ABSTRACT: Reduced sulfide and methane in rising main sewer via calcium peroxide dosing: Insights from microbial physiological characteristics, metabolisms and community traits
Project description:Stress response of Methylococcus capsulatus str.Bath toward hydrogen sulfide (H2S) was investigated via physiological study and transcriptomic profiling. M. capsulatus (Bath) can grow and tolerate up to 0.75%vol H2S in headspace. Vast change in pH suggests biological relevant sulfide oxidation. Dozens of H2S-sensitive genes were identified from comparison of cell transcriptome in different H2S concentrations. Mc sulfide quinone reductase (SQR) and persulfide dioxygenase were found to be active during sulfide detoxification. Moreover, xoxF, a novel lanthanide(Ln)-dependent methanol dehydrogenase (MDH) was overexpressed in H2S while mxaF, a calcium-dependent MDH, was down-regulated, and such MDH switch phenomenon is also well known to be induced by addition of lanthanide via an as-yet-unknown mechanism. Activities in quorum sensing and RND efflux pump also suggest their role in sulfide detoxification, and might provide insight on the xoxF/mxaF switch mechanism.
2021-12-24 | GSE192351 | GEO
Project description:Microbial community response to corrosion dosing treatments in sewer
Project description:As one of the most important environmental factors, heat stress (HS) has been found to affect various biological activities of organisms such as growth, signal transmission, primary metabolism and secondary metabolism. Ganoderma lucidum has become a potential model system for evaluating how environmental factors regulate the secondary metabolism of basidiomycetes. Previous research showed that HS can induce the biosynthesis of ganoderic acids (GAs). In this study, we found the existence of hydrogen sulfide in Ganoderma lucidum; moreover, HS increased GAs biosynthesis and could affect the hydrogen sulfide content. We found that sodium hydrosulfide (NaHS), an exogenous donor of hydrogen sulfide, could revert the increased GAs biosynthesis elicited by HS. This result indicated that an increased content of hydrogen sulfide, within limits, was associated with HS-induced GAs biosynthesis. Our results further showed that the GAs content was increased in CBS-silenced strains and could be reverted to WT strain levels by the addition of NaHS. Transcriptomic analyses indicated that that H2S can affect various intracellular signal pathways and physiological processes in G. lucidum. Further studies showed that H2S could affect the intracellular calcium concentration and thus regulate the biosynthesis of GAs. This study demonstrated that hydrogen sulfide is involved in the regulation of secondary metabolic processes induced by heat stress in filamentous fungi.
2021-10-12 | GSE121270 | GEO
Project description:A novel technology employed to control sewer sulfide
Project description:Oxidative Stress Protection and the Repair Response To Hydrogen Peroxide in the Hyperthermophilic Archaeon Pyrococcus furiosus Pyrococcus furiosus is a shallow marine, anaerobic archaeon that grows optimally at 100°C. Addition of H2O2 (0.5 mM) to a growing culture resulted in cessation of growth with a 2 hour lag before normal growth resumed. Whole genome transcriptional profiling revealed that the main response occurs within 30 min of peroxide addition, with the up-regulation of 62 open reading frames (ORFs), 36 of which are part of 10 potential operons. More than half of the up-regulated ORFs are of unknown function while some others encode proteins that are involved potentially in sequestering iron and sulfide, in DNA repair and in generating NADPH. This response is thought to involve primarily damage repair rather than protection, since cultures exposed to sub-toxic levels of H2O2 were not more resistant to the subsequent addition of H2O2 (0.5 – 5.0 mM). Consequently, there is little if any induced protective response to peroxide, rather, the organism maintains a constitutive protective mechanism involving high levels of oxidoreductase-type enzymes such as superoxide reductase, rubrerythrin and alkyl hydroperoxide reductase I. The related hyperthermophiles P. woesei and Thermococcus kodakaraensis were more sensitive to peroxide than P. furiosus, apparently due to the lack of several of its peroxide-responsive ORFs.
