Molecular biological enhancement of coal biodesulfurization. Seventh quarter report, May--July 1990

Energy Technology Data Exchange (ETDEWEB)

Kilbane, J.J.; Bielaga, B.A.

1990-07-01

The overall objective of this project is to sue molecular genetics to develop strains of bacteria with enhanced ability to remove sulfur from coal and to obtain data that will allow the performance and economics of a coal biodesulfurization process to be predicted. The work planned for the current quarter (May 1990 to July 1990) includes the following activities: (1) Construct a cloning vector that can be used in Rhodococcus rhodochrous IGTS8 from the small cryptic plasmid found in Rhodococcus rhodochrous ATCC 190607; (2) Develop techniques for the genetic analysis of IGTS8; (3) Continue biochemical experiments, particularly those that may allow the identification of desulfurization-related enzymes; (4) Continue experiments with coal to determine the kinetics of organic sulfur removal.

PERFORMANCE OF A BIOTRICKLING FILTER EMPLOYING THIOBACILLUS THIOPARUS IMMOBILIZED ON POLYURETHANE FOAM FOR HYDROGEN SULFIDE REMOVAL

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N. Abdehagh

2011-09-01

Full Text Available The removal of hydrogen sulfide (H2S from contaminated airstream was studied in a biotrickling filter (BTF packed with open-pore polyurethane foam as a carrier of Thiobacillus thioparus (DSMZ5368 with counter current gas/liquid flows. The effect of operating parameters on BTF performance was studied. Experiments were performed at different Empty Bed Residence Times (EBRT from 9 to 45 seconds, and different initial H2S concentration from 25 to 85 ppm. The results showed reasonable performance of the BTF, in H2S removal from the synthetic gas stream. However, the performance was somewhat lower than other studies in BTF in which either Thiobacillus thioparus with other packings or polyurethane foam with other microbial cultures were used. The effect of liquid recirculation rate (LRR in the range of 175-525 ml/min (0.46-1.34 m/h on BTF performance was also studied. Results showed that increasing LRR from 175 to 350 mL/min resulted in significant enhancement of H2S removal efficiency, but further increase in LRR up to 525 mL/min had an insignificant effect. H2S elimination at different heights of the bed was studied and it was found that decrease in EBRT results in more homogeneous removal of the pollutant in BTF. Determination of microbial species in the BTF after 100 days performance showed that during BTF operation the only H2S degrading specie was Thiobacillus thioparus.

Enhancement of dibenzothiophene biodesulfurization using {beta}-cyclodextrins in oil-to-water media

Energy Technology Data Exchange (ETDEWEB)

Ainhoa Caro; Pedro Leton; Eloy Garcia-Calvo; Leonardo Setti [Universidad de Alcala, Madrid (Spain). Departamento de Quimica Analitica e Ingeniera Quimica

2007-11-15

It has been reported that biodesulfurization (BDS) of dibenzothiophene (DBT) in oil-to-water emulsions is carried out by growing cells of the aerobic Rhodococcus erythropolis IGTS8 strain and developing the so-called 4S desulfurization pathway. On adding {beta}-cyclodextrins, it is possible to improve the BDS yields, increase the diffusion of DBT into the aqueous phase or avoid the HBP accumulation. Moreover, by using greater biocatalyst initial concentrations and adding 15 ppm of {beta}-cyclodextrin, a very high BDS yield has been observed, but the presence of mass transfer limitations and the inhibition effects were not satisfactorily avoided. The Haldane kinetic model agreed well with the experimental results obtained, and the values of the kinetic parameters were determined. Short communication. 20 refs., 2 figs., 2 tabs.

Co-Inoculation Effects of Thiobacillus thiooxidans Bacteria and Mycorrhiza (Glomus spp. on Maize Nutrition at Different Levels of Sulfur

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A. Gholami

2016-02-01

Full Text Available Introduction: Sulfur is the key element for higher crops and plays an important role in the formation of proteins, vitamins, and enzymes. It is a constituent of amino acids such as cysteine and methionine, which act for the synthesis of other compounds containing reduced sulfur, such as chlorophyll and utilization of phosphorus and otheressential nutrients.Deficiency of this nutrient in soil is usually compensated by using chemical fertilizers. However, these fertilizers have harmful effects on the environment and decrease the quality of the agriculture products. Therefore, biological fertilizers are more useful for using in agricultural ecosystems.Sulfurshould be addedto the soil, usually in a reduced form such as elemental sulfur. Use of S oxidizers enhances the rate of natural oxidation of S and speeds up the production of sulfates and makes them available to plants consequently resulting in an increased plant yield. The role of chemolithotrophic bacteria of the genus Thiobacillus through oxidation process in the soil is usually emphasized. Sulfur oxidation is the most important step of sulfur cycle, which improves soil fertility. The result is formation of sulfate, which can be used by the plants, while the acidity produced by oxidation helps to solubilize nutrients in alkaline soils. These bacteria can solubilise the soil minerals through the production of H2SO4 that reacts with these non-soluble minerals and oxidised them to be available nutrients to the cultivated plants. Arbuscular MycorrhizalFungi isan important component ofthe microbiota, mutualistic symbioticsoilfungithatcolonizesthe rootsofmost cropplants.The AM symbiosis involves an about 80% of land plant species and 92% of plant families. They have theability to enhance host uptake of relativelyimmobile nutrientsparticularly phosphorus (P andzinc (Zn,Manganese (Mn andiron(Fe.Arbuscular mycorrhizal fungi increased plant uptake of phosphorus, nitrogen and water absorption

Bio-desulfurization technology in Japan; Wagakuni ni okeru baio datsuryu gijutsu

Energy Technology Data Exchange (ETDEWEB)

Maruhashi, K. [Petroleum Energy Center, Tokyo (Japan)

2000-05-01

A bio-reaction of microbes (catalytic reaction by an enzyme) is characterized in that the reaction is carried out at a normal temperature and under a normal pressure and has particularly high specificity with respect to substrate (reactant). It is considered that a low loading process of environment harmony type can be constructed by applying the bio-reaction in petroleum refinery process. CO{sub 2} exhaust and energy consumption in the bio-desulfurization (BDS) is estimated to be 70 to 80% lower than those in hydrodesulfurization (HDS). The bio-technologies that can be applied to the petroleum refinery process include, for example, desulfurization, demetallation, dewaxing, denitration, cracking and so on. In this paper, the present state of bio-desulphurization technology is introduced. Particularly, as the research results in Japan, acquirement of mesophile R.erythropolis KA2-5-1 strain, thermophile Paenibacillus sp. A11-2 strain whose optimum temperature is 50 degrees C, BT degradation fungus Rhodococcus sp. T09 and the like are introduced. (NEDO)

Specific dot-immunobinding assay for detection and enumeration of Thiobacillus ferrooxidans

International Nuclear Information System (INIS)

Arredondo, R.; Jerez, C.A.

1989-01-01

A specific and very sensitive dot-immunobinding assay for the detection and enumeration of the bioleaching microorganism Thiobacillus ferrooxidans was developed. Nitrocellulose spotted with samples was incubated with polyclonal antisera against whole T. ferrooxidans cells and then in 125 I-labeled protein A or 125 I-labeled goat antirabbit immunoglobulin G; incubation was followed by autoradiography. Since a minimum of 10 3 cells per dot could be detected, the method offers the possibility of simultaneous processing of numerous samples in a short time to monitor the levels of T. ferrooxidans in bioleaching operations

Evaluation of Thiobacillus Bacteria and Mycorrhizal Symbiosis on Yield and Yield Components of Garlic (Allium sativum at Different Levels of Sulfur

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parvin Hejazi rad

2017-09-01

Full Text Available Introduction Most researchers believe that good management and proper use of biofertilizers are the ways for preparation of better nutritional conditions for the medicinal plant. Garlic is one of the most important medicinal crops. Allicin is the main active ingredient in this plant. Biofertilizers contain beneficial soil microorganisms or the metabolic products. Mycorrhizal symbiosis improves the soil physical, chemical and biological properties. Mycorrhizae increase crop resistance to pathogens, nutrient and water uptake, also reduce the negative effects of environmental stress and improve the quality of their host plants. Adding sulfur to the soil to improve the nutritional status of the plant by the release of nutrients will be effective when that the oxidation of sulfur in the soil is significant. For sulfur uptake by the plant, it is necessary that this element convert to sulfate by soil microorganisms. If elemental sulfur distribute in the soil and mix with the organic material, conversion of sulfur-oxidizing microorganisms be faster in wet conditions. Materials and methods The experiment was conducted as randomized complete block design with three replications in 2012. Treatments were included control plot, mycorrhizal inoculation (M, Thiobacillus (T, M + T, 75 kg sulfur per hectare (75S, 75S + M, 75S + T, 75S + M + T, 150 kg sulfur per hectare (150S, 150S + M, 150S + T, 150S + M + T. Each plot consisted of four rows with a spacing of 40 cm and row length of 10 m. In treatments with 75 and 150 kg sulfur per hectare, 48 and 96 g of sulfur were used, respectively. Thiobacillus at the recommended dose was added to the soil a week before planting. Percent of fungal colonization obtained with Gridline Intersect Method. HPLC method was used to extract allicin content. Data were analyzed with the MSTAT-C software; the means were compared with LSD test at the 5% level of probability. Results and discussion The results showed that tuber dry

Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

OpenAIRE

Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

1984-01-01

Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds.

