Engineering of Streptoalloteichus tenebrarius 2444 for Sustainable Production of Tobramycin

Tobramycin is a broad-spectrum aminoglycoside antibiotic agent. The compound is obtained from the base-catalyzed hydrolysis of carbamoyltobramycin (CTB), which is naturally produced by the actinomycete Streptoalloteichus tenebrarius. However, the strain uses the same precursors to synthesize several structurally related aminoglycosides. Consequently, the production yields of tobramycin are low, and the compound’s purification is very challenging, costly, and time-consuming. In this study, the production of the main undesired product, apramycin, in the industrial isolate Streptoalloteichus tenebrarius 2444 was decreased by applying the fermentation media M10 and M11, which contained high concentrations of starch and dextrin. Furthermore, the strain was genetically engineered by the inactivation of the aprK gene (∆aprK), resulting in the abolishment of apramycin biosynthesis. In the next step of strain development, an additional copy of the tobramycin biosynthetic gene cluster (BGC) was introduced into the ∆aprK mutant. Fermentation by the engineered strain (∆aprK_1-17L) in M11 medium resulted in a 3- to 4-fold higher production than fermentation by the precursor strain (∆aprK). The phenotypic stability of the mutant without selection pressure was validated. The use of the engineered S. tenebrarius 2444 facilitates a step-saving, efficient, and, thus, more sustainable production of the valuable compound tobramycin on an industrial scale.

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Identification of the Biosynthetic Gene Cluster and an Additional Gene for Resistance to the Antituberculosis Drug Capreomycin

Applied and Environmental Microbiology ◽

10.1128/aem.00485-07 ◽

2007 ◽

Vol 73 (13) ◽

pp. 4162-4170 ◽

Cited By ~ 58

Author(s):

Elizabeth A. Felnagle ◽

Michelle R. Rondon ◽

Andrew D. Berti ◽

Heidi A. Crosby ◽

Michael G. Thomas

Keyword(s):

Gene Cluster ◽

Resistance Gene ◽

Aminoglycoside Antibiotic ◽

Biosynthetic Gene Cluster ◽

Multidrug Resistant ◽

23S Rrna ◽

Peptide Antibiotics ◽

Biosynthetic Gene ◽

Essential Components ◽

Initial Work

ABSTRACT Capreomycin (CMN) belongs to the tuberactinomycin family of nonribosomal peptide antibiotics that are essential components of the drug arsenal for the treatment of multidrug-resistant tuberculosis. Members of this antibiotic family target the ribosomes of sensitive bacteria and disrupt the function of both subunits of the ribosome. Resistance to these antibiotics in Mycobacterium species arises due to mutations in the genes coding for the 16S or 23S rRNA but can also arise due to mutations in a gene coding for an rRNA-modifying enzyme, TlyA. While Mycobacterium species develop resistance due to alterations in the drug target, it has been proposed that the CMN-producing bacterium, Saccharothrix mutabilis subsp. capreolus, uses CMN modification as a mechanism for resistance rather than ribosome modification. To better understand CMN biosynthesis and resistance in S. mutabilis subsp. capreolus, we focused on the identification of the CMN biosynthetic gene cluster in this bacterium. Here, we describe the cloning and sequence analysis of the CMN biosynthetic gene cluster from S. mutabilis subsp. capreolus ATCC 23892. We provide evidence for the heterologous production of CMN in the genetically tractable bacterium Streptomyces lividans 1326. Finally, we present data supporting the existence of an additional CMN resistance gene. Initial work suggests that this resistance gene codes for an rRNA-modifying enzyme that results in the formation of CMN-resistant ribosomes that are also resistant to the aminoglycoside antibiotic kanamycin. Thus, S. mutabilis subsp. capreolus may also use ribosome modification as a mechanism for CMN resistance.

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Heterologous production of kasugamycin, an aminoglycoside antibiotic from Streptomyces kasugaensis, in Streptomyces lividans and Rhodococcus erythropolis L-88 by constitutive expression of the biosynthetic gene cluster

Applied Microbiology and Biotechnology ◽

10.1007/s00253-017-8189-5 ◽

2017 ◽

Vol 101 (10) ◽

pp. 4259-4268 ◽

Cited By ~ 9

Author(s):

Kano Kasuga ◽

Akira Sasaki ◽

Takashi Matsuo ◽

Chika Yamamoto ◽

Yuiko Minato ◽

...

