Read by QxMD icon Read

Iron reducing bacteria

Svein Rune Erga, Stig Bjarte Haugen, Gunnar Bratbak, Jorun Karin Egge, Mikal Heldal, Kjell Arne Mork, Svein Norland
The aim of this study was to reveal the relative content of C, N, Ca, Si, P, Mg, K, S and Fe in seston particles in Norwegian coastal water (NCW), and how it relates to biological and hydrographic processes during seasonal cycles from October 2009-March 2012. The following over all stoichiometric relationship for the time series was obtained: C66N11Si3.4Ca2.3P1Mg0.73S0.37K0.35Fe0.30, which is novel for marine waters. A record-breaking (187-year record) negative North Atlantic Oscillation (NAO) index caused extreme physical forcing on the Norwegian Coastal Current Water (NCCW) during the winter 2009-2010, and the inflow and upwelling of saline Atlantic water (AW) in the fjord was thus extraordinary during late spring-early summer in 2010...
November 20, 2017: Marine Chemistry
Han-Yueh Kuo, Hsuan-Hao Chao, Po-Cheng Liao, Long Hsu, Kai-Chih Chang, Chi-Hua Tung, Chang-Hua Chen, Ming-Li Liou
The RNA chaperone Hfq is involved in the riboregulation of diverse genes via small RNAs. Recent studies have demonstrated that Hfq contributes to the stress response and the virulence of several pathogens, and the roles of Hfq vary among bacterial species. Here, we attempted to elucidate the role of Hfq in Acinetobacter baumannii ATCC 17978. In the absence of hfq, A. baumannii exhibited retarded cell growth and was highly sensitive to environmental stress, including osmotic and oxidative pressure, pH, and temperature...
2017: Frontiers in Microbiology
Alejandro Negrete, Joseph Shiloach
Efficient growth of E. coli, especially for production of recombinant proteins, has been a challenge for the biotechnological industry since the early 1970s. By employing multiple approaches, such as different media composition, various growth strategies and specific genetic manipulations, it is now possible to grow bacteria to concentrations exceeding 100 g/L and to achieve high concentrations of recombinant proteins. Although the growth conditions are carefully monitored and maintained, it is likely that during the growth process cells are exposed to periodic stress conditions, created by fluctuations in pH, dissolved oxygen, temperature, glucose, and salt concentration...
November 14, 2017: Microbial Cell Factories
Kirti Ranjan Das, Meenal Kowshik, M K Praveen Kumar, Savita Kerkar, S K Shyama, Samir Mishra
A hypersaline dissimilatory sulphate reducing bacterium, strain LS4, isolated from the sediments of Ribander saltpan, Goa, India was found to produce (Fe2O3) maghemite nanoparticles. The presence of maghemite nanoparticles was also detected in the same sediment. Strain LS4 was isolated anaerobically on modified Hatchikian's media at 300 psu, growing optimally at 30 °C, 150 psu salinity and pH 7.8. Based on biochemical characteristics and 16S rRNA sequence analysis, the strain LS4 belongs to genus Desulfovibrio...
November 8, 2017: Journal of Environmental Management
Yuexia Wu, Ligang Xu, Sai Wang, Zhenglu Wang, Jianying Shang, Xiqing Li, Chunmiao Zheng
This study investigated nitrate attenuation in low-permeability sediments (LPS) in a multi-layer aquifer by integrating hydrochemical, isotopic and microbiological molecular techniques in a field site. In the meantime, the overlying high-permeability sediment (HPS) was also examined on the nitrate attenuation for the sake of comparison. Additionally, laboratory flow-through experiments were conducted to assess the overall nitrate reduction rate in the two types of sediment. The δ(15)N-NO3(-) and δ(34)S-SO4(2-) values were more enriched by approximately 37‰ and 15‰ in the LPS than the overlying HPS associated with substantial reductions of the NO3(-) and SO4(2-) concentration, indicating the occurrence of strong bio-reductions in nitrate and sulfate...
November 7, 2017: Science of the Total Environment
Yanping Bao, Chuling Guo, Guining Lu, Xiaoyun Yi, Han Wang, Zhi Dang
Fe(III) hydroxysulfate minerals are secondary minerals commonly found in acid mine drainage (AMD) sites and have a major impact on water and soil quality in these environments. While previous studies showed that the Fe(III) hydroxysulfate mineral transformation could be mediated by some bacterial strains under laboratory conditions, the role of indigenous microbial activity in Fe(III) hydroxysulfate mineral transformation in natural environment has received little attention. In this study, microcosms were constructed with AMD-affected river water and sediment from the Dabaoshan Mine that was either left unamended or enriched with nutrients (lactate, nitrogen, and phosphorus (LNP)) and biosynthetic minerals (schwertmannite or jarosite)...
