Kwak M Y, Rhee J S
Department of Biotechnology, Korea Advanced Institute of Science and Technology, Taejon.
Appl Microbiol Biotechnol. 1992 Feb;36(5):578-83. doi: 10.1007/BF00183232.
Conidia of Aspergillus oryzae were immobilized in Ca-alginate beads and then incubated in a nutrient medium to yield an immobilized biocatalyst producing kojic acid. The immobilized cell cultures produced kojic acid linearly during cultivation. Regardless of the size of the immobilized particles, there existed an optimal nitrogen concentration for the maximum production rate of kojic acid, at which smaller bead sizes resulted in a higher production rate. When the growth of mycelia were confined within the bead surface and segregated from each other by gel material, they produced kojic acid with maximal catalytic activity and exhibited the highest conversion yield of glucose. The extent of mycelial segregation was especially higher in cultures of smaller bead particles, and the depth of mycelial growth was 150 to 250 microns from the gel bead surface in all cultures of different nitrogen concentrations and bead sizes. Therefore, for the maximum expression of catalytic activities of immobilized mycelial cultures, it was found very critical to optimally control the mycelial distribution in gel beads by the culture conditions affecting mycelial growth.
米曲霉分生孢子被固定在海藻酸钙珠中，然后在营养培养基中培养，以产生固定化的生产曲酸的生物催化剂。固定化细胞培养物在培养过程中线性产生曲酸。无论固定化颗粒的大小如何，对于曲酸的最大生产率都存在一个最佳氮浓度，在该浓度下，较小的珠粒尺寸导致更高的生产率。当菌丝体的生长被限制在珠粒表面并被凝胶材料彼此分隔开时，它们产生具有最大催化活性的曲酸，并表现出最高的葡萄糖转化率。在较小珠粒颗粒的培养物中，菌丝体的分隔程度尤其更高，并且在所有不同氮浓度和珠粒尺寸的培养物中，菌丝体生长的深度距离凝胶珠表面为150至250微米。因此，为了使固定化菌丝体培养物的催化活性得到最大表达，发现通过影响菌丝体生长的培养条件来最佳地控制凝胶珠中菌丝体的分布非常关键。
