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Fig. 3 | Microbial Cell Factories

Fig. 3

From: In vivo characterization of the activities of novel cyclodipeptide oxidases: new tools for increasing chemical diversity of bioproduced 2,5-diketopiperazines in Escherichia coli

Fig. 3

Detection of CDPs and their derivatives in culture supernatants of E. coli bacteria overexpressing CDPS and CDO. Culture supernatants of E. coli bacteria overexpressing no enzyme (a) or a CDPS/CDO couple from one pathway (b, N. potens; c, pathway 1 of A. oligospora; d, S. catenulae; e, S. rimosus; f, S. sp. NRRL 5123; g, pathway 2 of A. oligospora; h, S. aidingensis) were collected, treated by SPE, and analysed by LC–MSMS. UV traces recorded at 214 nm are shown between 16 and 31 min. The Y axes of the UV214 traces were set from 20 to 280 mAU. Recovered CDPs and the m/z values of their MH+ ions are indicated in grey. Stars indicate CDPs that have not been previously described for the characterized CDPSs. The m/z values of detected MH+ parent ions corresponding to dehydrogenated CDPs (loss of 2 and 4 atomic mass units) are shown in brown. The experiment was performed three times with similar results. Compounds chosen for purification and NMR characterization are indicated in black bold Arabic numbers in brackets (15)

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