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Characterization of a Newly Isolated Marine Fungus Aspergillus dimorphicus for Optimized Production of the Anti-Tumor Agent Wentilactones.

Xu R, Xu GM, Li XM, Li CS, Wang BG - Mar Drugs (2015)

Bottom Line: The result was further verified by fermentation scale-up for wentilactone production.Moreover, some small-molecule elicitors were found to have capacity of stimulating wentilactone production.The present study might be valuable for efficient production of wentilactones and fundamental investigation of the anti-tumor mechanism of norditerpenoids.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China. xrxurui@yeah.net.

ABSTRACT
The potential anti-tumor agent wentilactones were produced by a newly isolated marine fungus Aspergillus dimorphicus. This fungus was derived from deep-sea sediment and identified by polyphasic approach, combining phenotypic, molecular, and extrolite profiles. However, wentilactone production was detected only under static cultures with very low yields. In order to improve wentilactone production, culture conditions were optimized using the response surface methodology. Under the optimal static fermentation conditions, the experimental values were closely consistent with the prediction model. The yields of wentilactone A and B were increased about 11-fold to 13.4 and 6.5 mg/L, respectively. The result was further verified by fermentation scale-up for wentilactone production. Moreover, some small-molecule elicitors were found to have capacity of stimulating wentilactone production. To our knowledge, this is first report of optimized production of tetranorlabdane diterpenoids by a deep-sea derived marine fungus. The present study might be valuable for efficient production of wentilactones and fundamental investigation of the anti-tumor mechanism of norditerpenoids.

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Effects of environmental factors on the wentilactones production. WA (♦); WB (△). (A) Salinity; (B) initial pH; (C) temperature; and (D) culture time.
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marinedrugs-13-07040-f004: Effects of environmental factors on the wentilactones production. WA (♦); WB (△). (A) Salinity; (B) initial pH; (C) temperature; and (D) culture time.

Mentions: Previously, we found that these wentilactones could only be detected in static cultures (Figure 3). Almost no detectable wentilactones were produced in shaking cultures, which might be silent under these culture conditions. Therefore, different environmental factors were tested to get the optimal culture conditions. During our previous study, this fungus could grow and produce spores well in the modified PDB medium. It could also yield the largest biomass and total extracts. So the modified PDB medium was used for following static fermentation [14]. Then, a series of experiments were carried out with various salinity, initial pH, temperature, and culture time to determine their effects on wentilactone production [26]. As shown in Figure 4A–D, the salinity (17.5‰~35.0‰), initial pH (6~8), temperature (23~25 °C), and culture time (25~30 days), were better for wentilactone production. Salinity might be the main factor that affects the secondary metabolism of marine fungi, which is different from the terrestrial environment [27]. The pH value also affects the biosynthesis and accumulation of fungal products during fermentation [28]. The culture temperature might affect the biosynthesis of wentilactones by fungal growth [17]. Wentilactone production accumulated to high level at later stages, which is consistent with other fungal secondary metabolites.


Characterization of a Newly Isolated Marine Fungus Aspergillus dimorphicus for Optimized Production of the Anti-Tumor Agent Wentilactones.

Xu R, Xu GM, Li XM, Li CS, Wang BG - Mar Drugs (2015)

Effects of environmental factors on the wentilactones production. WA (♦); WB (△). (A) Salinity; (B) initial pH; (C) temperature; and (D) culture time.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663565&req=5

marinedrugs-13-07040-f004: Effects of environmental factors on the wentilactones production. WA (♦); WB (△). (A) Salinity; (B) initial pH; (C) temperature; and (D) culture time.
Mentions: Previously, we found that these wentilactones could only be detected in static cultures (Figure 3). Almost no detectable wentilactones were produced in shaking cultures, which might be silent under these culture conditions. Therefore, different environmental factors were tested to get the optimal culture conditions. During our previous study, this fungus could grow and produce spores well in the modified PDB medium. It could also yield the largest biomass and total extracts. So the modified PDB medium was used for following static fermentation [14]. Then, a series of experiments were carried out with various salinity, initial pH, temperature, and culture time to determine their effects on wentilactone production [26]. As shown in Figure 4A–D, the salinity (17.5‰~35.0‰), initial pH (6~8), temperature (23~25 °C), and culture time (25~30 days), were better for wentilactone production. Salinity might be the main factor that affects the secondary metabolism of marine fungi, which is different from the terrestrial environment [27]. The pH value also affects the biosynthesis and accumulation of fungal products during fermentation [28]. The culture temperature might affect the biosynthesis of wentilactones by fungal growth [17]. Wentilactone production accumulated to high level at later stages, which is consistent with other fungal secondary metabolites.

Bottom Line: The result was further verified by fermentation scale-up for wentilactone production.Moreover, some small-molecule elicitors were found to have capacity of stimulating wentilactone production.The present study might be valuable for efficient production of wentilactones and fundamental investigation of the anti-tumor mechanism of norditerpenoids.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao 266071, China. xrxurui@yeah.net.

ABSTRACT
The potential anti-tumor agent wentilactones were produced by a newly isolated marine fungus Aspergillus dimorphicus. This fungus was derived from deep-sea sediment and identified by polyphasic approach, combining phenotypic, molecular, and extrolite profiles. However, wentilactone production was detected only under static cultures with very low yields. In order to improve wentilactone production, culture conditions were optimized using the response surface methodology. Under the optimal static fermentation conditions, the experimental values were closely consistent with the prediction model. The yields of wentilactone A and B were increased about 11-fold to 13.4 and 6.5 mg/L, respectively. The result was further verified by fermentation scale-up for wentilactone production. Moreover, some small-molecule elicitors were found to have capacity of stimulating wentilactone production. To our knowledge, this is first report of optimized production of tetranorlabdane diterpenoids by a deep-sea derived marine fungus. The present study might be valuable for efficient production of wentilactones and fundamental investigation of the anti-tumor mechanism of norditerpenoids.

Show MeSH
Related in: MedlinePlus