Actinorhodin

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Murat Elibol - One of the best experts on this subject based on the ideXlab platform.

  • optimization of medium composition for Actinorhodin production by streptomyces coelicolor a3 2 with response surface methodology
    Process Biochemistry, 2004
    Co-Authors: Murat Elibol
    Abstract:

    Optimization of the fermentation medium for maximization of Actinorhodin production by Streptomyces coelicolor A3(2) was carried out. Response surface methodology (RSM) was applied to optimize the medium constituents. A 24 full-factorial central composite design (CCD) was chosen to explain the combined effects of the four medium constituents, viz. sucrose, glucose, yeast extract (YE) and peptone, and to design a minimum number of experiments. The P-values of the coefficients for linear, quadratic and cross-product effect of sucrose and glucose concentration were <0.0001, suggesting that these were critical variables having the greatest effect on the production of Actinorhodin in the complex medium. The optimized medium consisting of 339 g/l sucrose, 1 g/l glucose, 1.95 g/l YE and 2.72 g/l peptone predicted 195 mg/l of Actinorhodin which was 32% higher than that of the unoptimized medium. The amounts of glucose, YE and peptone required were also reduced with RSM.

  • response surface methodological approach for inclusion of perfluorocarbon in Actinorhodin fermentation medium
    Process Biochemistry, 2002
    Co-Authors: Murat Elibol
    Abstract:

    The combined effects of perfluorocarbon and glucose concentrations on Actinorhodin production by Streptomyces coelicolor A3(2) were studied in a 2-l bioreactor using response surface methodology. A 22 full-factorial central composite design was employed for experimental design and analysis of the results. The optimum PFC and glucose concentrations were found to be 42.7% and 12.25 g/l, respectively. In these conditions, Actinorhodin concentration of 60 mg/l with a biomass concentration of 1.9 g/l, a maximum volumetric oxygen uptake rate of 180 mgO2/l h and a glucose consumption rate of 0.110 g glucose/l h was attained. These results are in close agreement with the model predictions.

  • A kinetic model for Actinorhodin production by Streptomyces coelicolor A3(2)
    Process Biochemistry, 1999
    Co-Authors: Murat Elibol, Ferda Mavituna
    Abstract:

    Abstract The fermentation kinetics of an extracellular antibiotic, Actinorhodin, by Streptomyces coelicolor were studied in a batch system. A simple model was proposed using the Logistic equation for growth, the Luedeking–Piret equation for Actinorhodin production and Luedeking–Piret-like equations for glucose and oxygen consumptions. The model appeared to provide a reasonable description for each parameter during the growth phase.

  • Effect of sucrose on Actinorhodin production by Streptomyces coelicolor A3(2)
    Process Biochemistry, 1998
    Co-Authors: Murat Elibol, Ferda Mavituna
    Abstract:

    Abstract The effect of sucrose on Actinorhodin production by Streptomyces coelicolor was investigated using both defined and complex media. Both media contained glucose as the main carbon source and sucrose was included for osmotic balance. The production of antibiotic in the defined medium decreased with the addition of sucrose but, when sucrose was excluded from the complex medium, the culture did not produce Actinorhodin. A sucrose concentration of 340 g/litre was optimal for Actinorhodin production in the complex medium.

  • Production of Actinorhodin by Streptomyces coelicolor in batch and fed-batch cultures
    Process Biochemistry, 1997
    Co-Authors: Selma Ates, Murat Elibol, Ferda Mavituna
    Abstract:

    Abstract Fed-batch fermentations of Streptomyces coelicolor in chemically defined medium in a 20 litre bioreactor were used to produce Actinorhodin. Concentrated solutions of phosphate and nitrate with or without glucose were fed intermittently or continuously. Continuous feeding of glucose alone was found to be the best strategy for Actinorhodin production. In this case, the specific productivity was almost twice that obtained in conventional batch fermentation.

Mervyn J. Bibb - One of the best experts on this subject based on the ideXlab platform.

  • Synthetic RNA silencing of Actinorhodin biosynthesis
    2016
    Co-Authors: Gabriel C. Uguru, Mervyn J. Bibb, Shan Goh, Liam Good, James E. M. Stach
    Abstract:

    We demonstrate the first application of synthetic RNA gene silencers in Streptomyces coelicolor A3(2). Peptide nucleic acid and expressed antisense RNA silencers successfully inhibited Actinorhodin production. Synthetic RNA silencing was target-specific and is a new tool for gene regulation and metabolic engineering studies in Streptomyces

  • Synthetic RNA Silencing of Actinorhodin Biosynthesis in Streptomyces coelicolor A3(2)
    PLoS ONE, 2013
    Co-Authors: Gabriel C. Uguru, Mervyn J. Bibb, Andrew Hesketh, Madhav Mondhe, Shan Goh, Liam Good, James E. M. Stach
    Abstract:

    We demonstrate the first application of synthetic RNA gene silencers in Streptomyces coelicolor A3(2). Peptide nucleic acid and expressed antisense RNA silencers successfully inhibited Actinorhodin production. Synthetic RNA silencing was target-specific and is a new tool for gene regulation and metabolic engineering studies in Streptomyces.

