MINI-REVIEW Oxalate decarboxylase: biotechnological update and prevalence of the enzyme in filamentous fungi Miia R. Mäkelä & Kristiina Hildén & Taina K. Lundell Received: 23 March 2010 / Revised: 26 April 2010 / Accepted: 26 April 2010 / Published online: 13 May 2010 # Springer-Verlag 2010 Abstract Oxalate decarboxylase (ODC) is a manganese- containing, multimeric enzyme of the cupin protein superfamily. ODC is one of the three enzymes identified to decompose oxalic acid and oxalate, and within ODC catalysis, oxalate is split into formate and CO 2 . This primarily intracellular enzyme is found in fungi and bacteria, and currently the best characterized enzyme is the Bacillus subtilis OxdC. Although the physiological role of ODC is yet unidentified, the feasibility of this enzyme in diverse biotechnological applications has been recognized for a long time. ODC could be exploited, e.g., in diagnostics, therapeutics, process industry, and agriculture. So far, the sources of ODC enzyme have been limited including only a few fungal and bacterial species. Thus, there is potential for identification and cloning of new ODC variants with diverse biochemical properties allowing e.g. more enzyme fitness to process applications. This review gives an insight to current knowledge on the biochemical characteristics of ODC, and the relevance of oxalate-converting enzymes in biotechnological applications. Particular emphasis is given to fungal enzymes and the inter-connection of ODC to fungal metabolism of oxalic acid. Keywords Oxalate decarboxylase . Wood-decaying fungi . Oxalic acid . Basidiomycetes . Cupin protein Introduction Oxalic acid is an organic compound that is toxic to almost all organisms and cells. It is the smallest and strongest natural dicarboxylic acid with two pK a values of 1.23 and 4.26. In the biosphere and for cell metabolism, oxalate anions are major chelators of metal cations, e.g., Fe 2+ , Mn 2+ , Ca 2+ , and Al 3+ , and they participate to several environmental and biological processes such as leaching of metal deposits, precipitation of Ca, and defense reactions (Dutton and Evans 1996). Fungal species belonging to Ascomycota, Basidiomycota, and Zygomycota secrete con- siderable quantities of oxalate, and oxalic acid is factually the most common of the organic acids secreted by filamentous fungi. Oxalate is also abundant in many plants (Franceschi and Nakata 2005; Libert and Franceschi 1987) and synthe- sized by certain bacteria, such as Pseudomonas fluorescens and phytopathogenic Burkholderia glumae (Hamel et al. 1999; Nakata and He 2010). Three enzymes, or more specifically, three bio-catalytic activities for decomposition of oxalate and oxalic acid have been classified: (1) oxalate decarboxylase (ODC, oxalate carboxy-lyase, EC 4.1.1.2), (2) oxalate oxidase (OXO, oxalate:oxygen oxidoreductase, EC 1.2.3.4), and (3) oxalyl- CoA decarboxylase (oxalyl-CoA carboxy-lyase, EC 4.1.1.8; Fig. 1; reviewed by Svedružić et al. 2005). ODC activity was first described over 50 years ago in the mycelial extracts of the white-rot, wood-decaying fungi Trametes hirsuta (Coriolus hirsutus) and Flammulina (Collybia) velutipes (Shimazono 1955; Shimazono and Hayaishi 1957). Since then, ODC activity has been identified in a few fungal and bacterial species (Table 1), and ODC activity has also been reported in animal tissue (in the liver of guinea pigs; Murthy et al. 1981). M. R. Mäkelä (*) : T. K. Lundell Department of Food and Environmental Sciences, Division of Microbiology, Viikki Biocenter 1, P.O.B. 56, 00014 Helsinki, Finland e-mail: miia.r.makela@helsinki.fi K. Hildén School of Biology, University of Nottingham, Nottingham, UK Appl Microbiol Biotechnol (2010) 87:801–814 DOI 10.1007/s00253-010-2650-z