Project description:Proteomes of Vibrio sp. 1A01 exponentially growing on various carbon sources as well as on chitin. Chitin samples contain planktonic cells, particle-associated proteins and excreted proteins.
Project description:Isolation and characterization of two recently isolated Novosphingobium oxfordensis sp. nov. and Novosphingobium mississippiensis sp. nov. strains from soil, with LCMS and genome-based investigation of their glycosphingolipid productions
Project description:Although many members of the genus Vibrio are known to inhabit the marine photic zone, an understanding of the influence of light on the molecular physiology of Vibrio spp. has largely been neglected. To begin to characterize the photophysiology of one such Vibrio sp. (Vibrio campbellii ATCC strain BAA-1116) we used microarray-based expression profiling to compare the transcriptomes of illuminated versus dark cell cultures. Specficially, we compared the transcriptomes of wild type V. campbellii (STR) cells that were cultured in M9 minimal salts medium plus glucose under two conditions: (i) after 24 hours of continuous dark and (ii) after a 12 hour dark:12 hour light cycle (white light illumination at 54 µmol photons s-1 m-2). The results revealed a large photostimulon (differential expression of ~20% of the V. campbellii genome; adjusted p value < 0.0001) that surprisingly included ~75% of the type III secretion system (T3SS) genes which were found to be 1.6 – 5.4X more abundant in illuminated cultures. These findings, which were confirmed by quantitative reverse transcription PCR and quantitative membrane proteomics, strongly suggest that the photostimulon of strain BAA-1116 includes the T3SS.
Project description:Although many members of the genus Vibrio are known to inhabit the marine photic zone, an understanding of the influence of light on the molecular physiology of Vibrio spp. has largely been neglected. To begin to characterize the photophysiology of one such Vibrio sp. (Vibrio campbellii ATCC strain BAA-1116) we used microarray-based expression profiling to compare the transcriptomes of illuminated versus dark cell cultures. Specficially, we compared the transcriptomes of wild type V. campbellii (STR) cells that were cultured in M9 minimal salts medium plus glucose under two conditions: (i) after 24 hours of continuous dark and (ii) after a 12 hour dark:12 hour light cycle (white light illumination at 54 M-BM-5mol photons s-1 m-2). The results revealed a large photostimulon (differential expression of ~20% of the V. campbellii genome; adjusted p value < 0.0001) that surprisingly included ~75% of the type III secretion system (T3SS) genes which were found to be 1.6 M-bM-^@M-^S 5.4X more abundant in illuminated cultures. These findings, which were confirmed by quantitative reverse transcription PCR and quantitative membrane proteomics, strongly suggest that the photostimulon of strain BAA-1116 includes the T3SS. Five biological replicates of V. campbellii BAA-1116 (STR) were grown to log phase (200 rpm, 30M-BM-0C, 25 mL M9 minimal salts medium plus glucose in 125 mL baffled Erlenmeyer flasks) under continuous dark for 24 hours or under a 12 hour dark:12 hour light cycle (white light illumination at 54 M-BM-5mol photons s-1 m-2) and total RNA was extracted from 1.0E+9 cells. Messenger RNA was isolated from the total RNA extracts treated with DNase, labeled with biotin, fragmented and hybridized to V. campbellii BAA-1116 whole genome microarrays (520694F, Affymetrix).
Project description:Objectives: determination of transcription start sites in Vibrio harveyi genome and discovery of new transcripts Methods: we performed differential seqencing of total RNA isolated from o.n. control Vibrio harveyi cultures. Sample treatment with Terminator EXonuclease (TEX) allowed differenciation of primary and secondary transcripts, helping in the definition of transcription start sites (TSS) Results: by data-mining RNA-seq data and performing some Northern Blot experiments we were able to detect new putative small-RNAs, along with these results, a more deep analisys of our RNA-seq data will give futher insight into genetic organization of Vibrio harveyi genome to help in its investigation
Project description:We used RNA-seq to determine transcriptional profiles of whole guts or IPCs isolated from guts infected with wild type or type VI secretion system deficient Vibrio cholerae. We found significant differences between guts and progenitor cells infected wild type or type VI secretion system deficient Vibrio cholerae.
Project description:Brown macroalgae holds an enormous potential as a future feedstock because it rapidly forms large biomasses and has high carbohydrate content (35% of its dry weight consists of alginate and mannitol). However, utilization of brown macroalgae by conventional microbial platforms (e.g., Escherichia coli and Saccharomyces cerevisiae) has been limited due to the inability of these platforms to metabolize alginate. Although recent studies engineered them to utilize alginate, their growth rates and metabolic activities are still too low for industrial applications, likely due to the unoptimized expression of multiple xenogeneic genes. Here, we isolated Vibrio sp. dhg, a novel, fast-growing bacterium that has been naturally evolved for efficient alginate assimilation (growth rate = 0.98 h-1). Especially, both the growth rate and sugar uptake rate of V. sp. dhg are substantially higher than the rates of E. coli for most biomass-derivable sugars. Based on our systematic characterization of its metabolism and gene expression architecture, we were able to develop a genetic toolbox for its engineering. By using this microorganism, we successfully demonstrated its ability to produce a broad spectrum of chemicals from alginate-mannitol mixtures with high productivities (1.1 g ethanol/L/h, 1.3 g 2,3-butanediol and acetoin/L/h, and 0.69 mg lycopene/L/h). Collectively, the V. sp. dhg strain is a powerful platform for the conversion of brown macroalgae sugars whose usage will dramatically accelerate the production of value-added biochemicals in the future.
