Project description:Here, we established a successive Fe0-enhanced microbe system to remove azo dye (a typical organic pollutant) by Shewanella decolorationis S12 (S. decolorationis S12, an effective azo dye degradation bacterium) and examined the gene expression time course (10, 30, 60, and 120 min) in whole genome transcriptional level. Comparing with the treatment without ZVI, approximately 8% genes affiliated with 10 different gene expression profiles in S. decolorationis S12 were significantly changed in 120 min during the ZVI-enhanced microbial azo reduction. Intriguingly, MarR transcriptional factor might play a vital role in regulating ZVI-enhanced azo reduction in the aspect of energy production, iron homeostasis, and detoxification. Further investigation showed that induced [Ni-Fe] H2ase genes (hyaABCDEF) and azoreductase genes (mtrABC-omcA) contributed to ZVI-enhanced energy production, while reduced iron uptake (hmuVCB and feoAB), induced sulfate assimilation (cysPTWA) and cysteine biosynthesis (cysM) related genes were essential to iron homeostasis and detoxification. This study disentangles underlying mechanisms of ZVI-enhanced azo reduction in S. decolorationis S12 and lays a foundation for further optimization of integrated ZVI-microbial system for efficient organic pollution treatment.
Project description:Acetic acid bacteria are obligately aerobic alphaproteobacteria that have a unique ability to incompletely oxidize various alcohols and sugars to organic acids. The ability of these bacteria to incompletely oxidize ethanol to acetate has been historically utilized for vinegar production. The mechanism of switching between incomplete oxidation and assimilatory oxidation and the control of energy and carbon metabolism in acetic acid bacteria are not fully understood. To understand the physiology and molecular biology of acetic acid bacteria better, we determined the draft genome sequence of Acetobacter aceti NBRC 14818, which is the type strain of the genus. Based on this draft genome sequence, the transcriptome profiles in A. aceti cells grown on ethanol, acetate, glucose, or mix of ethanol and glucose was determined by using NimbleGen Prokaryotic Expression array (4x72K).
Project description:Arthrobacter chlorophenolicus A6 is a 4-chlorophenol degrading soil bacterium with high phyllosphere colonization capacity. Till now the genetic basis for the phyllosphere competency of Arthrobacter or other pollutant-degrading bacteria is uncertain. We investigated global gene expression profile of A. chlorophenolicus grown in the phyllosphere of common bean (Phaseolus vulgaris) compared to growth on agar surfaces.
Project description:Phylogenetic, microbiological and comparative genomic analysis was used to examine the diversity among members of the genus Caldicellulosiruptor with an eye towards the capacity of these extremely thermophilic bacteria for degrading the complex carbohydrate content of plant biomass. Seven species from this genus (C. saccharolyticus, C. bescii (formerly Anaerocellum thermophilum), C. hydrothermalis, C. owensensis, C. kronotskyensis, C. lactoaceticus, and C. kristjanssonii) were compared on the basis of 16S rRNA phylogeny and cross-species DNA-DNA hybridization to a whole genome C. saccharolyticus oligonucleotide microarray. Growth physiology of the seven Caldicellulosiruptor species on a range of carbohydrates showed that, while all could be cultivated on acid pre-treated switchgrass, only C. saccharolyticus, C. besci, C. kronotskyensis, and C. lactoaceticus were capable of hydrolyzing Whatman No. 1 filter paper. Two-dimensional gel electrophoresis of the secretomes from cells grown on microcrystalline cellulose revealed that species capable of crystalline cellulose hydrolysis also had diverse secretome fingerprints. The two-dimensional secretome of C. saccharolyticus revealed a prominent S-layer protein that appears to be also indicative of highly cellulolytic Caldicellulosiruptor species, suggesting a possible role in cell-substrate interaction. These growth physiology results were also linked to glycoside hydrolase and carbohydrate-binding module inventories for the seven bacteria, deduced from draft genome sequence information. These preliminary inventories indicated that the absence of a single glycoside hydrolase family and carbohydrate binding motif family appear to be responsible for some Caldicellulosiruptor species’ diminished cellulolytic capabilities. Overall, the genus Caldicellulosiruptor appears to contain more genomic and physiological diversity than previously reported, and is well suited for biomass deconstruction applications. Six dye-flip experiments were conducted using C. saccharolyticus genomic DNA as the reference in each dye-flip, and one of six different Caldicellulosiruptor spp. as a tester in each dye-flip
Project description:Acetic acid bacteria are obligately aerobic alphaproteobacteria that have a unique ability to incompletely oxidize various alcohols and sugars to organic acids. The ability of these bacteria to incompletely oxidize ethanol to acetate has been historically utilized for vinegar production. The mechanism of switching between incomplete oxidation and assimilatory oxidation and the control of energy and carbon metabolism in acetic acid bacteria are not fully understood. To understand the physiology and molecular biology of acetic acid bacteria better, we determined the draft genome sequence of Acetobacter aceti NBRC 14818, which is the type strain of the genus. Based on this draft genome sequence, the transcriptome profiles in A. aceti cells grown on ethanol, acetate, glucose, or mix of ethanol and glucose was determined by using NimbleGen Prokaryotic Expression array (4x72K). Acetobacter aceti NBRC14818 was cultivated in the medium containing ethanol, acetate, glucose, or mix of ethanol and glucose as carbon sources in Erlenmeyer flask with rotary shaking. Total RNA was extracted when optical density at 600 nm was 0.3-0.4. The experiment was performed in duplicate independent cultures.
Project description:We present the draft genome of Nitrospirae bacterium Nbg-4 as a representative of this clade and couple this to in situ protein expression under sulfate-enriched and sulfate-depleted conditions in rice paddy soil. The proteins were extracted from the soil and analysed via LC-MS/MS measurements.