Localization of cellobiose dehydrogenase in cellulose-grown cultures of Phanerochaete chrysosporium
Localization of cellobiose dehydrogenase in cellulose-grown cultures of Phanerochaete chrysosporium
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DOI：
10.1006/fgbi.1996.0954
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发表时间：
1997-04-01
影响因子：
3
通讯作者：
Eriksson, KEL
中科院分区：
文献类型：
--
作者：
Igarashi, K;Samejima, M;Eriksson, KEL
为了阐明纤维二糖酶脱氢酶 (CDH) 在黄孢原毛平革菌 (Phanerochaete chrysosporium) 纤维素降解中的功能，对 CDH 的产生和定位进行了研究，并与在纤维素上生长的振荡和通气静态培养物中的情况进行比较。孵育 8 天后，在摇动培养物的培养基中检测到大量 CDH 活性，而在孵育期间的任何时间点，在静态培养物的培养基中均未检测到 CDH 活性。光学显微镜清楚地表明，静态培养时，许多纤维素颗粒吸附在菌丝表面，而振荡培养时，菌丝表面没有纤维素颗粒吸附。在静态培养物中添加昆布酶对于将纤维素酶颗粒从菌丝表面分离非常有效。使用氧化还原电位电极进行的电位测定，可以在静态培养物中的菌丝/纤维素复合物上检测到一些 CDH 活性。因此，CDH也在静态培养物中产生，尽管其量低于摇动培养物中的量，但该酶不释放到培养基中。 β-1,3-葡聚糖层似乎在 CDH 定位和纤维素降解中发挥重要作用。静态培养物的免疫细胞化学共焦激光扫描显微镜表明，大多数 GDH 吸附在纤维素表面，特别是在培养过程中纤维素酶作用形成的裂纹周围。从这些观察中，我们得出结论，CDH 与纤维素酶合作直接参与纤维素的降解。 (C) 1997 年学术出版社。
To elucidate the function of cellobiase dehydrogenase (CDH) in cellulose degradation by Phanerochaete chrysosporium, production and localization of CDH were investigated and compared with those in shaking and aerated static cultures grown on cellulose. Substantial CDH activity was detected in the medium of the shake cultures after 8 days of incubation, while no CDH activity was detected in the medium of static cultures at any point during the incubation period. Light microscopy clearly showed that many cellulose particles were adsorbed on the surface of the hypha in static cultures, whereas no cellulose particles were adsorbed to the hypha in shake cultures. The addition of laminarinase to static cultures was very effective in detaching cellulase particles from the hypha surfaces. Using a potentiometric assay performed with an oxidation-reduction potential electrode, some CDH activity could be detected on the hypha/cellulose complexes in static cultures. Thus, CDH is produced also in static cultures, albeit in lower amounts than in shake cultures, but tt-le enzyme is not released into the medium. It seems likely that the beta-1,3-glucan layer plays an important role in CDH localization and cellulose degradation. Immunocytochemical confocal laser scanning microscopy for the static cultures demonstrated that most GDH was adsorbed on the surface of the cellulose, especially around the cracks, which were formed by the action of cellulases during the course of incubation. From these observations, we conclude a direct participation of CDH in the degradation of cellulose in cooperation with cellulases. (C) 1997 Academic Press.