Ferrous Iron Oxidation by Thiobacillus ferrooxidans: Inhibition with Benzoic Acid, Sorbic Acid, and Sodium Lauryl Sulfate

Science.gov (United States)

Onysko, Steven J.; Kleinmann, Robert L. P.; Erickson, Patricia M.

1984-01-01

Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds. PMID:16346592

Biodesulfurization of coals of different rank: Effect on combustion behavior

Energy Technology Data Exchange (ETDEWEB)

Rubiera, F.; Arenillas, A.; Fuente, E.; Pis, J.J. [CSIC, Oviedo (Spain). Inst. Nacional del Carbon; Marteinz, O.; Moran, A. [Univ. de Leon (Spain). Escuela de Ingenieria Tecnica Minera

1999-02-01

The emission of sulfur oxides during the combustion of coal is one of the causes, among other air pollution problems, of acid rain. The contribution of coal as the mainstay of power production will be determined by whether its environmental performance is equal or superior to other supply options. In this context, desulfurization of coal before combustion by biological methods was studied. Four Spanish high-sulfur content coals of different rank were inoculated with bacteria isolated from mine-drainage waters and with naturally occurring bacteria inherent in the coals to be treated. Higher levels of desulfurization were obtained in the case of the samples treated with their own accompanying bacteria and when aeration was increased. All the samples were amenable to the biodepyritization processes. However, it is of little value to achieve large sulfur reductions if a decrease in coal combustion performance is obtained in the process. For this reason, a comparison was made between the combustibility characteristics of the original coals and those of the biodesulfurized samples. Results indicated that combustibility was not substantially modified by the overall biological treatment. The benefits of reduced sulfur emissions into the atmosphere ought to be taken into account as part of the general evaluation of the processes.

Genetic manipulation of the obligate chemolithoautotrophic bacterium Thiobacillus denitrificans

Energy Technology Data Exchange (ETDEWEB)

Beller, H.R.; Legler, T.C.; Kane, S.R.

2011-07-15

Chemolithoautotrophic bacteria can be of industrial and environmental importance, but they present a challenge for systems biology studies, as their central metabolism deviates from that of model organisms and there is a much less extensive experimental basis for their gene annotation than for typical organoheterotrophs. For microbes with sequenced genomes but unconventional metabolism, the ability to create knockout mutations can be a powerful tool for functional genomics and thereby render an organism more amenable to systems biology approaches. In this chapter, we describe a genetic system for Thiobacillus denitrificans, with which insertion mutations can be introduced by homologous recombination and complemented in trans. Insertion mutations are generated by in vitro transposition, the mutated genes are amplified by the PCR, and the amplicons are introduced into T. denitrificans by electroporation. Use of a complementation vector, pTL2, based on the IncP plasmid pRR10 is also addressed.

Work within the coordinated programme on bacterial leaching of uranium ores. Immunological identification of Thiobacillus ferrooxidans and Thiobacillus thiooxidans

International Nuclear Information System (INIS)

Rhee, K.S.

1978-04-01

Little is known of the antigenic structure of Thiobacillus. In the composition of the antigens of gram negative bacteria the polysaccharide moiety endows some specificity permitting immunological identification. The report considers work on attempts to isolate the type specific component from T. thiooxidans and T ferrooxidans. The fractionation procedures presented suggest that the presence of one or a few such type specific major protein antigen fractions from both of the T. ferrooxidans and the T. thiooxidans seems to be originated from the cytoplasm of the bacteria, since it is believed that the glycoprotein fractions which was derived from the cell wall are the common antigenic fraction between the T. ferrooxidans and the T. thiooxidans, respectively. In this regard, it is of great interest that the T. ferrooxidans or the T. thiooxidans appears not to have the type-specific antigens on their LPS or polysaccharide moiety in contrast to the other gram-negative bacteria. Thus, it is strongly believed that the envelopes of these bacteria contain both glycoproteins bearing common antigenicity, since the T. ferrooxidans and the T. thiooxidans have a structually different type-specific antigen moiety according to the results polyacrylamide gel electrophoresis

Effect of Vermicompost, Sulfur and Thiobacillus on Some Soil Physico-chemical Properties, Yield and Yield Components of Maize (Zea mays L. in Jovain District

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Mahmmud Ahmadi

2018-02-01

Full Text Available Introduction The excessive use of chemical fertilizers causes environmental pollution that is led to imbalance of essential elements in agricultural production system. Organic matter application as compost in the soil can improve chemical quality and biochemical properties that increase essential elements for plant nutrition. Application of organic manure can significantly increase the soil aggregate as well. Reported that application of 7 ton ha-1 of vermicompost increased number of leaves, stem dry weight, and corn plant height as compared to control and water holding capacity increases. Sulphur in plant is near to phosphorus (0.2%. Sulphur deficiency cause severe reduction in plant growth and due to participation in protein building and its deficiency cause yellowish in younger leaves. Sulphur can be applied as elemental sulphur, with ammonium and super phosphate to the soil. Iran is situated in arid and semi arid region of the world and need to reduce the pH with sulphur application due to high pH above 8 in some parts. The aim of this research was to study the effect of above factors in yield and yield components of maize and reducing environmental pollution. Materials and Methods This research carried out at 2012 in Jovein Distract suberb of Sabzevar city. Before conducting the research soil sample were collected from 0-30 cm depth and physical and chemical properties of the soil were estimated. Treatments including sulphur, thiobacillus and vermicompost were applied to soil and well mixed with soil before sowing. Each plot consists of five rows with six m length by 80 cm from each other. Seeds were sown at the depth of five cm and 20 cm from each other. This research carried out as a factorial experiment on the basis of randomized complete block design. In this research three factors including elemental sulphur, vermicompost and thiobacillus were used with three replications. Elemental sulphur in three levels (control, 500 kg ha-1 and

Growth of Thiobacillus ferrooxidans on elemental sulfur

International Nuclear Information System (INIS)

Espejo, R.T.; Romero, P.

1987-01-01

Growth kinetics of Thiobacillus ferrooxidans in batch cultures, containing prills of elementary sulfur as the sole energy source, were studied by measuring the incorporation of radioactive phosphorus in free and adsorbed bacteria. The data obtained indicate an initial exponential growth of the attached bacteria until saturation of the susceptible surface was reached, followed by a linear release of free bacteria due to successive replication of a constant number of adsorbed bacteria. These adsorbed bacteria could continue replication provided the colonized prills were transferred to fresh medium each time the stationary phase was reached. The bacteria released from the prills were unable to multiply, and in the medium employed they lost viability with a half-live of 3.5 days. The spreading of the progeny on the surface was followed by staining the bacteria on the prills with crystal violet; this spreading was not uniform but seemed to proceed through distortions present in the surface. The specific growth rate of T. ferrooxidans ATCC 19859 was about 0.5 day -1 , both before and after saturation of the sulfur surface. The growth of adsorbed and free bacteria in medium containing both ferrous iron and elementary sulfur indicated that T. ferrooxidans can simultaneously utilize both energy sources

Evaluation of the Effect of Sulfur Application and Thiobacillus on Some Soil Chemical Characteristics and Yield of Canola in Wheat-Canola Rotation System

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H. Besharati

2016-09-01

Full Text Available Introduction: After soybean and palm oil, canola is third important oil seed in the world which belongs to the genus Brassicaceae, that its seeds contain about 40% oil. The per capita consumption of oil in Iran is about 14 kg, so approximately 900 thousand tons of oil will be required for each year. However, only less than 10% of this oil is produced in the country. In recent years, special attention has been paid to canola cultivation in order to increase oil production, so during recent years an apparent increase in canola cultivated lands is significant. In most of these canola cultivated lands, the soil is calcareous therefore; some available nutrients such as phosphorus, iron and zinc are less than the amounts required by plants. Increasing qualitative and quantitative yield of canola in calcareous soils is a priority to canola cultivation improvement. Sulfur plays an important role in oil content of oily seed crops. On the other hands sulfur oxidation in calcareous soils can improve some nutrients availability. The present study was designed to investigate the effect of sulfur on yield, oil content and nutrients uptake and also its impact on soil chemical properties with 8 treatments, in 3 replications. Materials and Methods: This study was conducted in Ekbatan research station in Hamedan province for 2 years as completely randomized block design with 8 treatments and 3 repetitions. The treatments were: T1: Control (Without sulfur and Thiobacillus, T2: Application of 150 kg sulfur per ha, T3: T2+ Thiobacillus inoculums (2% of applied sulfur, T4: Application of 300 kg sulfur per ha, T5: T4+ Thiobacillus inoculums (2% of applied sulfur, T6: Application of 600 kg sulfur per ha, T7: T6+ Thiobacillus inoculums (2% of applied sulfur T8: Fertilizing based on soil test without sulfur and Thiobacillus. Thiobacillus inoculant containing about 107 cells of Thiobacillus bacteria which belonged to neutrophile Thiobacilli were prepared at soil biology

Short communication: Adverse effect of surface-active reagents on the bioleaching of pyrite and chalcopyrite by Thiobacillus ferrooxidans.

