Extremophiles and biotechnology: How far have we come? 1 2 Authors: Mark Paul Taylor, Lonnie Van Zyl, Marla Tuffin, Don Cowan 3 4 Institute for Microbial Biotechnology and Metagenomics, Department of 5 Biotechnology, University of the Western Cape, Modderdam Road, Bellville, Cape 6 Town. 7 8 Abstract 9 10 In principle, extremophiles have much to offer the biotechnology industry, from 11 robust enzymes capable of operating under the harshest of process conditions, to 12 metabolically diverse organisms producing value metabolites and applicable in 13 environments in which conventional engineered strains cannot function. However the 14 penetration of extremophilic organisms and their products into biotechnology markets 15 (technical and industrial enzymes, pharmaceuticals etc) has been modest at best. To 16 be successful, these products must compete this with highly engineering enzymes that 17 can be expressed in high yield and at low cost, and with organisms for which 18 established genetic tools are widely available and whose physiologies are understood 19 in greater detail (E. coli, Pichia spp.). 20 21 The exploitation and implementation of extremophiles, their enzymes and 22 biomolecules has been hindered in part by their „extreme‟ nature (where culturing 23 may require costly equipment and a “complicated” physiological environment which 24 is economically unattractive) and in part by the lack of genetic tools by which to 25 improve, adapt or engineer a process that would be based on an extremophilic host. 26 Technical issues aside, the increasing levels of legislative control over national 27 biological resources and a greater awareness of biopiracy have possibly slowed the 28 conversion of potential applications to reality, and have certainly made industrialists 29 increasingly wary of the credentials of the resources on which they may build a 30 technology or collaborate with academics. However, a number of historical examples 31 of successful commercialisation have been described, and form part of this review. It 32 is perhaps the creation of new biotechnology companies involved in the production of 33 biomolecules from renewable resources and the marketing of new industrial products, 34