title: Enhancement of Palmarumycins C(12) and C(13) production in liquid culture of endophytic fungus Berkleasmium sp. Dzf12 after treatments with metal ions.
abstract: The influences of eight metal ions (i.e., Na+, Ca2+, Ag+, Co2+, Cu2+, Al3+, Zn2+, and Mn4+) on mycelia growth and palmarumycins C(12) and C(13) production in liquid culture of the endophytic fungus Berkleasmium sp. Dzf12 were investigated. Three metal ions, Ca2+, Cu2+ and Al3+ were exhibited as the most effective to enhance mycelia growth and palmarumycin production. When calcium ion (Ca2+) was applied to the medium at  10.0 mmol/L on day 3, copper ion (Cu2+) to the medium at 1.0 mmol/L on day 3, aluminum ion (Al3+) to the medium at 2.0 mmol/L on day 6, the maximal yields of palmarumycins C(12) plus C(13) were obtained as 137.57 mg/L, 146.28 mg/L and 156.77 mg/L, which were 3.94-fold, 4.19-fold and 4.49-fold in comparison with that (34.91 mg/L) of the control, respectively. Al3+ favored palmarumycin C(12) production when its concentration was higher than 4 mmol/L. Ca2+ had an improving effect on mycelia growth of Berkleasmium sp. Dzf12. The combination effects of Ca2+, Cu2+ and Al3+ on palmarumycin C(13) production were further studied by employing a statistical method based on the central composite design (CCD) and response surface methodology (RSM). By solving the quadratic regression equation between palmarumycin C(13) and three metal ions, the optimal concentrations of Ca2+, Cu2+ and Al3+ in medium for palmarumycin C(13) production were determined as 7.58, 1.36 and 2.05 mmol/L, respectively. Under the optimum conditions, the predicted maximum palmarumycin C(13) yield reached 208.49 mg/L. By optimizing the combination of Ca2+, Cu2+ and Al3+ in medium, palmarumycin C(13) yield was increased to 203.85 mg/L, which was 6.00-fold in comparison with that (33.98 mg/L) in the original basal medium. The results indicate that appropriate metal ions (i.e., Ca2+, Cu2+ and Al3+) could enhance palmarumycin production. Application of the metal ions should be an effective strategy for palmarumycin production in liquid culture of the endophytic fungus Berkleasmium sp. Dzf12.
authors.affiliation: Department of Plant Pathology, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. lgzhou@cau.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Mou
authors.forename: Haiyu
authors.initials: H
authors.lastname: Luo
authors.forename: Ziling
authors.initials: Z
authors.lastname: Mao
authors.forename: Tijiang
authors.initials: T
authors.lastname: Shan
authors.forename: Weibo
authors.initials: W
authors.lastname: Sun
authors.forename: Kaiyi
authors.initials: K
authors.lastname: Zhou
authors.forename: Ligang
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000465:Algorithms; D000535:Aluminum / Q000494:pharmacology; D000704:Analysis of Variance; D001203:Ascomycota / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D018533:Biomass; D002118:Calcium / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D060026:Endophytes / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008670:Metals / Q000494:pharmacology*; D025282:Mycelium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D009172:Mycology / Q000379:methods; D009281:Naphthalenes / Q000378:metabolism*; D013141:Spiro Compounds / Q000378:metabolism*
chemical_list: D008670:Metals; D009281:Naphthalenes; D013141:Spiro Compounds; C462860:palmarumycin C12; C573593:palmarumycin C13; D003300:Copper; D000535:Aluminum; D002118:Calcium