Science.gov (United States)

Huerta, G; Escobar, B; Rubio, J; Badilla-Ohlbaum, R

1995-09-01

Oxidation of Fe(II) iron and bioleaching of pyrite and chalcopyrite by Thiobacillus ferrooxidans was adversely affected by isopropylxanthate, a flotation agent, and by LIX 984, a solvent-extraction agent, each at ≤ 1 g/l. The reagents/l were adsorbed on the bacterial surface, decreasing the bacteria's development and preventing biooxidation. Both reagents inhibited the bioleaching of pyrite and LIX 984 also inhibited the bioleaching of chalcopyrite.

A novel Bacillus pumilus-related strain from tropical landfarm soil is capable of rapid dibenzothiophene degradation and biodesulfurization.

Science.gov (United States)

Buzanello, Elizandra Bruschi; Rezende, Rachel Passos; Sousa, Fernanda Maria Oliveira; Marques, Eric de Lima Silva; Loguercio, Leandro Lopes

2014-10-08

The presence of organic sulfur-containing compounds in the environment is harmful to animals and human health. The combustion of these compounds in fossil fuels tends to release sulfur dioxide in the atmosphere, which leads to acid rain, corrosion, damage to crops, and an array of other problems. The process of biodesulfurization rationally exploits the ability of certain microorganisms in the removal of sulfur prior to fuel burning, without loss of calorific value. In this sense, we hypothesized that bacterial isolates from tropical landfarm soils can demonstrate the ability to degrade dibenzothiophene (DBT), the major sulfur-containing compound present in fuels. Nine bacterial isolates previously obtained from a tropical landfarm soil were tested for their ability to degrade dibenzothiophene (DBT). An isolate labeled as RR-3 has shown the best performance and was further characterized in the present study. Based on physiological aspects and 16 s rDNA sequencing, this isolate was found to be very closely related to the Bacillus pumillus species. During its growth, high levels of DBT were removed in the first 24 hours, and a rapid DBT degradation within the first hour of incubation was observed when resting cells were used. Detection of 2-hydroxybiphenyl (HBP), a marker for the 4S pathway, suggests this strain has metabolical capability for DBT desulfurization. The presence of MgSO4 in growth medium as an additional sulfur source has interfered with DBT degradation. To our knowledge, this is the first study showing that a Bacillus strain can metabolize DBT via the 4S pathway. However, further evidences suggest RR-3 can also use DBT (and/or its derivative metabolites) as carbon/sulfur source through another type of metabolism. Compared to other reported DBT-degrading strains, the RR-3 isolate showed the highest capacity for DBT degradation ever described in quantitative terms. The potential application of this isolate for the biodesulfurization of this sulfur

A novel mineral flotation process using Thiobacillus ferrooxidans.

Science.gov (United States)

Nagaoka, T; Ohmura, N; Saiki, H

1999-08-01

Oxidative leaching of metals by Thiobacillus ferrooxidans has proven useful in mineral processing. Here, we report on a new use for T. ferrooxidans, in which bacterial adhesion is used to remove pyrite from mixtures of sulfide minerals during flotation. Under control conditions, the floatabilities of five sulfide minerals tested (pyrite, chalcocite, molybdenite, millerite, and galena) ranged from 90 to 99%. Upon addition of T. ferrooxidans, the floatability of pyrite was significantly suppressed to less than 20%. In contrast, addition of the bacterium had little effect on the floatabilities of the other minerals, even when they were present in relatively large quantities: their floatabilities remained in the range of 81 to 98%. T. ferrooxidans thus appears to selectively suppress pyrite floatability. As a consequence, 77 to 95% of pyrite was removed from mineral mixtures while 72 to 100% of nonpyrite sulfide minerals was recovered. The suppression of pyrite floatability was caused by bacterial adhesion to pyrite surfaces. When normalized to the mineral surface area, the number of cells adhering to pyrite was significantly larger than the number adhering to other minerals. These results suggest that flotation with T. ferrooxidans may provide a novel approach to mineral processing in which the biological functions involved in cell adhesion play a key role in the separation of minerals.

Influence oFe3+ Ions on Nitrate Removal by Autotrophic Denitrification Using Thiobacillus denitrificans

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Z. Blažková

2017-07-01

Full Text Available he sulphur-based autotrophic denitrification process utilizing Thiobacillus denitrificans was studied experimentally as an alternative method of removing nitrates from industrial wastewater. The objective of the work was to examine the effect of ferric iron addition to the reaction mixture and determine optimal dosage for specific conditions. All experiments were carried out in anoxic batch bioreactor, and elemental sulphur was used as an electron donor. Compared to the control operation without ferric iron addition, significant increases in nitrates removal were demonstrated for the concentration of ferric iron equal to 0.1 mg L–1. However, under these conditions, increased nitrite content was detected in the reaction mixture which exceeds the limits for drinking water.

Mathematical model of the oxidation of ferrous iron by a biofilm of Thiobacillus ferrooxidans.

Science.gov (United States)

Mesa, M M; Macías, M; Cantero, D

2002-01-01

Microbial oxidation of ferrous iron may be a viable alternative method of producing ferric sulfate, which is a reagent used for removal of H(2)S from biogas. The paper introduces a kinetic study of the biological oxidation of ferrous iron by Thiobacillus ferrooxidans immobilized on biomass support particles (BSP) composed of polyurethane foam. On the basis of the data obtained, a mathematical model for the bioreactor was subsequently developed. In the model described here, the microorganisms adhere by reversible physical adsorption to the ferric precipitates that are formed on the BSP. The model can also be considered as an expression for the erosion of microorganisms immobilized due to the agitation of the medium by aeration.

Kinetic properties of ATP sulfurylase and APS kinase from Thiobacillus denitrificans.

Science.gov (United States)

Gay, Sean C; Fribourgh, Jennifer L; Donohoue, Paul D; Segel, Irwin H; Fisher, Andrew J

2009-09-01

The Thiobacillus denitrificans genome contains two sequences corresponding to ATP sulfurylase (Tbd_0210 and Tbd_0874). Both genes were cloned and expressed protein characterized. The larger protein (Tbd_0210; 544 residues) possesses an N-terminal ATP sulfurylase domain and a C-terminal APS kinase domain and was therefore annotated as a bifunctional enzyme. But, the protein was not bifunctional because it lacked ATP sulfurylase activity. However, the enzyme did possess APS kinase activity and displayed substrate inhibition by APS. Truncated protein missing the N-terminal domain had APS kinase activity suggesting the function of the inactive sulfurylase domain is to promote the oligomerization of the APS kinase domains. The smaller gene product (Tbd_0874; 402 residues) possessed strong ATP sulfurylase activity with kinetic properties that appear to be kinetically optimized for the direction of APS utilization and ATP+sulfate production, which is consistent with an enzyme that functions physiologically to produce inorganic sulfate.

Metabolic and process engineering for biodesulfurization in Gram-negative bacteria.

Science.gov (United States)

Martínez, I; El-Said Mohamed, M; Santos, V E; García, J L; García-Ochoa, F; Díaz, E

2017-11-20

Microbial desulfurization or biodesulfurization (BDS) is an attractive low-cost and environmentally friendly complementary technology to the hydrotreating chemical process based on the potential of certain bacteria to specifically remove sulfur from S-heterocyclic compounds of crude fuels that are recalcitrant to the chemical treatments. The 4S or Dsz sulfur specific pathway for dibenzothiophene (DBT) and alkyl-substituted DBTs, widely used as model S-heterocyclic compounds, has been extensively studied at the physiological, biochemical and genetic levels mainly in Gram-positive bacteria. Nevertheless, several Gram-negative bacteria have been also used in BDS because they are endowed with some properties, e.g., broad metabolic versatility and easy genetic and genomic manipulation, that make them suitable chassis for systems metabolic engineering strategies. A high number of recombinant bacteria, many of which are Pseudomonas strains, have been constructed to overcome the major bottlenecks of the desulfurization process, i.e., expression of the dsz operon, activity of the Dsz enzymes, retro-inhibition of the Dsz pathway, availability of reducing power, uptake-secretion of substrate and intermediates, tolerance to organic solvents and metals, and other host-specific limitations. However, to attain a BDS process with industrial applicability, it is necessary to apply all the knowledge and advances achieved at the genetic and metabolic levels to the process engineering level, i.e., kinetic modelling, scale-up of biphasic systems, enhancing mass transfer rates, biocatalyst separation, etc. The production of high-added value products derived from the organosulfur material present in oil can be regarded also as an economically viable process that has barely begun to be explored. Copyright © 2017 Elsevier B.V. All rights reserved.

Structure/function relationship of the rusticyanin among thiobacillus ferroxidans: from the fermenter to the crystal; Relations structure/fonction de la rusticyanine chez thiobacillus ferrooxidans: du fermenteur au cristal

Energy Technology Data Exchange (ETDEWEB)

Nunzi, F.