Keyword(s):

Gene Cluster ◽

Rhodococcus Erythropolis ◽

Constitutive Expression ◽

Aminoglycoside Antibiotic ◽

Biosynthetic Gene Cluster ◽

Streptomyces Lividans ◽

Heterologous Production ◽

Biosynthetic Gene

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Characterization of Methyltransferase from Apramycin Biosynthetic Gene Cluster and Improvement Production of Apramycin in Engineered Streptoalloteichus Tenebrarius

10.21203/rs.3.rs-927201/v1 ◽

2021 ◽

Author(s):

Junyang Sun ◽

Hongjing Gao ◽

Danyang Yan ◽

Yu Liu ◽

Xianpu Ni ◽

...

Keyword(s):

Escherichia Coli ◽

Gene Disruption ◽

Pasteurella Multocida ◽

Aminoglycoside Antibiotic ◽

Biosynthetic Gene Cluster ◽

Biosynthetic Gene ◽

Methyltransferase Gene ◽

Production Strain

Abstract BackgroundApramycin is a structurally unique aminoglycoside, used in veterinary medicine or the treatment of Salmonella, Escherichia coli and Pasteurella multocida infections in farm. Although discovered and used many years ago, many biosynthetic steps of apramycin are still obscure. ResultsIn this study, we identified a HemK family methyltransferase, aprI, involved in apramycin biosynthesis. The function of aprI was studied by using gene disruption and biochemical experiments, and a new aminoglycoside antibiotic demethyl-apramycin was purified from aprI disruption strain. Experiments proved that AprI converted demethyl-aprosamine to aprosamine in vitro. Based on this, the apramycin production strain was improved by overexpression the AprI to decrease the impurity production. ConclusionsWe have identified aprI is a 7’-N-methyltransferase gene in apramycin biosynthesis and confirmed the substrate of methyltransferase. Engineering of aprI resulted in a strain producing a new aminoglycoside demethyl-apramycin and apramycin mono-producing strain with less impurity production. Finally, the yield of demethyl-apramycin in apramycin mono-producing strain decreased from 196±36 mg/L to 51±9 mg/L, and the yield of apramycin increased from 2227±320 mg/L to 2331±210 mg/L.

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Anacyclamide D8P, a prenylated cyanobactin from a Sphaerospermopsis sp. cyanobacterium

10.26434/chemrxiv.5346739.v1 ◽

2017 ◽

Cited By ~ 1

Author(s):

Joana Martins ◽

Niina Leikoski ◽

Matti Wahlsten ◽

Joana Azevedo ◽

Jorge Antunes ◽

...

Keyword(s):

Gene Cluster ◽

Cyclic Peptides ◽

Biosynthetic Gene Cluster ◽

The Novel ◽

Tyrosine Residue ◽

Biosynthetic Gene ◽

Post Translational Modification ◽

Biological Assays ◽

Mass Spectrometric Data ◽

Spectrometric Data

Cyanobactins are a family of linear and cyclic peptides produced through the post-translational modification of short precursor peptides. Anacyclamides are macrocyclic cyanobactins with a highly diverse sequence that are common in the genus Anabaena. A mass spectrometry-based screening of potential cyanobactin producers led to the discovery of a new prenylated member of this family of compounds, anacyclamide D8P (1), from Sphaerospermopsis sp. LEGE 00249. The anacyclamide biosynthetic gene cluster (acy) encoding the novel macrocyclic prenylated cyanobactin, was sequenced. Heterologous expression of the acy gene cluster in Escherichia coli established the connection between genomic and mass spectrometric data. Unambiguous establishment of the type and site of prenylation required the full structural elucidation of 1 using Nuclear Magnetic Resonance (NMR), which demonstrated that a forward prenylation occurred on the tyrosine residue. Compound 1 was tested in pharmacologically or ecologically relevant biological assays and revealed moderate antimicrobial activity towards the fouling bacterium Halomonas aquamarina CECT 5000.

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