     β            !   " #$%  1 Institute of Food Engineering, Faculty of Engineering, University of Szeged, H6725 Szeged, Mars tér 7, Hungary 2 Department of Microbiology, Faculty of Science and Informatics, University of Szeged, H6726 Szeged, Közép fasor 52, Hungary βGlucosidases (βDglucoside glucohydrolases) play important role in nature, including the degradation of cellulosic biomass by fungi and bacteria, breakdown of glycolipids in mammalian lysosomes, and the cleavage of glycosylated flavonoids in plants. These enzymes have broad substrate specificity, and are used in a range of biotechnological processes. The most intensively studied area of their application is the saccharification of cellulosic biomass for fuel ethanol production. Their synthetic activity in the production of oligosaccharides and arylglycosides is also subject of intensive research. βGlucosidases from Zygomycetes can be produced in large amounts on cheap substrates using solid state fermentation which makes them promising candidates for biotechnological applications in the future. & Zygomycetes; βglucosidases, transglycosylase activity, liberation of aglycons, fuel ethanol production ’ ( βGlucosidases (βDglucoside glucohydrolases; EC3.2.1.21) catalyze the hydrolysis of alkyl and aryl βglycosides as well as disaccharides and short chain oligosaccharides. Many of them show also synthetic activity via reverse hydrolysis or transglycosylation [1]. βGlucosidases have a great potential to be used in various biotechnological processes from liberating flavours, aromas and isoflavone aglycons to the synthesis of oligosaccharides and alkyl glycosides. βGlucosidases are ubiquitous and can be found in bacteria, fungi, plants and animals. Fungal βglucosidases are parts of the cellulose degrading enzyme system working synergistically with endoglucanases and cellobiohydrolases. They split cellobiose into two molecules of glucose, protecting the above mentioned enzymes from the product inhibition effect of cellobiose. Their application in the conversion of highcellulosecontent biomass to fermentable sugars for the production of fuel ethanol is an intensively studied area [2]. Good βglucosidaseproducer fungi, usable in various biotechnological processes, synthesize enzymes with high hydrolyzing activity, heat and glucose tolerance, acid resistance, and possible transglycosylase activity [3]. Several fungi belonging to the Zygomycetes group are wellknown producers of extracellular enzymes, mainly proteases and lipases [4, 5]. These enzymes are used, e.g., in manufacturing of washing powders or in the food industry for cheese making. Some βglucosidases from different Zygomycetes have been purified and characterised [69]. In our study, βglucosidase was isolated from 94 strains representing 24 species of Zygomycetes, and 10 of them showed characteristics corresponding to the requirements described above [10]. The good enzyme production of these fungi under solid state fermentation conditions could be the bases of the cheap enzyme production. The acid and thermotolerant characteristics of some of these enzymes make them promising candidates in various special applications. ’ )    *  β βglucosidases are ubiquitous in the nature and can be found in bacteria, fungi, plants and animals. Their activity is fundamental in many biological pathways, such as degradation of structural and storage polysaccharides, hostpathogen interactions, cellular signalling, and oncogenesis [1]. In plants, they release pathogendefending compounds from their glycosidic bonds and activate phytohormons. βglucosidase deficiency in humans causes Gaucher’s disease. Fungal βglucosidases in winemaking yeasts contribute to the liberation of aromatic compounds. In moulds and whiterot fungi, they are parts of the cellulose degrading enzyme system together with various endo and exoglucanases. It seems that bacterial and yeast βglucosidases are mainly intracellular. Moulds secrete their enzymes extracellularly [1]. However, there are some exceptions: a novel, intracellular βglucosidase (BGLII) was purified from   [11]. It is suggested that cultivation conditions can influence the secretion of these enzymes in moulds: they are cellwallbound in submerged cultures but soluble under solid state fermentations [12]. We hypothesise that β glucosidases in moulds are, as part of the cellulase complex, inducible and might be released from the loose bonds of the cell wall and secreted into the environment in the presence of natural cellulose substrates. This theory is supported by the findings that extracellular and for the most part cellwallbound activities are related to the same enzyme [6, 11]. _______________________________________________________________________________________ Current Research, Technology and Education Topics in Applied Microbiology and Microbial Biotechnology A. Méndez-Vilas (Ed.) ©FORMATEX 2010 891