1996-09-23

The commercial extraction of copper and uranium from ores by microbial leaching turns to account the iron oxidation capacity of Thiobacillus ferroxidans. The iron oxidation involves an electron transport chain localized in the peri-plasmic space of the cell. The aim of our work is to study the structure-function relationships of rusticyanin, the most important component of this respiratory chain. Rusticyanin is a blue copper protein and has been characterized from a new strain of Thilbacillus ferrooxidans. A preliminary electrochemical study has been made with a new modified-gold electrode and we have examined, in particular, the pH dependence of the high redox potential of rusticyanin. Its amino acid sequence has been determined and a comparison with two other rusticyanin sequences, isolated from different strains, shows a high degree of homology. A structural alignment with six other blue copper proteins allows to propose four residues as copper ligands, His 84, Cys 138, His 143 and Met 148. The supposed factors responsible for the high redox potential of rusticyanin are discussed. (author)

Improvement of Biodesulfurization Rate of Alginate Immobilized Rhodococcus erythropolis R1.

Science.gov (United States)

Derikvand, Peyman; Etemadifar, Zahra

2014-03-01

Sulfur oxides released from the burning of oil causes severe environmental pollution. The sulfur can be removed via the 4S pathway in biodesulfurization (BDS). Immobilization approaches have been developed to prevent cell contamination of oil during the BDS process. The encapsulation of Rhodococcus erythropolis R1 in calcium alginate beads was studied in order to enhance conversion of dibenzothiophene (DBT) to 2-hydroxy biphenyl (2-HBP) as the final product. Also the effect of different factors on the BDS process was investigated. Calcium alginate capsules were prepared using peristaltic pumps with different needle sizes to control the beads sizes. Scanning electron microscopy and flow cytometry methods were used to study the distribution and viability of encapsulated cells, respectively. Two non-ionic surfactants and also nano Ƴ-Al2O3were used with the ratio of 0.5% (v/v) and 1:5 (v/v) respectively to investigate their BDS efficiency. In addition, the effect of different bead sizes and different concentrations of sodium alginate in BDS activity was studied. The 2% (w/v) sodium alginate beads with 1.5mm size were found to be the optimum for beads stability and efficient 2-HBP production. The viability of encapsulated cells decreased by 12% after 20 h of desulfurization, compared to free cells. Adding the non-ionic surfactants markedly enhanced the rate of BDS, because of increasing mass transfer of DBT to the gel matrix. In addition, Span 80 was more effective than Tween 80. The nanoƳ-Al2O3 particles could increase BDS rate by up to two-folds greater than that of the control beads. The nano Ƴ-Al2O3 can improve the immobilized biocatalyst for excellent efficiency of DBT desulfurization. Also the BDS activity can be enhanced by setting the other explained factors at optimum levels.

Selection and Application of Sulfide Oxidizing Microorganisms Able to Withstand Thiols in Gas Biodesulfurization Systems.

Science.gov (United States)

Roman, Pawel; Klok, Johannes B M; Sousa, João A B; Broman, Elias; Dopson, Mark; Van Zessen, Erik; Bijmans, Martijn F M; Sorokin, Dimitry Y; Janssen, Albert J H

2016-12-06

After the first commercial applications of a new biological process for the removal of hydrogen sulfide (H 2 S) from low pressure biogas, the need arose to broaden the operating window to also enable the removal of organosulfur compounds from high pressure sour gases. In this study we have selected microorganisms from a full-scale biodesulfurization system that are capable of withstanding the presence of thiols. This full-scale unit has been in stable operation for more than 10 years. We investigated the microbial community by using high-throughput sequencing of 16S rRNA gene amplicons which showed that methanethiol gave a competitive advantage to bacteria belonging to the genera Thioalkalibacter (Halothiobacillaceae family) and Alkalilimnicola (Ectothiorhosdospiraceae family). The sulfide-oxidizing potential of the acclimatized population was investigated under elevated thiol loading rates (4.5-9.1 mM d -1 ), consisting of a mix of methanethiol, ethanethiol, and propanethiol. With this biomass, it was possible to achieve a stable bioreactor operation at which 80% of the supplied H 2 S (61 mM d -1 ) was biologically oxidized to elemental sulfur. The remainder was chemically produced thiosulfate. Moreover, we found that a conventionally applied method for controlling the oxygen supply to the bioreactor, that is, by maintaining a redox potential set-point value, appeared to be ineffective in the presence of thiols.

Evaluating Maize Yield and the Quality of Response to Vermicompost, in Thiobacillus and Foliar Application of Fe and Zn

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Elnaz Davaran Hagh

2017-08-01

Full Text Available Introduction Half of the world's population suffers from micronutrients malnutrition. Use of bio-fertilizers in sustainable agricultural systems is important in production and enables plants to absorb more water from soil and improves plant nutrient uptake and photosynthesis. Benefits of vermicompost application in agriculture is due to its content of organic matter, plant nutrients and plant growth promotion. Vermicompost increases the absorption and transition of nutrients from soil to roots and improves plant growth (Simsek-Ersahin, 2011. Zn and Fe application is highly important; foliar application causes faster and higher absorption rate and cures deficiencies symptoms (Ghaffari et al., 2010. Thiobacillus is a chemolithotroph bacterium, receiving energy from sulfur oxidation. This bacterium acidifies microcites in the rhizosphere, increasing the availability of nutrients to plant roots (Kaya et al., 2009. Regarding the benefits of integrated nutrient management, this experiment was conducted with the aim of testing the effects of Fe and Zn foliar spraying, Thiobacillu sthiooxidans inoculation and vermicompost application on growth, yield and bio fortification of popcorn maize. Materials and methods This experiment was conducted in 2012 at the research field of Islamic Azad University, Tabriz branch, Iran. The experiment was conducted in factorial in the form of a randomized complete block design with three replications and four factors: vermicompost application in soil (0 and 2 t.ha-1, applied in strip form below the seeds before cultivation, inoculation with Thiobacillus thiooxidans, with a population of 108cfu.g-1. Sulfur was inoculated with T. thiooxidans prior to application. Fe chelate foliar application (without spraying and two times spraying of 0.002 concentration of 13% Fe chelate and Zn chelate foliar application (without spraying and two times spraying of 0.002 concentration of 15% Zn chelate. Maize seeds (Zea mays L. var

Biodesulfurization of dibenzothiophene in Escherichia coli is enhanced by expression of a Vibrio harveyi oxidoreductase gene

Energy Technology Data Exchange (ETDEWEB)

Reichmuth, D.S.; Hittle, J.L.; Blanch, H.W.; Keasling, J.D.

2000-01-05

One possible alternative to current fuel hydrodesulfurization methods is the use of microorganisms to remove sulfur compounds. Biodesulfurization requires much milder processing conditions, gives higher specificity, and does not require molecular hydrogen. In the present work the authors have produced two compatible plasmids: pDSR3, which allows Escherichia coli to convert dibenzothiophene (DBT) to hydroxybiphenyl (HBP), and pDSR2, which produces a Vibrio harveyi flavin oxidoreductase. The authors show that the flavin oxidoreductase enhances the rate of DBT removal when co-expressed in vivo with the desulfurization enzymes. The plasmids pDSR2 and pDSR3 were co-expressed in growing cultures. The expression of oxidoreductase caused an increase in the rate of DBT removal but a decrease in the rate of HBP production. The maximum rate of DBT removal was 8 mg/h {center{underscore}dot} g dry cell weight. Experiments were also conducted using resting cells with the addition of various carbon sources. It was found that the addition of glucose or glycerol to cultures with oxidoreductase expression produced the highest DBT removal rate. The culture with acetate and no oxidoreductase expression had the highest level of HBP production. For all carbon sources, the DBT removal rate was faster and the HBP generation rate slower with the expression of the oxidoreductase. Analysis of desulfurization intermediates indicates that the last enzyme in the pathway may be limiting.

Improvement of Biodesulfurization Rate of Alginate Immobilized Rhodococcus erythropolis R1

Science.gov (United States)

Derikvand, Peyman; Etemadifar, Zahra

2014-01-01

Background: Sulfur oxides released from the burning of oil causes severe environmental pollution. The sulfur can be removed via the 4S pathway in biodesulfurization (BDS). Immobilization approaches have been developed to prevent cell contamination of oil during the BDS process. Objectives: The encapsulation of Rhodococcus erythropolis R1 in calcium alginate beads was studied in order to enhance conversion of dibenzothiophene (DBT) to 2-hydroxy biphenyl (2-HBP) as the final product. Also the effect of different factors on the BDS process was investigated. Materials and Methods: Calcium alginate capsules were prepared using peristaltic pumps with different needle sizes to control the beads sizes. Scanning electron microscopy and flow cytometry methods were used to study the distribution and viability of encapsulated cells, respectively. Two non-ionic surfactants and also nano Ƴ-Al2O3were used with the ratio of 0.5% (v/v) and 1:5 (v/v) respectively to investigate their BDS efficiency. In addition, the effect of different bead sizes and different concentrations of sodium alginate in BDS activity was studied. Results: The 2% (w/v) sodium alginate beads with 1.5mm size were found to be the optimum for beads stability and efficient 2-HBP production. The viability of encapsulated cells decreased by 12% after 20 h of desulfurization, compared to free cells. Adding the non-ionic surfactants markedly enhanced the rate of BDS, because of increasing mass transfer of DBT to the gel matrix. In addition, Span 80 was more effective than Tween 80. The nanoƳ-Al2O3 particles could increase BDS rate by up to two-folds greater than that of the control beads. Conclusions: The nano Ƴ-Al2O3 can improve the immobilized biocatalyst for excellent efficiency of DBT desulfurization. Also the BDS activity can be enhanced by setting the other explained factors at optimum levels. PMID:25147685

Effect of Thiobacillus thioparus 1904 and sulphur addition on odour emission during aerobic composting.

