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:Bacterium Sphingomonas glacialis AAP5 isolated from the alpine lake Gossenköllesee contains genes for anoxygenic phototrophy as well as proton-pumping xanthorhodopsin. Here we show that AAP5 expresses xanthorhodopsin when illuminated at temperatures below 16°C. In contrast bacteriochlorophyll-containing reaction centers are expressed between 4 and 22°C in the dark. Thus, cells grown at lower temperature under natural light-dark cycle produced both photosystems. The purified xanthorhodopsin contains carotenoid nostoxanthin serving as an auxiliary antenna and performs the standard photocycle. The xanthorhodopsin-containing cells reduced upon illumination their respiration, increased their ATP synthesis and produced more biomass. This documents that the harvested light energy was utilized in the metabolism, which can represent a competitive advance under carbon-limiting conditions. The presence of Sphingomonas bacteria with dual phototrophy was verified in the metagenomes collected from lake Gossenköllesee. This unique trait may represent a metabolic advantage in alpine lakes where photoheterotrophic organisms facelimited organic substrates, low temperature, and extreme changes in irradiance.
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. A two chip study using total RNA recovered from wild-type and motile strains of Sphingomonas. sp A1 grown in 0.5% alginate medium.
Project description:Welan gum is mainly produced by Sphingomonas sp. ATCC 31555 and has broad applications in industry such as that in cement production. Both carbon and nitrogen sources are essential for welan production. However, how nitrogen sources affect the metabolism and gene transcription of welan remains elusive. Here, we used next-generation sequencing RNA-seq to analyze the transcriptome of Sphingomonas sp. ATCC 31555 in the presence of inorganic or organic nitrogen sources. Enriched gene expression and pathway analysis suggest that organic nitrogen sources significantly enhanced the expression of genes in central metabolic pathways of Sphingomonas sp. ATCC 31555 and those critical for welan synthesis compared to that observed using inorganic nitrogen sources. The present study improves our understanding of the molecular mechanism underlying the use of nitrogen in welan synthesis in Sphingomonas sp., as well as provides an important transcriptome resource for Sphingomonas sp. in relation to nitrogen sources.
Project description:Welan gum is mainly produced by Sphingomonas sp. ATCC 31555 and has broad applications in industry such as that in cement production. Both carbon and nitrogen sources are essential for welan production. However, how nitrogen sources affect the metabolism and gene transcription of welan remains elusive. Here, we used next-generation sequencing RNA-seq to analyze the transcriptome of Sphingomonas sp. ATCC 31555 in the presence of inorganic or organic nitrogen sources. Enriched gene expression and pathway analysis suggest that organic nitrogen sources significantly enhanced the expression of genes in central metabolic pathways of Sphingomonas sp. ATCC 31555 and those critical for welan synthesis compared to that observed using inorganic nitrogen sources. The present study improves our understanding of the molecular mechanism underlying the use of nitrogen in welan synthesis in Sphingomonas sp., as well as provides an important transcriptome resource for Sphingomonas sp. in relation to nitrogen sources. Sphingomonas sp. ATCC 31555 strain (stored in our laboratory) was first seeded in an inoculum medium (20 g/L glucose, 3 g/L yeast extract, 3 g/L malt extract, and 5 g/L fish meal protein peptone, pH 7.0), and then cultured in a fermentation medium containing 40 g/L sucrose, 4.0 g/L nitrogen source, 0.6 g/L KH2PO4, and 0.2 g/L MgSO4.7H2O at 37°C. The nitrogen sources used in the present study were as follows: NaNO3 (4.0 g/L) as inorganic nitrogen (IN), beef extract (4.0 g/L) as organic nitrogen (ON), and NaNO3 (1.5 g/L) + beef extract (2.5 g/L) as complex nitrogen (CN). All cultivations were conducted in flasks with constant rotary shaking at 400â??1,000 rpm and 37°C.
Project description:Investigation of whole genome gene expression level changes in Sphingomonas. sp A1 AlgO-deficient mutant grown on alginate compared with that on yeast extract AlgO is a possble transcriptional factor described in J. Bacteriol. (2000) 182(14):3998-4004 by Momma K, Okamoto M, Mishima Y, Mori S, Hashimoto W, and Murata K. A two chip study using total RNA recovered from two cultures of Sphingomonas. sp A1 AlgO-deficient mutant grown in 0.5% alginate medium and 0.5% yeast extract medium. Each chip measures the expression level of genes from Sphingomonas. sp A1.
Project description:Investigation of whole genome gene expression level changes in Sphingomonas. sp A1 AlgO-deficient mutant grown on alginate compared with that on yeast extract AlgO is a possble transcriptional factor described in J. Bacteriol. (2000) 182(14):3998-4004 by Momma K, Okamoto M, Mishima Y, Mori S, Hashimoto W, and Murata K.
Project description:An aerobic, yellow-pigmented, bacteriochlorophyll a-producing strain, designated AAP5 (=DSM 111157=CCUG 74776), was isolated from the alpine lake Gossenköllesee located in the Tyrolean Alps, Austria. Here, we report its description and polyphasic characterization. Phylogenetic analysis of the 16S rRNA gene showed that strain AAP5 belongs to the bacterial genus Sphingomonas and has the highest pairwise 16S rRNA gene sequence similarity with Sphingomonas glacialis (98.3%), Sphingomonas psychrolutea (96.8%), and Sphingomonas melonis (96.5%). Its genomic DNA G + C content is 65.9%. Further, in silico DNA-DNA hybridization and calculation of the average nucleotide identity speaks for the close phylogenetic relationship of AAP5 and Sphingomonas glacialis. The high percentage (76.2%) of shared orthologous gene clusters between strain AAP5 and Sphingomonas paucimobilis NCTC 11030T, the type species of the genus, supports the classification of the two strains into the same genus. Strain AAP5 was found to contain C18:1ω7c (64.6%) as a predominant fatty acid (>10%) and the polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, six unidentified glycolipids, one unidentified phospholipid, and two unidentified lipids. The main respiratory quinone was ubiquinone-10. Strain AAP5 is a facultative photoheterotroph containing type-2 photosynthetic reaction centers and, in addition, contains a xathorhodopsin gene. No CO2-fixation pathways were found.
Project description:This study examines genome-wide expression of the phenanthrene-degrading Sphingomonas sp. LH128 as a response to short-term starvation stress. For this purpose, the strain was subjected to complete nutrient starvation for 4h after growth on a rich medium. Survival was monitored by plating and transcriptomic response was determined by whole-genome microarray analysis. The data showed no major differences were obsrved in gene expression and the viability of the cells were not affected during short-term incubation time