Project description:This study is aimed to isolate marine actinomycetes from sediments from Andaman and the Gulf of Thailand. All 101 marine actinomycetes were screened for anti-biofilm activity. Streptomyces sp. GKU223 showed significantly inhibited biofilm formation of S. aureus. The evaluation of supernatants of anti-biofilm activity produced by Streptomyces sp. GKU223 has been performed. Since the interaction between marine actinomycetes and biofilm forming bacteria has never been investigated, proteomic analysis has been used to identify whole cell proteins involved in anti–biofilm activity. Understanding the interaction at molecular level will lead to sustainably use for anti-biofilm producing marine actinomycetes in pharmaceutical and medicinal applications in the future.
Project description:This study is aimed to isolate marine actinomycetes from sediments from Andaman and the Gulf of Thailand. All 101 marine actinomycetes were screened for anti-biofilm activity. Streptomyces sp. GKU 257-1 showed significantly inhibited biofilm formation of E. coli. The evaluation of supernatants of anti-biofilm activity produced by Streptomyces sp. GKU 257-1 has been performed. Since the interaction between marine actinomycetes and biofilm forming bacteria has never been investigated, proteomic analysis has been used to identify whole cell proteins involved in anti–biofilm activity. Understanding the interaction at molecular level will lead to sustainably use for anti-biofilm producing marine actinomycetes in pharmaceutical and medicinal applications in the future.
Project description:Actinomycete genomes contain a plethora of orphan gene clusters encoding unknown secondary metabolites, and representing a huge unexploited pool of chemical diversity. The explosive increase in genome sequencing and the massive advance of bioinformatic tools have revolutionized the rationale for natural product discovery from actinomycetes. In this context, we applied a genome mining approach to discover a group of unique catecholate-hydroxamate siderophores termed as qinichelins from Streptomyces sp. MBT76. Quantitative proteomics statistically correlated a gene cluster of interest (qch) to its unknown chemotype (qinichelin), after which structural elucidation of isolated qinichelin was assisted by bioinformatics analysis and verified by MS2 and NMR experiments. Strikingly, intertwined functional crosstalk among four separately located gene clusters was implicated in the biosynthesis of qinichelins.
Project description:Nucleoid-associated proteins (NAPs) are small, highly abundant regulators with low sequence specificity and pleiotropic mutant phenotypes. They are involved in transcriptional and post-transcriptional control of gene expression, DNA protection/repair and nucleoid structuring. Discovery of the major NAPs has been largely haphazard and based with the Enterobacteriaceae, although some Actinomycete-specific NAPs (Mdp1, Lsr2, sIHF) are known. Here, we use LC-MS/MS to systematically search for novel NAPs in isolated nucleoids of the model actinomycete Streptomyces coelicolor. Based on the criteria of high abundance (emPAI) and predicted DNA-binding ability (DNAbinder) we identified a set of around twenty proteins with a good probability of being NAPs. The approach was apparently successful as the set included known major NAPs HupA, sIHF and Lsr2 as well as the global regulators BldD and CRP. It also included a number of proteins whose functions are not yet known (SCO0204, SCO3013, SCO4232, SCO4199 and SCO1839) which provide a useful set of candidates for further study.
Project description:The aim of this work was to unveil the molecular mechanisms by which Streptomyces respond to a ROS intracellular imbalance and the effect of such response on the biosynthesis of secondary metabolites. The study was focused on the industrial actinomycete S. natalensis ATCC 27448 producer of the polyene pimaricin - an antifungal agent widely used in the food industry and promising for antiviral activity and stimulation of immune response.