  • the role of absc a novel regulatory gene for secondary metabolism in zinc dependent antibiotic production in streptomyces coelicolor a3 2
    Molecular Microbiology, 2009
    Co-Authors: Andrew Hesketh, Holger Kock, Saraspadee Mootien, Mervyn J. Bibb
    Abstract:

    The availability of zinc was shown to have a marked influence on the biosynthesis of Actinorhodin in Streptomyces coelicolor A3(2). Production of Actinorhodin and undecylprodigiosin was abolished when a novel pleiotropic regulatory gene, absC, was deleted, but only when zinc concentrations were low. AbsC was shown to control expression of the gene cluster encoding production of coelibactin, an uncharacterized non-ribosomally synthesized peptide with predicted siderophore-like activity, and the observed defect in antibiotic production was found to result from elevated expression of this gene cluster. Promoter regions in the coelibactin cluster contain predicted binding motifs for the zinc-responsive regulator Zur, and dual regulation of coelibactin expression by zur and absC was demonstrated using strains engineered to contain deletions in either or both of these genes. An AbsC binding site was identified in a divergent promoter region within the coelibactin biosynthetic gene cluster, adjacent to a putative Zur binding site. Repression of the coelibactin gene cluster by both AbsC and Zur appears to be required to maintain appropriate intracellular levels of zinc in S. coelicolor.

  • Stationary-phase production of the antibiotic Actinorhodin in Streptomyces coelicolor A3(2) is transcriptionally regulated
    Molecular Microbiology, 1993
    Co-Authors: Hugo Gramajo, Eriko Takano, Mervyn J. Bibb
    Abstract:

    Production of Actinorhodin, a polyketide antibiotic made by Streptomyces coelicolor A3(2), normally occurs only in stationary-phase cultures. S1 nuclease protection experiments showed that transcription of actII-ORF4, the activator gene required for expression of the biosynthetic structural genes, increased dramatically during the transition from exponential to stationary phase. The increase in actII-ORF4 expression was followed by transcription of the biosynthetic structural genes actIII and actVI-ORF1, and by the production of Actinorhodin. The presence of actII-ORF4 on a multicopy plasmid resulted in enhanced levels of actII-ORF4 mRNA, and transcription of actIII and Actinorhodin production during exponential growth, suggesting that Actinorhodin synthesis in rapidly growing cultures is normally limited only by the availability of enough of the activator protein. bldA, which encodes a tRNA(Leu)UUA that is required for the efficient translation of a single UUA codon in the actII-ORF4 mRNA, was transcribed throughout growth. Moreover, translational fusions of the 5' end of actII-ORF4 that included the UUA codon to the ermE reporter gene demonstrated the presence of functional bldA tRNA in young, exponentially growing cultures and no increase in the efficiency of translation of UUA codons, relative to UUG codons, was observed during growth. The normal growth-phase-dependent production of Actinorhodin in the liquid culture conditions used in these experiments appears to be mediated at the transcriptional level through activation of the actII-ORF4 promoter.

Wendy Champness - One of the best experts on this subject based on the ideXlab platform.

  • global negative regulation of streptomyces coelicolor antibiotic synthesis mediated by an absa encoded putative signal transduction system
    Journal of Bacteriology, 1996
    Co-Authors: Paul Brian, Perry Riggle, R A Santos, Wendy Champness
    Abstract:

    Streptomycete antibiotic synthesis is coupled to morphological differentiation such that antibiotics are produced as a colony sporulates. Streptomyces coelicolor produces several structurally and genetically distinct antibiotics. The S. coelicolor absA locus was defined by four UV-induced mutations that globally blocked antibiotic biosynthesis without blocking morphological differentiation. We show that the absA locus encodes a putative eubacterial two-component sensor kinase-response regulator system. All four mutations lie within a single open reading frame, designated absA1, which is predicted to encode a sensor histidine kinase. A second gene downstream of absA1, absA2, is predicted to encode the cognate response regulator. In marked contrast to the antibiotic-deficient phenotype of the previously described absA mutants, the phenotype caused by disruption mutations in the absA locus is precocious hyperproduction of the antibiotics Actinorhodin and undecylprodigiosin. Precocious hyperproduction of these antibiotics is correlated with premature expression of XylE activity in a transcriptional fusion to an Actinorhodin biosynthetic gene. We propose that the absA locus encodes a signal transduction mechanism that negatively regulates synthesis of the multiple antibiotics produced by S. coelicolor.