Science.gov (United States)

Gu, Wenjie; Sun, Wen; Lu, Yusheng; Li, Xia; Xu, Peizhi; Xie, Kaizhi; Sun, Lili; Wu, Hangtao

2018-02-01

The effects of sulphur and Thiobacillus thioparus 1904 on odour emissions during composting were studied. Results indicated that the sulphur addition reduced the pH and decreased cumulative emission of ammonia and the nitrogen loss by 47.80% and 44.23%, respectively, but the amount of volatile sulphur compounds (VSCs) and the sulphur loss increased. The addition of T. thioparus 1904 effectively reduced the cumulative emissions of H 2 S, methyl sulphide, methanethiol, dimethyl disulphide and the sulphur loss by 33.24%, 81.24%, 32.70%, 54.22% and 54.24%, respectively. T. thioparus 1904 also limited the nitrogen loss. The combined application of sulphur and T. thioparus 1904 resulted in the greatest amount of nitrogen retention. The accumulation of ammonia emissions was reduced by 63.33%, and the nitrogen loss was reduced by 71.93%. The combined treatment did not increase the emission of VSCs. The application of sulphur and T. thioparus 1904 may help to control the odour of compost. Copyright © 2017. Published by Elsevier Ltd.

Biodesulfurization of dibenzothiophene in Escherichia coli is enhanced by expression of a Vibrio harveyi oxidoreductase gene.

Science.gov (United States)

Reichmuth, D S; Hittle, J L; Blanch, H W; Keasling, J D

2000-01-05

One possible alternative to current fuel hydrodesulfurization methods is the use of microorganisms to remove sulfur compounds. Biodesulfurization requires much milder processing conditions, gives higher specificity, and does not require molecular hydrogen. In the present work we have produced two compatible plasmids: pDSR3, which allows Escherichia coli to convert dibenzothiophene (DBT) to hydroxybiphenyl (HBP), and pDSR2, which produces a Vibrio harveyi flavin oxidoreductase. We show that the flavin oxidoreductase enhances the rate of DBT removal when co-expressed in vivo with the desulfurization enzymes. The plasmids pDSR2 and pDSR3 were co-expressed in growing cultures. The expression of oxidoreductase caused an increase in the rate of DBT removal but a decrease in the rate of HBP production. The maximum rate of DBT removal was 8 mg/h. g dry cell weight. Experiments were also conducted using resting cells with the addition of various carbon sources. It was found that the addition of glucose or glycerol to cultures with oxidoreductase expression produced the highest DBT removal rate (51 mg/h. g dry cell weight). The culture with acetate and no oxidoreductase expression had the highest level of HBP production. For all carbon sources, the DBT removal rate was faster and the HBP generation rate slower with the expression of the oxidoreductase. Analysis of desulfurization intermediates indicates that the last enzyme in the pathway may be limiting. Copyright 2000 John Wiley & Sons, Inc.

A kinetic study of the depyritization of oil shale HCl-kerogen concentrate by Thiobacillus ferrooxidans at different temperatures

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OLGA CVETKOVIC

2003-05-01

Full Text Available The results of kinetic studies of bacterial depyritization of HCl-kerogen concentrate of Aleksinac (Serbia oil shale by the chemolithoautotrophic thionic bacteria Thiobacillus ferrooxidans under discontinuous laboratory conditions at various temperatures (0, 20, 28 and 37°C at a pH of ca. 1.5 are presented in this paper. Low pH prevents the occurrence of the precipitation of iron(III-ion hydrolysis products on the substrate particles and thereby reduces the process efficiency. Bacterial depyritization is developed as per kinetics of the first order. The activation energy which points to a successive mechanism of pyrite biooxidation, was computed from the Arrhenius plot. The biochemical kinetics indicators point to a high affinity of the bacteria toward pyrite but small values of Vmax, which are probably the result of decelerated metabolic processes due to the low pH value of the environment resp. the large difference of the pH between the external medium and the cell interior.

Biodesulfurization techniques: Application of selected microorganisms for organic sulfur removal from coals. Final report

Energy Technology Data Exchange (ETDEWEB)

Elmore, B.B.

1993-08-01

As an alternative to post-combustion desulfurization of coal and pre-combustion desulfurization using physicochemical techniques, the microbial desulfurization of coal may be accomplished through the use of microbial cultures that, in an application of various microbial species, may remove both the pyritic and organic fractions of sulfur found in coal. Organisms have been isolated that readily depyritize coal but often at prohibitively low rates of desulfurization. Microbes have also been isolated that may potentially remove the organic-sulfur fraction present in coal (showing promise when acting on organic sulfur model compounds such as dibenzothiophene). The isolation and study of microorganisms demonstrating a potential for removing organic sulfur from coal has been undertaken in this project. Additionally, the organisms and mechanisms by which coal is microbially depyritized has been investigated. Three cultures were isolated that grew on dibenzothiophene (DBT), a model organic-sulfur compound, as the sole sulfur source. These cultures (UMX3, UMX9, and IGTS8) also grew on coal samples as the sole sulfur source. Numerous techniques for pretreating and ``cotreating`` coal for depyritization were also evaluated for the ability to improve the rate or extent of microbial depyritization. These include prewashing the coal with various solvents and adding surfactants to the culture broth. Using a bituminous coal containing 0.61% (w/w) pyrite washed with organic solvents at low slurry concentrations (2% w/v), the extent of depyritization was increased approximately 25% in two weeks as compared to controls. At slurry concentrations of 20% w/v, a tetrachloroethylene treatment of the coal followed by depyritization with Thiobacillus ferrooxidans increased both the rate and extent of depyritization by approximately 10%.

Aplicação de técnicas eletroquímicas no estudo da dissolução oxidativa da covelita (CuS por Thiobacillus ferrooxidans Electrochemical techniques applied to study the oxidative dissolution of the covellite: CuS by Thiobacillus ferrooxidans

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Christiane Medina Teixeira

2002-02-01

Full Text Available Among the copper sulphides, chalcopyrite (CuFeS2, covellite (CuS and chalcocite (Cu2S are the most important source of minerals for copper mining industry. The acknowledge of behaviour of these sulphides related with bacterial leaching process are essential for optimization procedures. Despite of its importance, covellite has not deserved much interest of researchers regarding this matter. In this work it was studied the oxidation of covellite by the chemolithotrophic bacterium Thiobacillus ferrooxidans by using electrochemical techniques, such as open circuit potentials with the time and cyclic voltammetry. The experiments were carried out in acid medium (pH 1.8, containing or not Fe2+ as additional energy source, and in different periods of incubation; chemical controls were run in parallel. The results showed that a sulphur layer is formed spontaneously due the acid attack, covering the sulphide in the initial phase of incubation, blocking the sulphide oxidation. However, the bacterium was capable to oxidize this sulphur layer. In the presence of Fe2+ as supplemental energy source, the corrosion process was facilitated, because ocurred an indirect oxidation of covellite by Fe3+, which was produced by T. ferrooxidans oxidation of the Fe2+ added in the medium.

Hydrogen sulfide oxidation in novel Horizontal-Flow Biofilm Reactors dominated by an Acidithiobacillus and a Thiobacillus species.

Science.gov (United States)

Gerrity, S; Kennelly, C; Clifford, E; Collins, G

2016-09-01

Hydrogen Sulfide (H2S) is an odourous, highly toxic gas commonly encountered in various commercial and municipal sectors. Three novel, laboratory-scale, Horizontal-Flow Biofilm Reactors (HFBRs) were tested for the removal of H2S gas from air streams over a 178-day trial at 10°C. Removal rates of up to 15.1 g [H2S] m(-3) h(-1) were achieved, demonstrating the HFBRs as a feasible technology for the treatment of H2S-contaminated airstreams at low temperatures. Bio-oxidation of H2S in the reactors led to the production of H(+) and sulfate (SO(2-)4) ions, resulting in the acidification of the liquid phase. Reduced removal efficiency was observed at loading rates of 15.1 g [H2S] m(-3) h(-1). NaHCO3 addition to the liquid nutrient feed (synthetic wastewater (SWW)) resulted in improved H2S removal. Bacterial diversity, which was investigated by sequencing and fingerprinting 16S rRNA genes, was low, likely due to the harsh conditions prevailing in the systems. The HFBRs were dominated by two species from the genus Acidithiobacillus and Thiobacillus. Nonetheless, there were significant differences in microbial community structure between distinct HFBR zones due to the influence of alkalinity, pH and SO4 concentrations. Despite the low temperature, this study indicates HFBRs have an excellent potential to biologically treat H2S-contaminated airstreams.

