Neurospora crassa를 이용한 Tyrosinase 생산의 최적화

Optimization of Tyrosinase Production using Neurospora crassa

Neurospora crassa는 성장이 끝나고 분화되는 과정에서 tyrosinase를 생산하며 아미노산류의 기질유사체, 반대사물질, 단백질 생합성 저해제 등에 의해 효소생산이 유도된다. 미생물 균체를 배양시키며 여러가지 유도물질을 사용하여 효소의 생합성을 유도시킨 결과 가장 적합한 유도물질은 cycloheximide였다. 이는 균체의 성장을 크게 저해하는 항생제의 일종이므로 효소 생합성을 최대화시키기 위한 최적의 농도가 존재하였으며, 유도물질의 농도가 일정한 경우에 효소 생산에 최적인 유도시간이 존재하였다.

Neurospora crassa (KCTC 6079) produces tyrosinase (EC 1.14.18.1) during sexual differentiation under derepressed conditions in the presence of inducers such as amino acid analogues, antimetabolites or protein synthesis inhibitors. The selection of inducer concentration and induction time as well as inducer type are critical for the optimization of the enzyme production. The best inducer was found to be cycloheximide. Since cycloheximide was toxic to the cells, an optimal inducer concentration and an optimal induction time were determined to maximize the enzyme production from batch cultures. Mathematical models for the cell growth and the enzyme production were proposed and used for process optimization. By optimizing the induction conditions, maximum tyrosinase productivity was increased significantly.