Project description:Investigation of whole genome gene expression level in motile strain of Sphingomonas. sp A1 All flagellar genes in motile strain of Sphingomonas. sp A1 are highly transcribed.
Project description:Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a persistent nitramine explosive with long-lasting properties. Rhodococcus sp. strain DN22 has been discovered as one of the microorganisms capable of RDX degradation. Despite respectable studies on Rhodococcus sp. strain DN22, the proteins participating in RDX degradation (Oxidoreductase and Cytochrome P450) in the strain remain to be fragments. In this study, complete genome of Rhodococcus sp. strain DN22 was sequenced and analyzed, and the entire sequences of the two genes encoding Oxidoreductase and Cytochrome P450 in Rhodococcus sp. strain DN22 were predicted, which were validated through proteomic data. Besides, despite the identification of certain chemical substances as proposed characterized degradation intermediates of RDX, few studies have investigated the physiological changes and metabolic pathways occurring within Rhodococcus sp. cells when treated with RDX, particularly through the use of mass spectrometry-based omics. Hence, proteomics and metabolomics of Rhodococcus sp. strain DN22 were performed and analyzed with the presence or absence of RDX in the medium. A total of 3186 protein groups were identified and quantified between the two groups, with 117 proteins being significantly differentially expressed proteins. A total of 1056 metabolites were identified after merging positive and negative ion modes, among which 131 metabolites were significantly differential. Through the combined analysis of differential proteomics and metabolomics, several KEGG pathways, including two-component system, ABC transporters, alanine, aspartate and glutamate metabolism, arginine biosynthesis, purine metabolism, nitrogen metabolism, and phosphotransferase system (PTS) were found to be significantly enriched. We expect that our investigation will expand the acquaintance of Rhodococcus sp. strain DN22, and the knowledge of microbial degradation.
Project description:Many bacteria, often associated with eukaryotic hosts and of relevance for biotechnological applications, harbor a multipartite genome composed of more than one replicon. Biotechnologically relevant phenotypes are often encoded by genes residing on the secondary replicons. A synthetic biology approach to developing enhanced strains for biotechnological purposes could therefore involve merging pieces or entire replicons from multiple strains into a single genome. Here we report the creation of a genomic hybrid strain in a model multipartite genome species, the plant-symbiotic bacterium Sinorhizobium meliloti. We term this strain as cis-hybrid, since it is produced by genomic material coming from the same species' pangenome. In particular, we moved the secondary replicon pSymA (accounting for nearly 20% of total genome content) from a donor S. meliloti strain to an acceptor strain. The cis-hybrid strain was screened for a panel of complex phenotypes (carbon/nitrogen utilization phenotypes, intra- and extracellular metabolomes, symbiosis, and various microbiological tests). Additionally, metabolic network reconstruction and constraint-based modeling were employed for in silico prediction of metabolic flux reorganization. Phenotypes of the cis-hybrid strain were in good agreement with those of both parental strains. Interestingly, the symbiotic phenotype showed a marked cultivar-specific improvement with the cis-hybrid strains compared to both parental strains. These results provide a proof-of-principle for the feasibility of genome-wide replicon-based remodelling of bacterial strains for improved biotechnological applications in precision agriculture.