2010-02-25 | GSE20470 | GEO
Project description:method for controlling sulfide and methane formation in sewer systems
Project description:Oxidative Stress Protection and the Repair Response To Hydrogen Peroxide in the Hyperthermophilic Archaeon Pyrococcus furiosus Pyrococcus furiosus is a shallow marine, anaerobic archaeon that grows optimally at 100°C. Addition of H2O2 (0.5 mM) to a growing culture resulted in cessation of growth with a 2 hour lag before normal growth resumed. Whole genome transcriptional profiling revealed that the main response occurs within 30 min of peroxide addition, with the up-regulation of 62 open reading frames (ORFs), 36 of which are part of 10 potential operons. More than half of the up-regulated ORFs are of unknown function while some others encode proteins that are involved potentially in sequestering iron and sulfide, in DNA repair and in generating NADPH. This response is thought to involve primarily damage repair rather than protection, since cultures exposed to sub-toxic levels of H2O2 were not more resistant to the subsequent addition of H2O2 (0.5 â 5.0 mM). Consequently, there is little if any induced protective response to peroxide, rather, the organism maintains a constitutive protective mechanism involving high levels of oxidoreductase-type enzymes such as superoxide reductase, rubrerythrin and alkyl hydroperoxide reductase I. The related hyperthermophiles P. woesei and Thermococcus kodakaraensis were more sensitive to peroxide than P. furiosus, apparently due to the lack of several of its peroxide-responsive ORFs. Pyrococcus furiosus (DSM 3638) was grown at 95°C in a 20-liter fermentor using maltose as the carbon and energy source. An exponential-phase culture of P. furiosus that had undergone three successive transfers in the experimental medium was used to inoculate the 20-liter fermentor. The culture was shocked with 0.5 mM of hydrogen peroxide (H2O2) when cell density was in mid-exponential phase (~ 5.0 ´ 107 cells/ml, as determined by direct microscopic cell count). To obtain RNA for microarray and for quantitative PCR (QPCR) analyses, samples (2 liter) were rapidly removed from the fermentor and cooled to 4°C. Total RNA was extracted using acid-phenol and stored at -80°C until needed. A total of 3 biological replicates in triplicate (3 copies on the same slide) was used in the data set.
Project description:Hydrogen sulfide (H2S) is a signaling molecule that regulates essential plant processes, such as autophagy and responses to abiotic stresses. Although there is much information about the processes in which H2S is involved, the mechanism of action of H2S is still unclear. However, the posttranslational modification of cysteine residues, named persulfidation, is the main proposed mechanism. In this study, the role of H2S during drought that allows plant stress adaptation has been analyzed, with the focus on the underlying mechanism. H2S pretreatment before imposing drought on plants significantly improved phenotypic traits and decreased the content of biochemical and molecular drought stress markers. In addition, H2S regulated amino acid metabolism and repressed drought-induced degradation pathways, such as bulk autophagy and protein ubiquitination. The label-free quantitative proteomic analysis of plants growing under control and drought stress identified 887 proteins significantly different persulfidated between both conditions. Bioinformatic analyses revealed that the biological processes most enriched containing the proteins more persulfidated in drought corresponded to cellular response to oxidative stress, and hydrogen peroxide catabolism. In addition, protein degradation, abiotic stress responses, anthocyanin-containing compound biosynthetic process, and flavonoid biosynthesis were highlighted. On the contrary, the most enriched biological process containing proteins with lower levels of persulfidation in drought corresponded to the biosynthetic processes of glucosinolates and chlorophyll. Therefore, our findings emphasize the role of H2S as a promoter of enhanced tolerance to drought, enabling plants to respond more rapidly and efficiently after exposure to drought. Furthermore, the proteomic analysis supports the main role of protein persulfidation as the molecular mechanism of H2S to alleviate ROS accumulation and balance redox homeostasis under drought stress.
Project description:Elevated growth temperatures are negatively affecting crop productivity and increasing yield losses. Root traits associated with improved adaptation to rising temperatures are a promising approach to generate new varieties better suited to face the environmental constrains caused by climate change. In this study, we identified various Brassica napus roots traits altered in response to warm temperature. Thus, different combination of changes in specific root traits results in an extended and deeper root system. This overall root growth expansion facilitates root adaptation by maximizing root-soil surface interaction and increasing its ability to explore extended soil areas. We associated these traits to coordinated cellular events, including changes in cell division and elongation rates, that drive the increase in root growth triggered by warm temperature. Comparative genome wide transcriptomic analysis revealed the main genetic determinants of these RSA changes and uncovered the necessity of a tight regulation of the heat shock stress response to adjust root growth to warm temperature. Our work provides a phenotypic, cellular and genetic framework of root response to warming temperatures that will help to harness root adaptation mechanisms for crop yield improvement under the future climatic scenario.
Project description:Title: Changes in gene expression affected by H2O2 in cardiac myocytes.<br/> Description: We aim to identify the changes in gene expression in response to <br/> oxidative stress in rat neonatal ventricular myocytes.<br/> Oxidative stress will be induced by dosing neonatal ventricular myocyte<br/> cultures with 0.2, 0.1 and 0.04mM hydrogen peroxide at 2, 4 and 8 hr time<br/> points using unstimulated myocytes as control.