Improvement of chaetominine production by tryptophan feeding and medium optimization in submerged fermentation of Aspergillus fumigatus CY018

Abstract

Background

Chaetominine (CHA) is a novel alkaloid with excellent medicinal activities produced by Aspergillus fumigatus CY018. However, its further application has been severely restricted by the low production yield. In this work, the fermentation titer of CHA was investigated by medium composition optimization and amino-acid addition strategies.

Results

Under the optimized conditions of sucrose 115.03 g/L, ammonium acetate 3.98 g/L, d-tryptophan 3.84 g/L, KH₂PO₄ 1.5 g/L, FeSO₄·7H₂O 0.02 g/L, MgSO₄·7H₂O 0.7 g/L, sodium glutamate 3 g/L, sodium tartrate 1.5 g/L, and CaCl₂ 0.045 g/L), a CHA production yield of 55.92 mg/L was obtained, which increased significantly (3.99-fold) as compared with the unoptimized basal medium. Scale-up fermentation was carried out in a 5-L bioreactor based on the shake-flask fermentation results, maximum CHA yield of 48.53 mg/L was obtained at an air flow rate of 2.0 ± 0.1 VVM and an agitation rate of 400 rpm.

Conclusion

These results demonstrated that medium composition optimization and amino-acid addition were useful strategies for improving CHA production via biotechnological process. The methods in this work would be useful for the biotechnological production of CHA from A. fumigatus.

Keywords

Chaetominine / Aspergillus fumigatus / Medium optimization / d-Tryptophan')">d-Tryptophan

References

[1] Cai MH, Zhou XS, Zhou JS, Niu CP, Kang L, Sun XQ, Zhang YX. Efficient strategy for enhancing aspergiolide A production by citrate feedings and its effects on sexual development and growth of marine-derived fungus Aspergillus glaucus. Bioresour Technol, 2010, 101: 6059-6068.

[2] Chen GQ, Fan KW, Lu FP, Li Q, Aki T, Chen F, Jiang Y. Optimization of nitrogen source for enhanced production of squalene from thraustochytrid Aurantiochytrium sp. New Biotechnol, 2010, 27: 382-389.

[3] Eriksen SH, Jensen B, Schneider I, Kaasgaard S, Olsen J. Utilization of side-chain precursor for penicillin biosynthesis in a high-producing strain of Penicillium chrysogenum. Appl Microbiol Biotechnol, 1994, 40: 883-887.

[4] Hur BK, Cho DW, Kim HJ, Park CI, Suh HJ. Effect of culture conditions on growth and production of docosahexaenoic acid (DHA) using Thraustochytrium aureum ATCC 34304. Biotechnol Bioprocess Eng, 2002, 7: 10-15.

[5] Jiao RH, Xu S, Liu JY, Ge HM, Hui D, Chen X, Zhu HL, Tan RX. Chaetominine, a cytotoxic alkaloid produced by endophytic Chaetomium sp. IFB-E015. Org Lett, 2007, 8: 5709-5712.

[6] Kusari S, Satpal S, Jayabaskaran C. Biotechnological potential of plant-associated endophytic fungi: hope versus hype. Trends Biotechnol, 2014, 32: 297-303.

[7] Liu CQ, Jiao RH, Yao LY, Zhang YP, Lu YH, Tan RX. Adsorption characteristics and preparative separation of chaetominine from Aspergillus fumigatus mycelia by macroporous resin. J Chromatogr B, 2016, 1015: 135-141.

[8] Malgesini B, Forte B, Borghi D, Quartieri F, Gennari C, Papeo G. A straightforward total synthesis of (-)-chaetominine. Chemistry, 2009, 15: 7922-7929.

[9] Marienhagen J, Bott M. Metabolic engineering of microorganisms for the synthesis of plant natural products. J Biotechnol, 2013, 163: 166-178.

[10] Peng QL, Luo SP, Xia XE, Liu LX, Huang PQ. The four-step total synthesis of (−)-chaetominine. Chem Commun, 2014, 50: 1986-1988.

[11] Shen L, Zhu L, Luo Q, Li XW, Xi JQ, Kong GM, Song YC. Fumigaclavine I, a new alkaloid isolated from endophyte Aspergillus terreus. Chin J Nat Med, 2015, 13: 937-941.

[12] Snider BB, Wu XX. Synthesis of (−)-chaetominine. Org Lett, 2007, 9: 4913-4915.

[13] Tey BT, Yong KH, Ong HP, Ling TC, Ong ST, Tan YP. Optimal conditions for hepatitis B core antigen production in shaked flask fermentation. Biotechnol Bioprocess Eng, 2014, 9: 374-378.

[14] Toumi M, Couty F, Marrot J, Evano G. Total synthesis of chaetominine. Org Lett, 2008, 10: 5027-5030.

[15] Wei ZH, Bai LQ, Deng ZX, Zhong JJ. Impact of nitrogen concentration on validamycin a production and related gene transcription in fermentation of Streptomyces hygroscopicus 5008. Bioprocess Biosyst Eng, 2012, 35: 1201-1208.

[16] Xu W, Gavia DJ, Tang Y. Biosynthesis of fungal indole alkaloids. Nat Prod Rep, 2014, 31: 1474-1487.

[17] Xu D, Liang KJ, Tong XG, Ding M, Li DS, Xia CF. Biomimetic synthesis of (−)-chaetominine epimers via copper-catalyzed radical cyclization. Tetrahedron, 2015, 71: 3699-3704.

[18] Yao JY, Jiao RH, Liu CQ, Zhang YP, Yu WG, Lu YH, Tan RX. Assessment of the cytotoxic and apoptotic effects of chaetominine in a human leukemia cell line. Biomol Ther, 2016, 24: 147-155.

[19] Yoon JS, Kim JY, Rhee YH. Effects of amino acid addition on molar fraction of 3-hydroxyvalerate in copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate synthesized by Alcaligenes sp. SH-69. J Ferment Bioeng, 1995, 80: 350-354.

[20] Zhou J, He H, Wang XL, Lu J, Zhou XS, Cai MH, Zhang YX. Optimization of nutrients for dinactin production by a marine Streptomyces sp. from the high latitude arctic. Biotechnol Bioprocess Eng, 2015, 20: 725-732.

[21] Zhu YX, Hu WW, Yao LY, Yu WG, Jiao RH, Lu YH, Tan RX. Improvement of Fumigaclavine C production in a two-stage culture of Aspergillus fumigatus with molasses as a cost-effective ingredient. Biotechnol Bioprocess Eng, 2015, 20: 1106-1113.

Funding

National High Technology Research and Development Program of China(2013AA092901)

National Special Fund for State Key Laboratory of Bioreactor Engineering(2060204)