Salt‐enhanced cultivation as a morphology engineering tool for filamentous actinomycetes: Increased production of labyrinthopeptin A1 in Actinomadura namibiensis. Issue 11 (8th September 2019)

• Record Type: Journal Article
• Authors: Tesche, Sebastian; Rösemeier‐Scheumann, René; Lohr, Jonas; Hanke, René; Büchs, Jochen; Krull, Rainer
• Is Part Of: Engineering in life sciences. Volume 19:Issue 11(2019)
• Page Start: 781
• Page End: 794
• Publication Date: 2019-09-08
• Subjects: actinomycete -- ammonium sulfate -- image analysis -- labyrinthopeptin -- morphology engineering -- salt‐enhanced cultivation; Bioengineering -- Periodicals; 660.605
• DOI: 10.1002/elsc.201900036
• Languages: English
• ISSNs: 1618-0240

Abstract

Abstract: Salt‐enhanced cultivation as a morphology engineering tool for the filamentous actinomycete Actinomadura namibiensis was evaluated in 500‐mL shaking flasks (working volume 100 mL) with the aim of increasing the concentration of the pharmaceutically interesting peptide labyrinthopeptin A1. Among the inorganic salts added to a complex production medium, the addition of (NH4 )2 SO4 led to the highest amount of labyrinthopeptin A1 production. By using 50 mM (NH4 )2 SO4, the labyrinthopeptin A1 concentration increased up to sevenfold compared to the non‐supplemented control, resulting in 325 mg L −1 labyrinthopeptin A1 after 10 days of cultivation. The performance of other ammonium‐ and sulfate‐containing salts (e.g., NH4 Cl, K2 SO4 ) was much lower than the performance of (NH4 )2 SO4 . A positive correlation between the uptake of glycerol as one of the main carbon sources and nongrowth‐associated labyrinthopeptin productivity was found. The change in the cell morphology of A. namibiensis in conjunction with increased osmolality by the addition of 50 mM (NH4 )2 SO4, was quantified by image analysis. A. namibiensis always developed a heterogeneous morphology with pellets and loose mycelia present simultaneously. In contrast to the non‐supplemented control, the morphology of (NH4 )2 SO4 ‐supplemented cultures was characterized by smaller and circular pellets that were more stable against disintegration in the stationary production phase.