Project description:Streptomyces sp. M7 has demonstrated ability to remove lindane from culture media and soils. In this study, we used MS-based label-free quantitative proteomic to understand lindane degradation and its metabolic context in Streptomyces sp. M7. We identified the proteins involved in the up-stream degradation pathway. Our results demonstrated that mineralization of lindane is feasible since proteins from an unusual down-stream degradation pathway were also identified. Degradative steps were supported by an active catabolism that supplied energy and reducing equivalents in the form of NADPH. This is the first study in which degradation steps of an organochlorine compound and metabolic context are elucidate in a biotechnological genus as Streptomyces. These results serve as basement to study other degradative actinobacteria and to improve the degradation processes of Streptomyces sp. M7.
Project description:Ethyl Acetate fraction of Streptomyces sp. CBMAI 2042 was investigated for identifying cyclodepsipeptides using electrospray ionisation tandem mass spectrometry (ESI-MS/MS). Without prior isolation, the structural determination was achieved on the basis of mass fragmentation pattern and comparison with the previously established data. The ESI-MS of the fraction in the positive ion mode gave clusters of singly and doubly charged molecular ion peaks. The ESI-MS spectrum showed peaks for the presence of the cyclodepsipeptides Valinomycin, Montanastatin and at least 5 structural analogues never reported before.
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:Mining of fungal genomes uncovered their great potential for the production of novel secondary metabolites (SMs). However most of them stay silent under standard laboratory cultivation conditions. Co-cultivation of fungi with organism that occur in their natural habitat has shown to be trigger for the activation of such silent SM gene clusters. Recently, we showed that the cultivation of Aspergillus nidulans with the bacterium Streptomyces rapamycinicus leads to the activation of the orsellinic acid gene cluster. Hence we decided to study this interaction further to gain insight into the regulation of SM gene clusters and more specifically to study the chromatin remodelling network actuve upon co-cultivation of the two organisms. This study gives novel insight into the regulation of the orsellinic acid gene cluster and the interaction of the two organisms. To the best of our knowledge this is the first report of mapping the chromatin landscape of microbial interactions, making this study a role model for the analysis of similar systems.