title: Bacteria-induced static batch fungal fermentation of the diterpenoid cyathin A(3), a small-molecule inducer of nerve growth factor.
abstract: Cyathin A(3), produced by the fungus Cyathus helenae, is a member of the cyathane family of diterpene natural products. While many of the cyathanes display antibacterial/antimicrobial activity or have cytotoxic activity against human cancer cell lines, their most exciting therapeutic potential is derived from their ability to induce nerve growth factor (NGF) release from glial cells, making the cyathanes attractive lead molecules for the development of neuroprotective therapeutics to prevent/treat Alzheimer's disease. To investigate if cyathin A(3) has NGF-inducing activity, we set out to obtain it using published C. helenae bench-scale fungal fermentations. However, to overcome nonproducing fermentations, we developed an alternative, bacteria-induced static batch fermentation approach to the production of cyathin A(3), as described in this report. HPLC, UV absorption spectra, and mass spectrometry identify cyathin A(3) in fungal fermentations induced by the timely addition of Escherichia coli K12 or Bacillus megabacterium. Pre-filtration of the bacterial culture abolishes cyathin A(3) induction, suggesting that bacteria-associated media changes or physical interaction between the fungus and bacteria underlie the induction mechanism. Through alteration of incubation conditions, including agitation, the timing of induction, and media composition, we optimized the fermentation to yield nearly 1 mg cyathin A(3)/ml media, a sixfold increase over previously described yields. Additionally, by comparison of fermentation profiles, we reveal that cyathin A(3) biosynthesis is regulated by carbon catabolite repression. We have used an enzyme-linked immunosorbent assay to illustrate that cyathin A(3) induces NGF release from cultured glial cells, and therefore cyathin A(3) warrants further examination in the development of neuroprotective therapeutics.
authors: Department of Chemistry and Biochemistry, George Mason University, Manassas, VA 20110, USA.
authors: Emma
authors: E
authors: Dixon
authors: Tatiana
authors: T
authors: Schweibenz
authors: Alison
authors: A
authors: Hight
authors: Brian
authors: B
authors: Kang
authors: Allyson
authors: A
authors: Dailey
authors: Sarah
authors: S
authors: Kim
authors: Meng-Yang
authors: MY
authors: Chen
authors: Yura
authors: Y
authors: Kim
authors: Sarah
authors: S
authors: Neale
authors: Ashley
authors: A
authors: Groth
authors: Trish
authors: T
authors: Ike
authors: Sarah
authors: S
authors: Khan
authors: Brandon
authors: B
authors: Schweibenz
authors: David
authors: D
authors: Lieu
authors: David
authors: D
authors: Stone
authors: Tania
authors: T
authors: Orellana
authors: Robin D
authors: RD
authors: Couch
mesh_terms: D001410:Bacillus megaterium / Q000502:physiology; D045744:Cell Line, Tumor; D055365:Cyathus / Q000378:metabolism*; D004224:Diterpenes / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D048168:Escherichia coli K12 / Q000502:physiology; D005285:Fermentation; D006801:Humans; D056265:Microbial Interactions; D020932:Nerve Growth Factor / Q000378:metabolism*
chemical_list: D004224:Diterpenes; D020932:Nerve Growth Factor; C560513:cyathin A3