tambaqui, evaluating the digestibility, production performance variables and body composition. Results from the first phase demonstrated that cellulose-producing bacteria exist in tambaqui intestines and that the TR9 strain produced greater values of endo-b-glucanase, exo-b-glucanase and xylanase. Results from the second phase demonstrated that the incorporation of a 10% amount of PFSM did not affect the feed digestibility and that other percentage levels showed the PFSM s potential as an alternative ingredient. Results from the third phase reveal that the TR9 strain employed did not have any influence on the digestibility, zootechnic performance or body composition of the fish.