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Significance of Agitation-Induced Shear Stress on Mycelium Morphology and Lavendamycin Production by Engineered Streptomyces Flocculus

Xue Xia, Shuangjun Lin, Xiao-Xia Xia, Feng-Song Cong, Jian-Jiang Zhong

Appl Microbiol Biotechnol. 2014 May;98(10):4399-407.

PMID: 24522728

Abstract:

Lavendamycin methyl ester (LME) is a derivative of a highly functionalized aminoquinone alkaloid lavendamycin and could be used as a scaffold for novel anticancer agent development. This work demonstrated LME production by cultivation of an engineered strain of Streptomyces flocculus CGMCC4.1223 ΔstnB1, while the wild-type strain did not produce. To enhance its production, the effect of shear stress and oxygen supply on ΔstnB1 strain cultivation was investigated in detail. In flask culture, when the shaking speed increased from 150 to 220 rpm, the mycelium was altered from a large pellet to a filamentous hypha, and the LME production was almost doubled, while no significant differences were observed among varied filling volumes, which implied a crucial role of shear stress in the morphology and LME production. To confirm this suggestion, experiments with agitation speed ranging from 400 to 1,000 rpm at a fixed aeration rate of 1.0 vvm were conducted in a stirred tank bioreactor. It was found that the morphology became more hairy with reduced pellet size, and the LME production was enhanced threefolds when the agitation speed increased from 400 to 800 rpm. Further experiments by varying initial k L a value at the same agitation speed indicated that oxygen supply only slightly affected the physiological status of ΔstnB1 strain. Altogether, shear stress was identified as a major factor affecting the cell morphology and LME production. The work would be helpful to the production of LME and other secondary metabolites by filamentous microorganism cultivation.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP3930196 Streptonigrin from Streptomyces flocculus Streptonigrin from Streptomyces flocculus 3930-19-6 Price
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