Charge and softness of the outer part of the cell wall of Thiobacillus ferrooxidans in the low ionic strength medium

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Škvarla Jiří

2002-03-01

Full Text Available The surface charge and surface potential are parameters influencing the microbial adhesion phenomenon through the electrostatic interaction between bacteria and substrates. The Smoluchowski equation, originally developed for estimating the above parameters from the experimentally accessible electrophoretic mobility of rigid colloid particles, is however inapplicable to the elastic bacterial cells. The problem is that the outer cell wall of bacteria is a layer with a complex polyelectrolyte structure. In this article, the OhshimaLs model of the gsofth particle is applied to describe the surface electrostatics of Thiobacillus ferrooxidans cells by measuring their electrophoretic mobility in distilled water as a function of a (low ionic strength and pH. In this model, the rigid core is considered to be covered with a charged ion-penetrable layer of polyelectrolytes. Two model parameters have been determined by the curve fitting at pH from 3.2 to 5.8, namely the number density of the dissociated groups N and the softness parameter 1/ƒÉ of the polyelectrolyte layer of the bacterium. A disagreement of the best fit parameters (evaluated by the correlation coefficient with the analogous parameters determined for other colloids (including bacterial cells in aqueous solutions of a high ionic strength is discussed.

Genome-enabled studies of anaerobic, nitrate-dependent iron oxidation in the chemolithoautotrophic bacterium Thiobacillus denitrificans

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Harry R Beller

2013-08-01

Full Text Available Thiobacillus denitrificans is a chemolithoautotrophic bacterium capable of anaerobic, nitrate-dependent U(IV and Fe(II oxidation, both of which can strongly influence the long-term efficacy of in situ reductive immobilization of uranium in contaminated aquifers. We previously identified two c-type cytochromes involved in nitrate-dependent U(IV oxidation in T. denitrificans and hypothesized that c-type cytochromes would also catalyze Fe(II oxidation, as they have been found to play this role in anaerobic phototrophic Fe(II-oxidizing bacteria. Here we report on efforts to identify genes associated with nitrate-dependent Fe(II oxidation, namely (a whole-genome transcriptional studies [using FeCO3, Fe2+, and U(IV oxides as electron donors under denitrifying conditions], (b Fe(II oxidation assays performed with knockout mutants targeting primarily highly expressed or upregulated c-type cytochromes, and (c random transposon-mutagenesis studies with screening for Fe(II oxidation. Assays of mutants for 26 target genes, most of which were c-type cytochromes, indicated that none of the mutants tested were significantly defective in nitrate-dependent Fe(II oxidation. The non-defective mutants included the c1-cytochrome subunit of the cytochrome bc1 complex (complex III, which has relevance to a previously proposed role for this complex in nitrate-dependent Fe(II oxidation and to current concepts of reverse electron transfer. A transposon mutant with a disrupted gene associated with NADH:ubiquinone oxidoreductase (complex I was ~35% defective relative to the wild-type strain; this strain was similarly defective in nitrate reduction with thiosulfate as the electron donor. Overall, our results indicate that nitrate-dependent Fe(II oxidation in T. denitrificans is not catalyzed by the same c-type cytochromes involved in U(IV oxidation, nor have other c-type cytochromes yet been implicated in the process.

The Biocatalytic Desulfurization Project

Energy Technology Data Exchange (ETDEWEB)

David Nunn; James Boltz; Philip M. DiGrazia; Larry Nace

2006-03-03

The material in this report summarizes the Diversa technical effort in development of a biocatalyst for the biodesulfurization of Petro Star diesel as well as an economic report of standalone and combined desulfurization options, prepared by Pelorus and Anvil, to support and inform the development of a commercially viable process. We will discuss goals of the projected as originally stated and their modification as guided by parallel efforts to evaluate commercialization economics and process parameters. We describe efforts to identify novel genes and hosts for the generation of an optimal biocatalyst, analysis of diesel fuels (untreated, chemically oxidized and hydrotreated) for organosulfur compound composition and directed evolution of enzymes central to the biodesulfurization pathway to optimize properties important for their use in a biocatalyst. Finally we will summarize the challenges and issues that are central to successful development of a viable biodesulfurization process.

Role of Thiobacillus thioparus in the biodegradation of carbon disulfide in a biofilter packed with a recycled organic pelletized material.

Science.gov (United States)

Prenafeta-Boldú, Francesc X; Rojo, Naiara; Gallastegui, Gorka; Guivernau, Miriam; Viñas, Marc; Elías, Ana

2014-07-01

This study reports the biodegradation of carbon disulfide (CS2) in air biofilters packed with a pelletized mixture of composted manure and sawdust. Experiments were carried out in two lab-scale (1.2 L) biofiltration units. Biofilter B was seeded with activated sludge enriched previously on CS2-degrading biomass under batch conditions, while biofilter A was left as a negative inoculation control. This inoculum was characterized by an acidic pH and sulfate accumulation, and contained Achromobacter xylosoxidans as the main putative CS2 biodegrading bacterium. Biofilter operation start-up was unsuccessfully attempted under xerophilic conditions and significant CS2 elimination was only achieved in biofilter A upon the implementation of an intermittent irrigation regime. Sustained removal efficiencies of 90-100 % at an inlet load of up to 12 g CS2 m(-3) h(-1) were reached. The CS2 removal in this biofilter was linked to the presence of the chemolithoautotrophic bacterium Thiobacillus thioparus, known among the relatively small number of species with a reported capacity of growing on CS2 as the sole energy source. DGGE molecular profiles confirmed that this microbe had become dominant in biofilter A while it was not detected in samples from biofilter B. Conventional biofilters packed with inexpensive organic materials are suited for the treatment of low-strength CS2 polluted gases (IL biofiltration of recalcitrant compounds has been highlighted.

Distribution, ecology and inhibition of Thiobacillus ferrooxidans in relation to acid drainage from Witwatersrand gold mine dumps

International Nuclear Information System (INIS)

Whillier, P.A.

1987-03-01

The distribution and ecology of Thiobacillus ferrooxidans in gold mine dumps and possible means for its inhibition were investigated. A literature survey of the micro-ecology of mine waste dumps in various parts of the world was undertaken. A linear alkylbenzene sulphonate (LAS), NANSA 80/S, and a cetyl pyridinium chloride, Ceepryn, were tested as possible inhibitors for mine dump application. The LAS was rejected because it is poorly soluble in water and required higher concentrations than SLS for the inhibition of T.ferrooxidans. Ceepryn was an efficient inhibitor, but its efficiency was dramatically impeded in the presence of mine dump sand making it unsuitable for application on dumps. The SLS and LAS were tested against a mixed population of T.ferrooxidans from gold mine dumps and these bacteria were shown to be marginally more resistant to the inhibitors than the pure T.ferrooxidans culture. Sampling from mine dumps on the Witwatersrand suggested that the major T.ferrooxidans populations occurred in the moist sand of the drainage areas at the base of dumps, with few viable iron-oxidising bacteria located on the surfaces or in the centre of dumps. Sites of low moisture in dumps contained few or no viable bacteria. In the laboratory the bacterial viability decreased rapidly with loss of moisture from the sand. Moisture was shown to be important to bacterial activity and should be considered with respect to acid drainage control. Experimental sand columns showed that iron was leached with water from mine dump sand in the absence and presence of bacteria. In this study substrates, moisture, oxygen and carbon dioxide availability, ph, temperature, microorganisms and metal pollutants of uranium waste dumps are also covered

Oxidation of inorganic compounds of sulphur by various sulphur bacteria

Energy Technology Data Exchange (ETDEWEB)

Parker, C D; Prisk, J

1953-01-01

Cultures of thiobacillus thiooxidans, Th. thioparus, Th. novellus, Thiobacillus b strains t and kand Th. concretivorus, Thiobacillus x and the m strains, organisms isolated from concrete were examined to elucidate the mode of oxidation and to establish the identity of the organisms recently isolated from corroded concrete. Thiosulphate was oxidized by all these bacteria. Th. thiooxidans, Th. concretivorus and Thiobacillus x first converted it to tetrathionate and sulphate and then oxidized the tetrathionate to sulphate and free sulphuric acid. Thiobaciullus x differed from the other two in that, owing to a lesser acid tolerance, some tetrathionate was found in the final products of oxidation. Th. Thioparus converted thiosulphate to sulphate and sulphur, followed by partial oxidation of the sulphur to sulphuric acid. Th. novellus produced sulphate and sulphuric acid. Thiobacillus b, the t and k strains and the m strains formed sulphate and tetrathionate with temporary increase in pH value; only Thiobacillus x oxidized tetrationate, yielding sulphate and sulphuric acid. Elementary sulphur was oxidized by Th. thiooxidans, th. Concretivorus, thiobacillus x and Th. thioparus; the rates of oxidation decreased in that order, and the only product was sulphuric acid. Hydrogen sulphide was oxidized only at low concentrations and only by th. Concretivorus and Thiobacillus x; sulphuric acid was the end-product, and elementary sulphur may have been an intermediate. Thiobacillus x differed from Th. thiooxidans in pH range for growth and from Th. thioparus in its method of oxidation of thiosulphate, tetrathionate and H/sub 2/S. The m strains were similar to thiobacillus b and the t and k strains of trautwein.

