title: A new approach for improving cordycepin productivity in surface liquid culture of Cordyceps militaris using high-energy ion beam irradiation.
abstract: OBJECTIVE
  To obtain a higher cordycepin production using Cordyceps militaris mutant obtained by a new mutagenesis technique called 'ion beam'.
  
  
  RESULTS
  Successful irradiation of C. militaris NBRC 9787 by a proton beam with high energy was performed, and 30 classes of 8-azaadenine- and 28 classes of 8-azaaguanine-resistant mutants were obtained on mutant screening, of which seven classes were selected as promising preliminary mutants having an antibacterial ability as an index of cordycepin production. In a surface liquid culture technique, some of the 8-azaadenine-resistant mutants gave a better performance for the cordycepin productivity; in contrast, among the 8-azaaguanine-resistant mutants, it was shown that mutant no. G81-3 was much better than the control in the metabolic rate of glucose and the cordycepin productivity. In primary optimization using the enriched medium, the cordycepin production was 3.1 and 1.8 g l(-1) on 21-day culture for mutant no. G81-3 and the control, respectively. The cordycepin production obtained by the mutant was 72% more than the control.
  
  
  CONCLUSIONS
  The mutant obtained by proton beam irradiation had higher productivity of cordycepin than that of the control.
  
  
  CONCLUSIONS
  The mutant obtained by irradiation had a superior production performance of cordycepin, and therefore, it could be used in the realm of applied industrial biotechnology for the large-scale production of cordycepin.
authors.affiliation: Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, University of Fukui, Fukui, Japan.
authors.forename: S K
authors.initials: SK
authors.lastname: Das
authors.forename: M
authors.initials: M
authors.lastname: Masuda
authors.forename: M
authors.initials: M
authors.lastname: Hatashita
authors.forename: A
authors.initials: A
authors.lastname: Sakurai
authors.forename: M
authors.initials: M
authors.lastname: Sakakibara
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D032661:Cordyceps / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects*; D003470:Culture Media / Q000737:chemistry / Q000378:metabolism*; D003839:Deoxyadenosines / Q000378:metabolism*; D024881:Drug Resistance, Bacterial; D005821:Genetic Techniques; D016296:Mutagenesis; D009154:Mutation
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D003839:Deoxyadenosines; C058120:cordycepin