International Journal of Bio-Inorganic Hybrid Nanomaterials ABSTRACT In this work, the effect of immobilization of bread yeast (Saccharomyces cerevisiae) by sol-gel technique combined with functionalized nanoporous silica was investigated in different weight ratios of silica containing materials (TMOS: LUS-1). The activities of immobilized yeast in days after immobilization were examined. The results showed immobilization maintain the yeast life for a longer time. The functionalization by C18 functional group improved the environmental conditions for yeast life. These results indicate that the immobilization technique in the gel matrix and porous solid is a good system to develop industrial fermentations. Keyword: Nanoporous silica, Sol-gel, Bread yeast, LUS-1, Fermentation, Immobilization, Mesopore. (*) Corresponding Author - e-mail: abadiei@khayam.ut.ac.ir. Cells and Enzymes are immobilized by different meth- ods including absorption, covalent linkage, entrapment, cross linking and microencapsulation [1]. Produc- ing ethanol through consuming glucose is one of the - ing yeasts through removing the ethanol, it is needed to stabilize the yeasts leading to decrease the costs of separation steps [2]. Immobilization of cells in a silica metabolic activity, protection of environmental stresses - tion as a cellular storage systems in postponement of reactions [3]. Saccharomyces Cerevisiae (SC), a type of yeast bread, was utilized in this research. In order to immobilizing the yeast, entrapping technique by sol-gel method was used. Sol-gel method provides the Improvement in Immobilization of Bread Yeasts by Sol-gel Meth- od Combined with Functionalized Nanoporous Silica (LUS-1) Alireza Badiei 1* , Golriz Dadashi 2 , Hossein Attar 3 , Nastaran Hayati-Roodbari 4 1 Associate Professor, School of Chemistry, College of Science, University of Tehran, Tehran, Iran 2 M.Sc. Student, Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran 3 Associate Professor, Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran 4 Ph.D. Student, School of Chemistry, College of Science, University of Tehran, Tehran, Iran Received: 27 August 2013; Accepted: 6 November 2013 1. INTRODUCTION Int. J. Bio-Inorg. Hybd. Nanomat., Vol. 2, No. 4 (2013), 471-476 ISSN: 2251-8533