Synonyms for some species of Mexican anoles (Squamata: Dactyloidae).

Science.gov (United States)

De Oca, Adrián Nieto Montes; Poe, Steven; Scarpetta, Simon; Gray, Levi; Lieb, Carl S

2013-01-01

We studied type material and freshly collected topotypical specimens to assess the taxonomic status of five names associated with species of Mexican Anolis. We find A. schmidti to be a junior synonym of A. nebulosus, A. breedlovei to be a junior synonym of A. cuprinus, A. polyrhachis to be a junior synonym of A. rubiginosus, A. simmonsi to be a junior synonym of A. nebuloides, and A. adleri to be a junior synonym of A. liogaster.

Microbial desulfurization of coal

International Nuclear Information System (INIS)

Bos, P.; Boogerd, F.C.; Kuenen, J.G.

1992-01-01

In recent years, studies have been initiated to explore the possibilities of the use of biological systems in coal technology. This chapter discusses the principles behind the bioprocessing of coal, the advantages and disadvantages, and the economic feasibility of the process. For large-scale, coal-using, energy-producing plants, stack gas cleaning should be the treatment of choice. Biodesulfurization is preferable with industrial, small-scale, energy-producing plants. Treatment of the stack gases of these plants is not advisable because of high investment costs. Finally, it should be realized that biodesulfurization produces a waste stream that needs further treatment. 91 refs

Biodegradation of Mustard

Science.gov (United States)

1994-07-01

different areas of Kuwait. The isolates were identified as Asoeraillus terreus, h. IlabirM, Mucor alobosus, usarium sp . and Penicillium citrinum (94...Thiobacillus delicatus nov. sp . J. Ferment . Technol. 54:181-191 (1976). (39) Harrison, AP. The acidophilic thiobacilli and other acidophilic bacteria...methyl sulfide is oxidized to sulfate by Hnhomicrobium S sp ., Hynhomicrobu EG (21-23), Thiobacillus thioDarus TK-m and Thiobacillus MS1 (24,25), but only

Bioextraction of copper and zinc from fly ash from coal combustion

Energy Technology Data Exchange (ETDEWEB)

Wilczok, T; Cwalina, B; Chrostowska, D

1986-02-01

Results are evaluated of investigations carried out by the Institute of Chemistry and Physics of the Silesia Medical Academy in Sosnowiec into feasibility of bacterial leaching for utilization of fly ash from combustion of black coal. Fly ash separated by electrostatic precipitators in the Dolna Odra power plant fired with black coal was used. Copper content in the fly ash on the average was 0.012%, that of zinc was 0.025%. When Thiobacillus ferroxidans, Thiobacillus thiooxidans and bacteria separated from fly ash were used leaching efficiency after 21 days ranged from 69 to 87% in the case of copper and from 48 to 72% in the case of zinc. Origin of bacteria separated from fly ash was unclear. Autochthonous bacteria in the fly ash being leached increased efficiency of bacterial leaching. Effects of autochthonous bacteria were similar to those of the bacterial culture of Thiobacillus ferroxidans and Thiobacillus thiooxidans. Investigation results were shown in a table and 2 diagrams. 19 references.

FY 1994 report on the cooperative research on the biological use mine wastewater treatment technology; 1994 nendo bio riyo ni yoru kohaisui shori gijutsu ni kansuru kenkyu kyoryoku hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

In this project, a pilot plant for mine wastewater treatment facilities using Thiobacillus ferrooxidans was installed at the Wushan mine in China to study the operation using the bacteria habitable in this mine. The project aims at establishing the mine wastewater treatment technology using the method of Thiobacillus ferrooxidans in China. The field survey and study in Japan were carried out. In the field survey, the technical guidance was given for incubation method, neutralization experiment method and analysis method of Thiobacillus ferrooxidans. In the study in Japan, one kind of bacteria to be used was selected in the 'selection test for the optimum kind of bacteria,' and a study was made which was titled 'Study of mine wastewater treatment using the method of Thiobacillus ferrooxidans which is suitable for the mine site.' In 'Study of the optimum removal of heavy metal in mine wastewater,' a table test of sulfide precipitation method was conducted on copper removal/recovery to make formation conditions of copper sulfide clear. The conditions obtained were reflected in 'Study of mine wastewater treatment by the method of Thiobacillus ferrooxidans which is suitable for the mine site,' and various conditions for bacteria oxidation process were studied. The paper surveyed characteristics of heavy metal and temperature of Chinese strains. Further, the basic data were acquired which contribute to the production of inorganic flocculants. (NEDO)

Gas, oil, and environmental biotechnology IV

Energy Technology Data Exchange (ETDEWEB)

Akin, C; Markuszewski, R; Smith, J [eds.; Institute of Gas Technology, Chicago, IL (United States)

1992-01-01

Contains 32 papers presented at the 4th international IGT symposium on gas, oil and environmental biotechnology. Topics covered were: hydrocarbon bioremediation; groundwater, soil and explosives bioremediation; gas and oil reservoir souring; and biodesulfurization. 2 papers have been abstracted separately.

Microbial oxidation and reduction of inorganic sulphur compounds in relation to the development and control of microorganisms active in leaching operations. Part of a coordinated programme on bacterial leaching of uranium ores

International Nuclear Information System (INIS)

Tuovinen, O.H.

1977-01-01

The project considers the use of Thiobacillus ferroxidans type bacteria for the leaching of metals from ores. The various ways by which Thiobacillus ferroxidans utilizes inorganic sulfur compounds for oxidation, energy, growth and synthesis of cellular material were studied. The report briefly describes the scope and background of the project, and a list of publications describing experimental methods and research materials used is given. Unpublished work commenced during the Research Contract includes three major projects: (1) Transition of Thiobacillus ferroxidans from heterotrophic growth on fucose to autotropic growth on ferrous-iron; (2) development of a method to determine the ATP-content of bacteria attached to ore particles; (3) microbiological and chemical interactions of inorganic sulfur compounds. These three projects are summarized briefly

Anaerobic biodesulfurization of thiophenes

NARCIS (Netherlands)

Marcelis, C.

2002-01-01

Distillates from crude oil such as diesel and fuel oil may contain significant amounts of dibenzothiophenes and their alkylated derivatives, containing organically bound sulfur. Combustion of those fossil fuels leads to the release of polluting sulfur dioxide into the atmosphere, where it causes

African Journal of Biotechnology - Vol 5, No 4 (2006)

African Journals Online (AJOL)

Biodesulfurization of dibenzothiophene and its alkylated derivatives through the sulfur-specific pathway by the bacterium RIPI-S81 · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Ladan Rashidi, Ghasemali Mohebali, Jafar Towfighi Darian, Behnam Rasekh, 351- ...

Biochemical solubilization of toxic salts from residual geothermal brines and waste waters

Science.gov (United States)

Premuzic, Eugene T.; Lin, Mow S.

1994-11-22

A method of solubilizing metal salts such as metal sulfides in a geothermal sludge using mutant Thiobacilli selected for their ability to metabolize metal salts at high temperature is disclosed, The method includes the introduction of mutated Thiobacillus ferrooxidans and Thiobacillus thiooxidans to a geothermal sludge or brine. The microorganisms catalyze the solubilization of metal salts, For instance, in the case of metal sulfides, the microorganisms catalyze the solubilization to form soluble metal sulfates.

[Application of immunologic methods to the analysis of bio-leaching bacteria].

Science.gov (United States)

Coto, O; Fernández, A I; León, T; Rodríguez, D

1994-09-01

Pure cultures of Thiobacillus ferrooxidans and mixed cultures of Thiobacillus ferrooxidans and Leptospirillum ferrooxidans isolated from the Matahambre mine (Cuba) were used to fit immunodiffusion and immunoelectron microscopy to the study of iron oxidizing bacteria. The possibilities, advantages and limits of those techniques have been studied from both the identification and the serological characterization points of view. Finally, the efficiency of these methods was tested by applying them to the identification of microorganisms from acidic waters from the mine.