Joo-won Suh - One of the best experts on this subject based on the ideXlab platform.

  • S-Adenosyl-L-methionine Activates Actinorhodin Biosynthesis by Increasing Autophosphorylation of the Ser/Thr Protein Kinase AfsK in Streptomyces coelicolor A3(2)
    Bioscience Biotechnology and Biochemistry, 2011
    Co-Authors: Ying-yu Jin, Jinhua Cheng, Seung Hwan Yang, Lingzhu Meng, Sasikumar Arunachalam Palaniyandi, Xin-qing Zhao, Joo-won Suh
    Abstract:

    S-Adenosyl-L-methionine (SAM) is one of the major methyl donors in all living organisms. The exogenous treatment with SAM leads to increased Actinorhodin production in Streptomyces coelicolor A3(2). In this study, mutants from different stages of the AfsK-AfsR signal transduction cascade were used to test the possible target of SAM. SAM had no significant effect on Actinorhodin production in afsK, afsR, afsS, or actII-open reading frame 4 (ORF4) mutant. This confirms that afsK plays a critical role in delivering the signal generated by exogenous SAM. The afsK-pHJL-KN mutant did not respond to SAM, suggesting the involvement of the C-terminal of AfsK in binding with SAM. SAM increased the in vitro autophosphorylation of kinase AfsK in a dose-dependent manner, and also abolished the effect of decreased Actinorhodin production by a Ser/Thr kinase inhibitor, K252a. In sum, our results suggest that SAM activates Actinorhodin biosynthesis in S. coelicolor M130 by increasing the phosphorylation of protein kinase...

  • s adenosyl l methionine activates Actinorhodin biosynthesis by increasing autophosphorylation of the ser thr protein kinase afsk in streptomyces coelicolor a3 2
    Bioscience Biotechnology and Biochemistry, 2011
    Co-Authors: Ying-yu Jin, Jinhua Cheng, Seung Hwan Yang, Lingzhu Meng, Sasikumar Arunachalam Palaniyandi, Xin-qing Zhao, Joo-won Suh
    Abstract:

    S-Adenosyl-L-methionine (SAM) is one of the major methyl donors in all living organisms. The exogenous treatment with SAM leads to increased Actinorhodin production in Streptomyces coelicolor A3(2). In this study, mutants from different stages of the AfsK-AfsR signal transduction cascade were used to test the possible target of SAM. SAM had no significant effect on Actinorhodin production in afsK, afsR, afsS, or actII-open reading frame 4 (ORF4) mutant. This confirms that afsK plays a critical role in delivering the signal generated by exogenous SAM. The afsK-pHJL-KN mutant did not respond to SAM, suggesting the involvement of the C-terminal of AfsK in binding with SAM. SAM increased the in vitro autophosphorylation of kinase AfsK in a dose-dependent manner, and also abolished the effect of decreased Actinorhodin production by a Ser/Thr kinase inhibitor, K252a. In sum, our results suggest that SAM activates Actinorhodin biosynthesis in S. coelicolor M130 by increasing the phosphorylation of protein kinase...

  • Accumulation of S-Adenosyl-l-Methionine Enhances Production of Actinorhodin but Inhibits Sporulation in Streptomyces lividans TK23
    Journal of Bacteriology, 2003
    Co-Authors: Dongjin Kim, Soon-kwang Hong, Jung-hyun Huh, Young-yell Yang, Choong-min Kang, Inhyung Lee, Chang-gu Hyun, Joo-won Suh
    Abstract:

    S-Adenosyl-l-methionine synthetase (SAM-s) catalyzes the biosynthesis of SAM from ATP and l-methionine. Despite extensive research with many organisms, its role in Streptomyces sp. remains unclear. In the present study, the putative SAM-s gene was isolated from a spectinomycin producer, Streptomyces spectabilis. The purified protein from the transformed Escherichia coli with the isolated gene synthesized SAM from l-methionine and ATP in vitro, strongly indicating that the isolated gene indeed encoded the SAM-s protein. The overexpression of the SAM-s gene in Streptomyces lividans TK23 inhibited sporulation and aerial mycelium formation but enhanced the production of Actinorhodin in both agar plates and liquid media. Surprisingly, the overexpressed SAM was proven by Northern analysis to increase the production of Actinorhodin through the induction of actII-ORF4, a transcription activator of Actinorhodin biosynthetic gene clusters. In addition, we found that a certain level of intracellular SAM is critical for the induction of antibiotic biosynthetic genes, since the control strain harboring only the plasmid DNA did not show any induction of actII-ORF4 until it reached a certain level of SAM in the cell. From these results, we concluded that the SAM plays important roles as an intracellular factor in both cellular differentiation and antibiotic production in Streptomyces sp.

Rodney A. Fernandes - One of the best experts on this subject based on the ideXlab platform.