An automated oxystat fermentation regime for microoxic cultivation of Magnetospirillum gryphiswaldense

Riese, Cornelius N.; Uebe, René; Rosenfeldt, Sabine; Schenk, Anna S.; Jérôme, Valérie; Freitag, Ruth; Schüler, Dirk

doi:10.1186/s12934-020-01469-z

Cited by 16 publications

(23 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Under microoxic and anoxic conditions, which are known to favor magnetosome biosynthesis (33,34), there were no significant differences detectable between the mutant and the wild type. However, in the extract of the wild-type strain grown under aerobic conditions that are known to inhibit magnetosome formation (33,34), we identified a compound with a mass of 691.38 Da which was absent from the Dtrans-at-pks mutant strain.…”

Section: Resultsmentioning

confidence: 90%

Sesbanimide R, a Novel Cytotoxic Polyketide Produced by Magnetotactic Bacteria

Awal

Haack

Bader

et al. 2021

mBio

Self Cite

View full text Add to dashboard Cite

Genomic information from various magnetotactic bacteria suggested that besides their common ability to form magnetosomes, they potentially also represent a source of bioactive natural products. By using targeted deletion and transcriptional activation, we connected a large biosynthetic gene cluster (BGC) of the trans-acyltransferase polyketide synthase (trans-AT PKS) type to the biosynthesis of a novel polyketide in the alphaproteobacterium Magnetospirillum gryphiswaldense. Structure elucidation by mass spectrometry and nuclear magnetic resonance spectroscopy (NMR) revealed that this secondary metabolite resembles sesbanimides, which were very recently reported from other taxa. However, sesbanimide R exhibits an additional arginine moiety the presence of which reconciles inconsistencies in the previously proposed sesbanimide biosynthesis pathway observed when comparing the chemical structure and the potential biochemistry encoded in the BGC. In contrast to the case with sesbanimides D, E, and F, we were able to assign the stereocenter of the arginine moiety experimentally and two of the remaining three stereocenters by predictive biosynthetic tools. Sesbanimide R displayed strong cytotoxic activity against several carcinoma cell lines. IMPORTANCE The findings of this study contribute a new secondary metabolite member to the glutarimide-containing polyketides. The determined structure of sesbanimide R correlates with its cytotoxic bioactivity, characteristic for members of this family. Sesbanimide R represents the first natural product isolated from magnetotactic bacteria and identifies this highly diverse group as a so-far-untapped source for the future discovery of novel secondary metabolites.

show abstract

Section: Resultsmentioning

confidence: 90%

Sesbanimide R, a Novel Cytotoxic Polyketide Produced by Magnetotactic Bacteria

Awal

Haack

Bader

et al. 2021

mBio

Self Cite

View full text Add to dashboard Cite

show abstract

“…6 b). To analyze growth at higher cell densities, strains ∆TZ-16::MAG- gusA and ∆TZ-17::MAG- gusA were in addition cultivated in a larger volume (3 l) in a bioreactor under controlled anaerobic conditions, which are known to be optimal for magnetosome biomineralization [ 28 , 62 ]. Figure 6 c shows exemplary results for strain ∆TZ-16::MAG- gusA compared to the WT.…”

Section: Resultsmentioning

confidence: 99%

Towards a 'chassis' for bacterial magnetosome biosynthesis: genome streamlining of Magnetospirillum gryphiswaldense by multiple deletions

et al. 2021

Self Cite

View full text Add to dashboard Cite

Background Because of its tractability and straightforward cultivation, the magnetic bacterium Magnetospirillum gryphiswaldense has emerged as a model for the analysis of magnetosome biosynthesis and bioproduction. However, its future use as platform for synthetic biology and biotechnology will require methods for large-scale genome editing and streamlining. Results We established an approach for combinatory genome reduction and generated a library of strains in which up to 16 regions including large gene clusters, mobile genetic elements and phage-related genes were sequentially removed, equivalent to ~ 227.6 kb and nearly 5.5% of the genome. Finally, the fragmented genomic magnetosome island was replaced by a compact cassette comprising all key magnetosome biosynthetic gene clusters. The prospective 'chassis' revealed wild type-like cell growth and magnetosome biosynthesis under optimal conditions, as well as slightly improved resilience and increased genetic stability. Conclusion We provide first proof-of-principle for the feasibility of multiple genome reduction and large-scale engineering of magnetotactic bacteria. The library of deletions will be valuable for turning M. gryphiswaldense into a microbial cell factory for synthetic biology and production of magnetic nanoparticles.

show abstract

“…Under microoxic and anoxic conditions, which are known to favour magnetosome biosynthesis (33,34), there were no significant differences detectable between the mutant and the wildtype. However, in the extract of the wild type strain grown under aerobic conditions that are known to inhibit magnetosome formation (33,34), we identified a compound with a mass of 691.38 Da which was absent from the mutant strain ∆trans-at-pks.…”

Section: Identification Deletion and Transcriptional Activation Of Amentioning

confidence: 90%

“…Up-scale cultivation of the PmamDC45-trans-at-pks strain was done in a 10 L BioFlow® Fermenter (Eppendorf) (34) under aerobic conditions with an initial OD565 of 0.04. A 900 ml culture grown under aerobic conditions was used as an inoculum for 9 L culture which was supplemented with 200 ml (v/v) XAD-16.…”

Section: Fermenter Cultivationmentioning

confidence: 99%

Sesbanimide R, a novel cytotoxic polyketide produced by magnetotactic bacteria

Awal

Haack

Bader

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Genomic information from various magnetotactic bacteria suggested that besides their common ability to form magnetosomes they potentially also represent a source of bioactive natural products. By using targeted deletion and transcriptional activation, we connected a large biosynthetic gene cluster (BGC) of the trans-AT PKS type to the biosynthesis of a novel polyketide in the alphaproteobacterium Magnetospirillum gryphiswaldense. Structure elucidation by mass spectrometry and NMR revealed that this secondary metabolite resembles sesbanimides which were very recently reported from other taxa. However, sesbanimide R exhibits an additional arginine moiety the presence of which reconciles inconsistencies in the previously proposed sesbanimide biosynthesis pathway when comparing the chemical structure and the potential biochemistry encoded in the BGC. In contrast to sesbanimides D, E and F, we were able to assign the stereocenter of the arginine moiety experimentally and two of the remaining three stereocenters by predictive biosynthetic tools. Sesbanimide R displayed strong cytotoxic activity against several carcinoma cell lines. ImportanceThe finding of this study contributes a new secondary metabolite member to the glutarimide-containing polyketides. The determined structure of sesbanimide R correlates with its cytotoxic bioactivity characteristic for members of this family. Sesbanimide R represents the first natural product isolated from magnetotactic bacteria and identifies this highly diverse group as a so far untapped source for the future discovery of novel secondary metabolites.

show abstract

An automated oxystat fermentation regime for microoxic cultivation of Magnetospirillum gryphiswaldense

Cited by 16 publications

References 52 publications

Sesbanimide R, a Novel Cytotoxic Polyketide Produced by Magnetotactic Bacteria

Sesbanimide R, a Novel Cytotoxic Polyketide Produced by Magnetotactic Bacteria

Towards a 'chassis' for bacterial magnetosome biosynthesis: genome streamlining of Magnetospirillum gryphiswaldense by multiple deletions

Sesbanimide R, a novel cytotoxic polyketide produced by magnetotactic bacteria

Contact Info

Product

Resources

About