November 2, 2017: Science of the Total Environment
Franziska Schaedler, Cindy Lockwood, Ulf Lueder, Clemens Glombitza, Andreas Kappler, Caroline Schmidt
Nitrate-reducing iron(II)-oxidizing bacteria have been known for approximately 20 years. There has been much debate to which extent the reduction of nitrate and the oxidation of ferrous iron are coupled via enzymatic pathways or via abiotic processes induced by nitrite formed by heterotrophic denitrification. The aim of the present study was to assess the coupling of nitrate reduction and iron(II) oxidation by monitoring changes in substrate concentrations as well as in the activity of nitrate-reducing bacteria in natural littoral freshwater sediment as a response to a stimulation with nitrate and iron(II)...
November 3, 2017: Applied and Environmental Microbiology
Hong Peng, Yaobin Zhang, Dongmei Tan, Zhiqiang Zhao, Huimin Zhao, Xie Quan
Granular activated carbon (GAC) or magnetite could promote methane production from organic wastes, but their roles in enhancing anaerobic sludge digestion have not been clarified. GAC, magnetite and their combination were complemented into sludge digesters, respectively. Experimental results showed that average methane production increased by 7.3% for magnetite, 13.1% for GAC, and 20% for the combination of magnetite and GAC, and the effluent TCOD of the control, magnetite, GAC and magnetite-GAC digesters on day 56 were 53...
October 20, 2017: Bioresource Technology
Nolwenn Callac, Nicole R Posth, Jayne E Rattray, Kweku K Y Yamoah, Alan Wiech, Magnus Ivarsson, Christoffer Hemmingsson, Stephanos P Kilias, Ariadne Argyraki, Curt Broman, Henrik Skogby, Rienk H Smittenberg, Ernest Chi Fru
The seafloor sediments of Spathi Bay, Milos Island, Greece, are part of the largest arsenic-CO2-rich shallow submarine hydrothermal ecosystem on Earth. Here, white and brown deposits cap chemically distinct sediments with varying hydrothermal influence. All sediments contain abundant genes for autotrophic carbon fixation used in the Calvin-Benson-Bassham (CBB) and reverse tricaboxylic acid (rTCA) cycles. Both forms of RuBisCO, together with ATP citrate lyase genes in the rTCA cycle, increase with distance from the active hydrothermal centres and decrease with sediment depth...
October 31, 2017: Scientific Reports
Shiling Zheng, Bingchen Wang, Fanghua Liu, Oumei Wang
Minerals that contain ferric iron, such as amorphous Fe(III) oxides (A), can inhibit methanogenesis by competitively accepting electrons. In contrast, ferric iron reduced products, such as magnetite (M), can function as electrical conductors to stimulate methanogenesis, however, the processes and effects of magnetite production and transformation in the methanogenic consortia are not yet known. Here we compare the effects on methanogenesis of amorphous Fe (III) oxides (A) and magnetite (M) with ethanol as the electron donor...
November 2017: Journal of Microbiology / the Microbiological Society of Korea
Daniela Paganini, Michael B Zimmermann
In infants and young children in Sub-Saharan Africa, iron-deficiency anemia (IDA) is common, and many complementary foods are low in bioavailable iron. In-home fortification of complementary foods using iron-containing micronutrient powders (MNPs) and oral iron supplementation are both effective strategies to increase iron intakes and reduce IDA at this age. However, these interventions produce large increases in colonic iron because the absorption of their high iron dose (≥12.5 mg) is typically <20%. We reviewed studies in infants and young children on the effects of iron supplements and iron fortification with MNPs on the gut microbiome and diarrhea...
October 25, 2017: American Journal of Clinical Nutrition
Arevik Vardanyan, Nasia Kafa, Viktoras Konstantinidis, Seung Gu Shin, Ioannis Vyrides
Phosphorus (P) and iron mass balance from Limassol Wastewater Treatment Plant showed that the major removal and accumulation occurred at the aerobic secondary stage and at Dewatered Anaerobic Sludge (DWAS), respectively. The purpose of this study was to examine various parameters that effect the P dissolution under low pH from DWAS. The parameters that significantly contribute to P extraction were the exposure to pH 2.5, the anaerobic conditions and the sequential extraction. The addition of chemolithotrophic acidophilic bacteria has negatively influenced P dissolution, whereas the addition of acidophilic Heterotrophic Iron Reducing (HIR) bacteria has slightly increased P dissolution but they contributed to pH maintenance at lower levels compared to no addition of HIR...
October 9, 2017: Bioresource Technology
Seyed Majid Mousavi, Babak Motesharezadeh, Hossein Mirseyed Hosseini, Hoseinali Alikhani, Ali Asghar Zolfaghari
Many studies have conducted to determine the best management practice to reduce the mobility and phytoavailability of the trace metals in contaminated soils. In this study, geochemical speciation and phytoavailability of Zn for sunflower were studied after application of nanoparticles (SiO2 and zeolite, with an application rate of 200 mg kg(-1)) and bacteria [Bacillus safensis FO-036b(T) and Pseudomonas fluorescens p.f.169] to a calcareous heavily contaminated soil. Results showed that the biotic and abiotic treatments significantly reduced the Zn concentration in the aboveground to non-toxicity levels compared to the control treatment, and the nanoparticle treatments were more effective than the bacteria and control treatments...
