V Garay-Flores Rocio, P Segura-Ceniceros Elda, De León-Gámez Rosalba, Balvantín-García Cecilia, L Martínez-Hernández José, Betancourt-Galindo Rebeca, Rosa Paredes Ramírez Alma, Noé Aguilar Cristóbal, Ilyina Anna
Coahuila Autonomous University, Nanobioscience Group of Chemistry Faculty and Medical School.
J Gen Appl Microbiol. 2014;60(6):262-9. doi: 10.2323/jgam.60.262.
The production of glucose oxidase (GOX) and catalase (CAT) by submerged fermentation of the free and immobilized xerophytic fungus Aspergillus niger under equal conditions was compared. To immobilize fungal spores, entrapment in PVA/alginate beads treated with NaNO3/CaCl2 was performed. The yield of immobilization in the beads with a diameter less than 1mm was equal to 100%. Fungus growth and substrate consumption were evaluated in both fermentation systems, demonstrating the lag-period presence in the case of the first cycle of immobilized fungus use. The enzyme production by immobilized fungus reuse was carried out. In these cases, greater enzymatic GOX activity was detected, while CAT activity decreased. SEM micrographs for the beads with immobilized fungus applied in the first and second fermentation cycles were obtained, presenting fungus spreading inside the sphere, spore presence and branching hyphae. Immobilization of A. niger on PVA/alginate beads is effective for GOX and CAT production at least on 2-3 repeated fermentative cycles. Thus, immobilization enables repeated use of microbial cells.
比较了在相同条件下，游离和固定化的旱生真菌黑曲霉通过深层发酵生产葡萄糖氧化酶（GOX）和过氧化氢酶（CAT）的情况。为了固定真菌孢子，采用用NaNO3/CaCl2处理的PVA/海藻酸盐珠粒进行包埋。直径小于1mm的珠粒中的固定化产率等于100%。在两种发酵系统中评估了真菌生长和底物消耗情况，结果表明在首次使用固定化真菌的循环中存在滞后期。进行了固定化真菌重复使用的酶生产。在这些情况下，检测到更高的GOX酶活性，而CAT活性下降。获得了在第一个和第二个发酵循环中应用的固定化真菌珠粒的扫描电子显微镜图像，显示真菌在球体内扩散、孢子存在和分支菌丝。将黑曲霉固定在PVA/海藻酸盐珠粒上至少在2 - 3个重复发酵循环中对GOX和CAT的生产是有效的。因此，固定化能够使微生物细胞重复使用。
