Rodriguez-Couto Susana, Arzac Alejandro, Leal Gracia Patricia, Tomovska Radmila
CEIT, Unit of Environmental Engineering, Paseo Manuel de Lardizábal, Donostia-San Sebastián, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
Biotechnol J. 2014 Apr;9(4):578-84. doi: 10.1002/biot.201300474. Epub 2014 Feb 12.
Fungal immobilization is an interesting topic in enzyme production and bioprocess development. The properties of graphene (i.e. large surface area, hydrophobicity), together with the possibility of producing it at low cost and with tailor-made properties, make this popular material worthy of investigation as a support for fungal immobilization. In the present paper, 3D-organized structures of reduced graphene oxide (rGO) in hydrogels and their dried derivatives (xerogels) were synthesized, characterized and investigated as potential supports for the immobilization of the white-rot fungus Trametes pubescens. It was found that the morphology of the hydrogels and xerogels was not influenced by the synthesis conditions; however the 3D structure was preserved after drying and formation of xerogels. Both, hydrogels and xerogels have been shown to be suitable supports for the immobilization of T. pubescens. Additionally, xerogels promoted increased laccase activities and maximum activity values of about 20 ± 1 U/mL were attained. These activities were much higher than those obtained with other well-known inert supports. Nevertheless, no relationship between support morphology and productivity was found. The encouraging results obtained have paved the way for the development of novel graphene-based supports for microorganism immobilization.
真菌固定化是酶生产和生物工艺开发中一个有趣的课题。石墨烯的特性（即大表面积、疏水性），以及以低成本生产并具有定制特性的可能性，使得这种流行材料作为真菌固定化的载体值得研究。在本文中，合成、表征并研究了水凝胶中还原氧化石墨烯（rGO）的三维组织结构及其干燥衍生物（干凝胶），作为固定化白腐真菌毛栓菌的潜在载体。结果发现，水凝胶和干凝胶的形态不受合成条件的影响；然而，在干燥和形成干凝胶后，三维结构得以保留。水凝胶和干凝胶都已被证明是固定化毛栓菌的合适载体。此外，干凝胶促进了漆酶活性的提高，最大活性值达到约20±1 U/mL。这些活性远高于使用其他知名惰性载体所获得的活性。然而，未发现载体形态与生产率之间的关系。所获得的令人鼓舞的结果为开发新型基于石墨烯的微生物固定化载体铺平了道路。
