Identification of Cordyceps sinensis by 18S nrDNA Sequencing and Characterization of Fermented Products in Taiwan

Abstract

With increased demand for Cordyceps sinensis teleomorphs, anamorph fermented products have been used as substitutes. This has raised questionable quality control challenges and consequently the need for molecular methods to identify C. sinensis. Internal transcribed spacer-1 (ITS 1), 5.8S, and ITS 2 nrDNA sequence identities were only 85.7–100% between each C. sinensis isolate. However, 18S nrDNA NS5/NS6 region sequences were almost identical and have potential for molecular characterization and diversity of isolates. The NS5/NS6 region sequences were compared to GenBank data and other Cordyceps spp. The Cfo I and Rsa I restriction determined signature sequences were used to successfully characterize 12 fermented products. This innovative method can be applied to C. sinensis teleomorph and anamorph identification and to improve quality control.

Key Words:

• Cordyceps sinensis
• identification
• nrDNA
• signature sequence

ACKNOWLEDGMENTS

This study was supported by a grant (Grant No. DOH-91-TD-1163) from the Department of Health, Executive Yuan, Taiwan, Republic of China.