Diversa Corporation (Nasdaq: DVSA - News) today announced the issuance of U.S. Patent No. 6,566,050, directed to the discovery of enzymes from mixed populations of organisms, and U.S. Patent No. 6,562,594, directed to Diversa's Gene Site Saturation Mutagenesis(TM) (GSSM(TM)) technology. These patents are the latest additions to Diversa's extensive patent estate and serve to broaden Diversa's intellectual property position covering methods for the discovery and optimization of products using genomic technologies. The issuance of these patents brings Diversa's worldwide patent estate to 185 issued patents and more than 470 pending patents, including those assigned and/or licensed to Diversa. According to a recent survey by CHI Research and MIT Technology Review, the "Current-Impact Index" of Diversa's U.S. patents in 2002 was the highest of any other U.S. patent portfolio in the survey. Diversa's "Current- Impact Index" score of 14.43 demonstrated that Diversa's U.S. patents issued in the previous five years were cited as prior art in U.S. patents issued in 2002 1,343% more frequently than average.

The Diversa technologies covered by U.S. Patent No. 6,566,050 enable the rapid screening of microbial diversity for the discovery of novel enzymes. Traditional methods of discovery from mixed populations are both laborious and time consuming, because they require screening organisms, including cultured organisms, individually to discover product candidates. In contrast, high- throughput screening of mixed populations of organisms enables Diversa to rapidly discover product candidates from its gene libraries, which are currently estimated to contain the genes from more than three million unique microorganisms. Diversa's proprietary rapid screening capabilities are designed to discover novel biomolecules by screening both for biological activity and for specific DNA sequences of interest.

Diversa uses its patented, comprehensive GSSM technology to generate all possible single amino acid and codon substitutions in the expressed protein and related gene, respectively. Traditional mutagenesis methods typically target one amino acid site or a limited number of sites for optimization based upon, for example, structural information about the protein. In contrast, the GSSM technology enables all possible codon changes to be made and analyzed at each amino acid site, eliminating the need for prior knowledge about the protein structure. In addition, GSSM can be used to create double or triple site changes simultaneously. The proteins produced by the evolved genes are then screened for desired properties. This method can be particularly useful for the development of human therapeutic proteins, since it generates subtle changes to the protein structure that may yield significant improvements in activity while minimizing undesired properties, such as a negative immune response. For chemical and agricultural applications, improved product characteristics can include functionality at extreme temperatures and pH levels, as well as increased reaction rates.

Diversa Corporation is a leader in applying proprietary genomic technologies for the rapid discovery and optimization of novel products from genes and gene pathways. Diversa is directing its integrated portfolio of technologies to the discovery, evolution, and production of commercially valuable molecules with pharmaceutical applications, such as optimized monoclonal antibodies and orally active drugs, as well as enzymes and small molecules with agricultural, chemical, and industrial applications. In addition, Diversa has formed alliances and joint ventures with market leaders, such as Celera Genomics, The Dow Chemical Company, DuPont Bio-Based Materials, GlaxoSmithKline plc, Invitrogen Corporation, and affiliates of Syngenta AG.