Search results for "Actinorhodin"
showing 10 items of 13 documents
Plasma modified PLA electrospun membranes for actinorhodin production intensification in Streptomyces coelicolor immobilized-cell cultivations
2017
Most of industrially relevant bioproducts are produced by submerged cultivations of actinomycetes. The immobilization of these Gram-positive filamentous bacteria on suitable porous supports may prevent mycelial cell-cell aggregation and pellet formation which usually negatively affect actinomycete submerged cultivations, thus, resulting in an improved biosynthetic capability. In this work, electrospun polylactic acid (PLA) membranes, subjected or not to O2-plasma treatment (PLA-plasma), were used as support for immobilized-cell submerged cultivations of Streptomyces coelicolor M145. This strain produces different bioactive compounds, including the blue-pigmented actinorhodin (ACT) and red-p…
The SCO1731 methyltransferase modulates actinorhodin production and morphological differentiation of Streptomyces coelicolor A3(2)
2018
AbstractStreptomyces coelicolor is a Gram-positive microorganism often used as a model of physiological and morphological differentiation in streptomycetes, prolific producers of secondary metabolites with important biological activities. In the present study, we analysed Streptomyces coelicolor growth and differentiation in the presence of the hypo-methylating agent 5′-aza-2′-deoxycytidine (5-aza-dC) in order to investigate whether cytosine methylation has a role in differentiation. We found that cytosine demethylation caused a delay in spore germination, aerial mycelium development, sporulation, as well as a massive impairment of actinorhodin production. Thus, we searched for putative DNA…
Enhancement of antibiotic productions by plasma modified PLA electrospun membranes in Streptomyces coelicolor immobilized-cell cultivations
2017
This study, encouraging the use of PLA membranes for actinomycetes cultivations, could unveil functional insights associated with antibiotic production and S. coelicolor cellimmobilization
Effect of PCL/PEG-Based Membranes on Actinorhodin Production in Streptomyces coelicolor Cultivations
2015
The actinomycetes, Gram-positive filamentous bacteria, are the most prolific source of natural occurring antibiotics. At an industrial level, antibiotics from actinomycete strains are produced by means of submerged fermentations, where one of the major factors negatively affecting bioproductivity is the pellet-shaped biomass growth. The immobilization of microorganisms on properly chosen supports prevents cell-cell aggregation resulting in improving the biosynthetic capability. Thus, novel porous biopolymer-based devices are developed by combining melt mixing and particulate leaching. In particular, polycaprolactone (PCL), polyethylene glycol (PEG), and sodium chloride (NaCl) with different…
The Streptomyces coelicolor Small ORF trpM Stimulates Growth and Morphological Development and Exerts Opposite Effects on Actinorhodin and Calcium-De…
2020
In actinomycetes, antibiotic production is often associated with a morpho-physiological differentiation program that is regulated by complex molecular and metabolic networks. Many aspects of these regulatory circuits have been already elucidated and many others still deserve further investigations. In this regard, the possible role of many small open reading frames (smORFs) in actinomycete morpho-physiological differentiation is still elusive. In Streptomyces coelicolor, inactivation of the smORF trpM (SCO2038) – whose product modulates L-tryptophan biosynthesis – impairs production of antibiotics and morphological differentiation. Indeed, it was demonstrated that TrpM is able to interact w…
Effect of Streptomyces coelicolor M145 cell immobilization on actinorhodin production
2016
Non previsto
TrpM, a Small Protein Modulating Tryptophan Biosynthesis and Morpho-Physiological Differentiation in Streptomyces coelicolor A3(2).
2016
In the model actinomycete Streptomyces coelicolor A3(2), small open reading frames encoding proteins with unknown functions were identified in several amino acid biosynthetic gene operons, such as SCO2038 (trpX) in the tryptophan trpCXBA locus. In this study, the role of the corresponding protein in tryptophan biosynthesis was investigated by combining phenotypic and molecular analyses. The 2038KO mutant strain was characterized by delayed growth, smaller aerial hyphae and reduced production of spores and actinorhodin antibiotic, with respect to the WT strain. The capability of this mutant to grow on minimal medium was rescued by tryptophan and tryptophan precursor (serine and/or indole) su…
PCL/PEG based membranes for bacterial cells immobilization stimulate actinorhodin antibiotic production in S. coelicolor
2015
The actinomycetes, Gram-positive filamentous bacteria, are the most prolific source of natural antibiotics. At industrial level, antibiotics from actinomycetes are usually produced at low levels by mean of fermentative processes in submerged cultivations, where one of the major factors negatively affecting bioproductivity is the phenomenon of a pellet-shaped biomass growth. The strategies based on cell-immobilization, which were already proven improving bacterial bioprocess productivity, could stimulate antibiotic production in actinomycetes.
Actinorhodin production intensification by nanofibrous membranes in Streptomyces coelicolor cultures
2016
In this work, electrospun polycaprolactone (PCL) and polylactic acid (PLA) membranes, subjected or not to O2-plasma treatment, werwe used as support for cell-immobilization in S. coelicolor immobilized-cells created a compact biofilm on both kinds of membranes.
Tryptophan promotes morphological and physiological differentiation in Streptomyces coelicolor.
2015
The molecular mechanisms regulating tryptophan biosynthesis in actinomycetes are poorly understood; similarly, the possible roles of tryptophan in the differentiation program of microorganism life-cycle are still underexplored. To unveil the possible regulatory effect of this amino acid on gene expression, an integrated study based on quantitative teverse transcription-PCR (qRT-PCR) and proteomic approaches was performed on the actinomycete model Streptomyces coelicolor. Comparative analyses on the microorganism growth in a minimal medium with or without tryptophan supplementation showed that biosynthetic trp gene expression in S. coelicolor is not subjected to a negative regulation by the …