1 The contribution of public networks to knowledge accumulation: Ex situ collections in microbial research Per M. Stromberg a 1 , Tom Dedeurwaerdere b , Unai Pascual c a University of Cambridge, Department of Land Economy, 19 Silver Street, Cambridge, UK. strombergp@yahoo.com b Université catholique de Louvain, Centre for the Philosophy of Law (CPDR), Belgium. tom.dedeurwaerdere@uclouvain.be c University of Cambridge, Department of Land Economy, 19 Silver Street, Cambridge, UK. up211@cam.ac.uk status : manuscript 23 nov 2008 Abstract Microbial ex-situ collections provide tangible use value for private and public companies and research organizations. The paper addresses the factors that affect conservation of microbial type strains by collections and their distributional policy. A unique worldwide survey of microbial collections provides empirical support for the need of a public-private institutional design to ensure knowledge accumulation in microbial and genetic material used in life science research. Results suggest that the industry relies on public research infrastructure through microbial collections. Results also indicate that public research infrastructure is the basis for distribution of inputs for both basic and applied research. Keywords: Life science research, public research institutions, knowledge networks, microbial commons, ex-situ biodiversity conservation 1 Corresponding author. Present address: United Nations University Institute of Advanced Studies, 6F International Organizations Center, Pacifico-Yokohama, 1-1-1 Minato Mirai, Nishi-ku, Yokohama 220-8502, Japan. Tel: +81-45-221-2300. Fax: +81-45-221-2302.