Project description:Here we have compared adult wildtype (N2) C. elegans gene expression when grown on different bacterial environments/fod sources in an effort to model naturally occuring nematode-bacteria interactions at the Konza Prairie. We hypothesize that human-induced changes to natural environments, such as the addition of nitrogen fertalizer, have effects on the bacterial community in soils and this drives downstream changes in the structure on soil bacterial-feeding nematode community structure. Here we have used transcriptional profiling to identify candidate genes involved in the interaction of nematodes and bacteria in nature.
Project description:Competition for limited iron resources is a key driver of microbial community structure in many regions of the surface ocean. The bacterial siderophores ferrioxamine and amphibactin have been identified in marine surface waters, suggesting that they may represent an important bacterial strategy for obtaining iron from a scarcely populated pool. We screened several strains of marine Vibrio for the presence of putative amphibactin biosynthesis gene homologues and amphibactin production. Whole cell proteomics, siderophore isolation, and isotopically labeled iron uptake experiments were performed. Here, we show that an amphibactin-producing marine bacterium, Vibrio cyclitrophicus str. 1F-53, harbors an independently regulated uptake pathway for ferrioxamines. Proteomic analyses identified upregulation of the amphibactin NRPS system and a putative amphibactin siderophore transporter in response to low iron concentrations. In addition, multiple other transporters were upregulated, however when desferrioxamine was present, amphibactin production decreased and the ferrioxamine receptor increased in abundance. Such cheating phenotypes, which appear widespread among marine amphibactin producers, highlight the strategies that contribute to the fitness of marine bacteria in the face of iron stress. These results demonstrate siderophore producer and cheater phenotypes and highlight the cellular restructuring which is involved due to competition for iron, that shapes the community structure of marine ecosystems.
Project description:Understanding the bacterial community structure, and their functional analysis for active bioremediation process is essential to design better and cost effective strategies. Microarray analysis enables us to simultaneously study the functional and phylogenetic markers of hundreds of microorganisms which are involved in active bioremediation process in an environment. We have previously described development of a hybrid 60-mer multibacterial microarray platform (BiodegPhyloChip) for profiling the bacterial communities and functional genes simultaneously in environments undergoing active bioremediation process (Pathak et al; Appl Microbiol Biotechnol,Vol. 90, 1739-1754). The present study involved profiling the status of bacterial communities and functional (biodegradation) genes using the developed 60-mer oligonucleotide microarray BiodegPhyloChip at five contaminated hotspots in the state of Gujarat, in western India. The expression pattern of functional genes (coding for key enzymes in active bioremediation process) at these sites was studied to understand the dynamics of biodegradation in the presence of diverse group of chemicals. The results indicated that the nature of pollutants and their abundance greatly influence the structure of bacterial communities and the extent of expression of genes involved in various biodegradation pathways. In addition, site specific factors also play a pivotal role to affect the microbial community structure as was evident from results of 16S rRNA gene profiling of the five contaminated sites, where the community structure varied from one site to another drastically.
2012-12-01 | GSE38004 | GEO
Project description:bacterial diversity in iron sample
Project description:Understanding the bacterial community structure, and their functional analysis for active bioremediation process is essential to design better and cost effective strategies. Microarray analysis enables us to simultaneously study the functional and phylogenetic markers of hundreds of microorganisms which are involved in active bioremediation process in an environment. We have previously described development of a hybrid 60-mer multibacterial microarray platform (BiodegPhyloChip) for profiling the bacterial communities and functional genes simultaneously in environments undergoing active bioremediation process (Pathak et al; Appl Microbiol Biotechnol,Vol. 90, 1739-1754). The present study involved profiling the status of bacterial communities and functional (biodegradation) genes using the developed 60-mer oligonucleotide microarray BiodegPhyloChip at five contaminated hotspots in the state of Gujarat, in western India. The expression pattern of functional genes (coding for key enzymes in active bioremediation process) at these sites was studied to understand the dynamics of biodegradation in the presence of diverse group of chemicals. The results indicated that the nature of pollutants and their abundance greatly influence the structure of bacterial communities and the extent of expression of genes involved in various biodegradation pathways. In addition, site specific factors also play a pivotal role to affect the microbial community structure as was evident from results of 16S rRNA gene profiling of the five contaminated sites, where the community structure varied from one site to another drastically. Agilent one-color CGH experiment and one-color Gene Expresssion expereiment,Organism: Genotypic designed Agilent-17159 Genotypic designed Agilent Multibacterial 8x15k Array , Labeling kits: Agilent Genomic DNA labeling Kit (Part Number: 5190-0453) and Agilent Quick Amp Kit PLUS (Part number: 5190-0442).