(582du) Evaluation of the Influence of pH and Temperature On Enzymatic Activity of Alfa-Acetolatato Decarboxylase | AIChE

(582du) Evaluation of the Influence of pH and Temperature On Enzymatic Activity of Alfa-Acetolatato Decarboxylase

Authors 

Gonçalves, L. R. B. - Presenter, Universidade Federal do Ceará
Lemos, C. M., Universidade Federal do Ceará
França, Í. W. L. Sr., Universidade Federal do Ceará



During beer production process, the main fermentation products are ethanol and carbon dioxide, but also other products are obtained at a lower amount. An important carbonyl compound produced in the fermentation and present in the beer is the diacetyl, since it causes an undesirable organoleptic characteristic to the product, which is  the flavor of butter. Efficient control of diacetyl concentration can be achieved with strategies for the prevention of the formation of the precursor (α-acetolactate) or by increasing the rate of chemical decarboxylation of it. The use of the enzyme a - acetolactate decarboxylase has been proposed to overcome the formation of diacetyl converting a - acetolactate directly into acetoin. The use of a - acetolactate decarboxylase makes it possible to shorten primary fermentation of beer and even decrease the maturation time with respect to the amounts of diacetyl. The objective of this work is to analyze the effects of pH and temperature on the enzymatic activity of a - acetolactate decarboxylase from Bacillus subtilis. The reaction medium used for evaluation of thermal and pH stability was composed of MES buffer at a concentration of 0.05 mM. The temperatures tested were 10 ºC, 20 ºC, 30 ºC, 40 ºC and 50 ºC and the pHs were 4.5, 5.5, 6.5, 7.5 and 8.5.The enzyme (soluble or immobilized) was retained at each temperature and pH condition for 60 minutes. The temperature and pH values were chosen based on studies of the enzyme a - acetolactate decarboxylase derived from other microorganisms.