October 23, 2017: Environmental Geochemistry and Health
Caitlin K Wotanis, William P Brennan, Anthony D Angotti, Elizabeth A Villa, Josiah P Zayner, Alexandra N Mozina, Alexandria C Rutkovsky, Richard C Sobe, Whitney G Bond, Ece Karatan
The polyamine norspermidine is one of the major polyamines synthesized by Vibrionales and has also been found in various aquatic organisms. Norspermidine is among the environmental signals that positively regulate Vibrio cholerae biofilm formation. The NspS/MbaA signaling complex detects extracellular norspermidine and mediates the response to this polyamine. Norspermidine binding to the NspS periplasmic binding protein is thought to inhibit the phosphodiesterase activity of MbaA, increasing levels of the biofilm-promoting second messenger cyclic diguanylate monophosphate, thus enhancing biofilm formation...
2017: PloS One
L M Ward, A Idei, S Terajima, T Kakegawa, W W Fischer, S E McGlynn
Banded iron formations (BIFs) are rock deposits common in the Archean and Paleoproterozoic (and regionally Neoproterozoic) sedimentary successions. Multiple hypotheses for their deposition exist, principally invoking the precipitation of iron via the metabolic activities of oxygenic, photoferrotrophic, and/or aerobic iron-oxidizing bacteria. Some isolated environments support chemistry and mineralogy analogous to processes involved in BIF deposition, and their study can aid in untangling the factors that lead to iron precipitation...
November 2017: Geobiology
Lili Wang, Qiao Li, Yi Li, Xiuyun Sun, Jiansheng Li, Jinyou Shen, Weiqing Han, Lianjun Wang
Waste printed circuit boards (WPCBs) and steel pickling waste liquor (SPWL) have received extensive attention in recent years because of its harmfulness and resource. In this work, two-step leaching process was carried out by using SPWL as the leaching agent. A series of continuously domesticated bacteria were used for bioleaching and the bacterial strain was identified as Acidithiobacillus ferrooxidans (A. ferrooxidans) by 16S rDNA gene sequence analysis. The vast majority of the metals in WPCBs were recovered by two-step leaching, such as Cu, Pb, Zn, Sn, Al, Ni...
October 10, 2017: Waste Management
Ferran Pujol-Vila, Jiri Dietvorst, Laura Gall-Mas, María Díaz-González, Núria Vigués, Jordi Mas, Xavier Muñoz-Berbel
Materials science offers new perspectives in the clinical analysis of antimicrobial sensitivity. However, a biomaterial with the capacity to respond to living bacteria has not been developed to date. We present an electrochromic iron(III)-complexed alginate hydrogel sensitive to bacterial metabolism, here applied to fast antibiotic-susceptibility determination. Bacteria under evaluation are entrapped -and pre-concentrated- in the hydrogel matrix by oxidation of iron (II) ions to iron (III) and in situ formation of the alginate hydrogel in less than 2min and in soft experimental conditions (i...
September 6, 2017: Journal of Colloid and Interface Science
Kimberley L Painter, Alex Hall, Kam Pou Ha, Andrew M Edwards
Small colony variants (SCVs) of Staphylococcus aureus typically lack a functional electron transport chain and cannot produce virulence factors such as leukocidins, hemolysins or the anti-oxidant staphyloxanthin. Despite this, SCVs are associated with persistent infections of the bloodstream, bones and prosthetic devices. The survival of SCVs in the host has been ascribed to intracellular residency, biofilm formation and resistance to antibiotics. However, the ability of SCVs to resist host defences is largely uncharacterised...
October 9, 2017: Infection and Immunity
Katarzyna Skrypnik, Joanna Suliburska
The aim of this review is to present the most recent scientific evidence of interactions between the intestinal microbiota and minerals, and the effect of this interaction on the health of the host. The Web of Science database from the years 2013-2017 on this topic was reviewed. Numerous in vitro studies have shown that iron significantly affects the intestinal microbiota. However, Bifidobacteriaceae are capable of binding iron in the large intestine, thereby limiting the formation of free radicals synthesized in the presence of iron, and thus reducing the risk of colorectal cancer...
October 9, 2017: Journal of the Science of Food and Agriculture
Jeffrey D Kiiskila, Dibyendu Sarkar, Kailey A Feuerstein, Rupali Datta
Acid mine drainage (AMD) is extremely acidic, sulfate-rich effluent from abandoned or active mine sites that also contain elevated levels of heavy metals. Untreated AMD can contaminate surface and groundwater and pose severe ecological risk. Both active and passive methods have been developed for AMD treatment consisting of abiotic and biological techniques. Abiotic techniques are expensive and can create large amounts of secondary wastes. Passive biological treatment mainly consists of aerobic or anaerobic constructed wetlands...
October 8, 2017: Environmental Science and Pollution Research International
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"