Otimização da produção de pectinases fúngicas via fermentação submersa

Abstract

Microbial enzymes are biological catalysts used to accelerate the reaction velocity of several industrial processes. The biological enzymes market has grown a lot, therefore, to keep up this progress the development of new enzymes and its study for new fields of biotechnological application is indispensable. Pectin liases are able to catalyze the pectin molecule without changing the specific aroma of the product and producing toxic methano. Thus, they are the target of studies for applications in the sector of the food and beverage. In this context, the present study aims to evaluate the potential of pectinase production by three filamentous fungi: Aspergillus niger, Cladosporium cladosporioides and Trichoderma viride via submerged fermentation, aiming producing an enzyme concentrate with pectin lyase activity to be studied in food and beverage processing. The rotational central composite design (RCCD) was used to optimize the production of pectinases by the three fungi. From the response surface methodology it was observed that the ideal fermentation conditions for maximum production of pectin lyase (PL) and polygalacturonases (PG) are different among the evaluated fungi. The differences in PL and PG activity due to the influence of temperature were observed. High PL activity is associated with temperatures between 25 and 30 ºC and high exo-polygalacturonase (Exo- PG) activity associated with temperatures close to 35 ºC. Here it was shown that C. cladosporioides has the potential to produce pectinases, being the first report about the high pectin lyase activity produced by it in submerged fermentation. The fermentation conditions optimized for C. cladosporioides to produce high levels of pectin lyase activity (76 U/g) in the fermented extract were at 120 hours of fermentation, initial pH 4.5 and at 25 ºC with 5 g/L of citrus pectin. Thus, we suggest C. cladosporioides C196 as a source of new PL enzymes, which may be studied in food and beverage processing.