Efeito da temperatura e agitação na degradação de farinha de penas por fungos filamentosos da restinga de Guabim-BA

Abstract

Biotechnology is one of the most used techniques to reduce waste generated by agro-industries, through microorganisms and their enzymatic production. In the poultry industry, the main by-products are viscera, feathers, blood and fat. Feathers are a by-product rich in keratinous protein, rich in amino acids, which can be used as a protein supplement for the production of animal feed. However, due to its low digestibility, the absorption of amino acids is compromised. However, through fermentation processes it is possible to make use of agro-industrial residues, such as feather flour, for the synthesis of various compounds of industrial interest and high added value. The submerged fermentation technique takes place in an aqueous medium and usually with soluble substrates, allowing greater control of physical-chemical parameters such as temperature, aeration, agitation, pH, among others. The use of this technology ends up reducing the environmental cost caused by the existing by-products in agribusiness production. The objective of this work was to evaluate the influence of agitation and temperature on the rate of degradation of feather meal by filamentous fungi Aspergillus terrus Is 37 and Cladosporium sp. ISD8 in submerged fermentation process, as well as evaluating the final pH. The results showed that both temperature and agitation influenced the feather meal degradation rate for both isolates. Regarding agitation, there was a higher degradation rate at 200 rpm for both A. terreus Is 37 and Cladosporium sp. ISD8, with degradation rate above 80% and above 60%, respectively. The best temperature for both isolates was 30 oC, with a statistically significant drop for both isolates at 25 oC and 35 oC. Isolate A. terreus IS37 presented a higher rate of degradation of feather meal than isolate Cladosporium sp ISD8 in all parameters studied. After the end of fermentation, the supernatant showed an alkaline pH, indicating that the degradation of the feather meal proteins had occurred. In general, it can be concluded that fungi were efficient in the degradation of feather meal.