Influencia de la concentración de hierro y pH iniciales en un proceso de biodesulfurización de carbón – ensayos a nivel de laboratorio

Directory of Open Access Journals (Sweden)

Gerardo Andrés Caicedo Pineda

2011-07-01

Full Text Available Título en ingles: Particle size, iron concentration and pH influence in biodesulfurization process of coal – laboratory tests   Resumen   A un carbón proveniente del municipio de Puerto Libertador, Córdoba-Colombia (2.34% de azufre total, con 1.34% pirítico, 0.90% orgánico y 0.10% de sulfatos, se le aplicó un cultivo mixto de Acidithiobacillus ferrooxidans y Acidithiobacillus thiooxidans, con el fin de evaluar procesos de biodesulfurización en suspensión, a partir de variables que influyen en el proceso: concentración inicial de hierro y pH de la solución lixiviante, bajo dos configuraciones de tamaño de partícula: pasante malla 8 (-malla 8 y pasante malla 60 (-malla 60, acorde con la serie Tyler de tamices. Los procesos de biodesulfurización se evaluaron cada dos días, mediante mediciones de la concentración de hierro, pH, potencial de óxido-reducción y crecimiento celular, en la solución. A partir de los ensayos realizados, se alcanzaron oxidaciones de azufre pirítico por encima del 50%, después de 12 días de proceso. Se pudo constatar que tanto el tipo de carbón tratado, como de las condiciones evaluadas, inciden en el grado de lixiviación alcanzado. La mejor eficiencia del proceso se observó al utilizar concentraciones de hierro iniciales menores a 1200 ppm y un pH inicial entre 1.5 y 1.3.   Palabras clave: Acidithiobacillus, biodesulfurización, carbón, hierro removido, pirita.   Abstract   Biodesulfurization process for Colombian coal (2.34% total sulfur: 1.34% as pyritic, 0.90% as organic and 0.10% from sulfates from municipality of Puerto Libertador (Córdoba, Colombia was carried out. A mixed culture of A. ferrooxidans and A. thiooxidans was used. The study was mainly focused on the influence of pH, and iron concentration in coal leaching process. Two mineral particle sizes were evaluated: less 8 mesh (-malla 8 and less 60 mesh (-malla 60, Tyler series. Biodesulfurization processes were determined by

Bacterial leaching of uranium ores - a review

International Nuclear Information System (INIS)

Lowson, R.T.

1975-11-01

The bacterial leaching of uranium ores involves the bacterially catalysed oxidation of associated pyrite to sulphuric acid and Fe 3+ by autotrophic bacteria and the leaching of the uranium by the resulting acidic, oxidising solution. Industrial application has been limited to Thiobacillus thiooxidans and Thiobacillus ferrooxidans at pH 2 to 3, and examples of these are described. The bacterial catalysis can be improved with nutrients or prevented with poisons. The kinetics of leaching are controlled by the bed depth, particle size, percolation rate, mineralogy and temperature. Current work is aimed at quantitatively defining the parameters controlling the kinetics and extending the method to alkaline conditions with other autotrophic bacteria. (author)

Desulfurization of fuels with ionic liquids by extraction and oxidative extraction processes

OpenAIRE

Rodríguez Cabo, Borja

2014-01-01

The excessive emission of pollutants to the atmosphere has been a problem during the last few decades due to, among other reasons, the massive use of transports. In order to avoid this problem, many methods are being investigated as an alternative to the classical hydrodesulfurization technique, such as adsorption, biodesulfurization, extraction and oxidation. The extractive desulfurization is one of the most promising alternatives. Moreover, its enhancement with selective oxidation of sulfur...

Using microbiological leaching method to remove heavy metals from sludge

Directory of Open Access Journals (Sweden)

Zhuyu Gu

2017-01-01

Full Text Available Microbial leaching is one of the most effective methods to remove heavy metals from sludge. In the conducted researches, the sludge samples were processed with Thiobacillus ferrooxidans and Thiobacillus thiooxidans obtained via cultivation, extraction and purification processes. Heavy metals such as Pb, Cd, Cu and Ni were leached from sludge by Thiobacillus ferrooxidans and Thiobacillus thiooxidans within different substrate concentration and pH value conditions. It is defined that from the point of view of economy and efficiency the optimal concentration of FeSO4.7H2O and sulfur for bio-leaching process was 0.2 g. The leaching rates of heavy metals such as Pb, Cd, Cu and Ni of the same concentration were 74.72%, 81.54%, 70.46% and 77.35% respectively. However, no significant differences depending on the pH value among the leaching rates were defined, even for the pH value of 1.5. Along with the removal of heavy metals from sludge, the organic matter, N, P, K were also leached to some extent. The losing rate of phosphorus was the highest and reached 38.44%. However, the content of organic matter, N, P, K in the processed sludge were higher in comparison with level I of the National Soil Quality Standards of China. Ecological risk of heavy metals in sludge before and after leaching was assessed by Index of Geo-accumulation (Igeo and comprehensive potential risk (RI. The results of research defined that the content of heavy metals in sludge meets the level of low ecological risk after leaching and their contents is lower in comparison with the National Agricultural Sludge Standard of China. Sludge leached by biological methods is possible to use for treatment for increasing soil fertility.

Elective culture of bacteria used in bioleaching on pyrrhotite

Institute of Scientific and Technical Information of China (English)

邱冠周; 覃文庆; 蓝卓越; 黎维中

2003-01-01

Elective culture of bacteria on pyrrhotite was researched, and the selected bacteria were tested on bi-oleaching of marmatite and zinc sulfide ore. The results show that the microorganism cultured on pyrrhotite with va-rious S/Fe ratios is a mixed culture of thiobacillus ferrooxidans and thiobacillus thiooxidans, of which the integral ac-tivity and the oxidation capability of Fe2+ and S are enhanced. With the high Fe and low S content of pyrrhotite, the oxida-tion capacity of ferrous ion is improved; on the contrary, the oxidation capacity of sulfur is advanced. The bioleaching ca-pacity of bacteria cultured on marmatite is better than that of the bacteria cultivated by conventional methods.

Increasing the production of desulfurizing biocatalysts by means of fed - batch culture

International Nuclear Information System (INIS)

Berdugo, C I; Mena, J A; Acero, J R; Mogollon, L

2001-01-01

Over the past years, environmental regulations have driven a lot of effort for the development of new technologies for the upgrading of fossil fuels. Biotechnology offers an alternative way to process fossil fuels by means of a biodesulfurization technology where the production of the biocatalyst is one of the key topics. Traditionally, the production is carried out in batch culture where the maximum cellular concentration is restricted by inherent limitations of the culture type and the microorganism growth rate. This work addresses the production of two desulfurizing microorganisms: Rhodococcus erythropolis IGTS8 and gordona rubropertinctus ICP172 using fed-batch culture. Fed-batch cultures were conducted in a 12 L fermentor using ICP 4 medium containing glucose and DMSO as carbon and sulfur sources. As a result, cell concentration was increased 1.5 and 3 times with fed-batch cultures using constant and exponential flow respectively, achieving a maximum cell concentration of 7.3 g DCW/L of biocatalyst igts8 and 12.85 gGDCW/L of the new biocatalyst ICP172. Both biocatalysts presented biodesulfurization activity in a spiked matrix DBT/HXD and in diesel matrix with the detection of 2-HBP which is the end-product of DBT degradation pathway

Sodium lauryl sulfate - a biocide for controlling acidity development in bulk commercially formed solid elemental sulfur

Energy Technology Data Exchange (ETDEWEB)

Hyne, J. B. [Calgary Univ., AB (Canada). Dept. of Biological Sciences

1996-04-01

Acidification of bulk elemental sulfur caused by Thiobacillus species which consume elemental sulfur by converting it into oxidized sulfur forms, was studied. Contributory factors, such as length of time in transit or in storage, warm temperatures, the presence of air and moisture, particle size and form of sulfur, and the presence of sources of carbon, nitrogen and phosphorus nutrients, were reviewed. Laboratory experiments with adding sodium lauryl sulfate (SLS), a known biocide, to sulfur inoculated with Thiobacillus, proved to be an efficient method for controlling acidity development. At the concentration required for effectiveness SLS did not interfere with purity specifications, had negligible effect on moisture, and appeared to be compatible with current dust suppression application practices. 2 tabs., 3 figs.

Exploration on trickle leaching of uranium ore by refreshed liquor of bacterial oxidation

International Nuclear Information System (INIS)

Chen Shian; Huang Xiangfu; Fan Baotuan

1995-01-01

The paper describes the adaptation of the domesticated thiobacillus ferroxidans to the trickle leaching conditions of uranium ore. When the bacterial leaching liquor through multiple cycles of oxidation and regeneration was used to return to the trickle leaching, the following results were obtained: the extraction rate was more than 95%, the acid consumption was saved by 30%, and the consumed 2.0% pyrolusite (MnO 2 40%) was eliminated. The following problems are discussed: the basic principle, process and some factors influencing the process of the trickle leaching of uranium ore using regenerated liquor of bacterial oxidation, counter-current trickle leaching mode, oxidation and regeneration techniques of bacterial leaching liquor and other technological problems on the process of uranium extraction by thiobacillus ferroxidans

Microbial leaching of low grade copper ores

International Nuclear Information System (INIS)

Rauf, A.; Ashfaq, M.

1991-01-01

Biotechnology is regarded as one of the most promising and revolutionary solution to various problems which are generally faced in the extraction of metals from their ores such as high energy, capital costs and environmental pollution. The paper deals with the study of low grade copper ores for their beneficiation and extraction of copper. The ores used were chalcopyrite and oxidized copper ores. Microorganisms play a vital role in the solubilization of valuable contents from ores such as copper and other metals. Studies have been conducted on the indigenous copper ores by using thiobacillus ferro oxidans and thiobacillus thio oxidans. For comparison purpose some experiments have also been conducted by chemical leaching. The results of bacterial leaching are encouraging. (author)

THE BIOCATALYTIC DESULFURIZATION PROJECT

Energy Technology Data Exchange (ETDEWEB)

Scott Collins; David Nunn

2003-10-01

The analysis of Petro Star diesel sulfur species is complete and a report is attached. Further analytical efforts will concentrate on characterization of diesel fuel, hydrodesulfurized to varying degrees, in order to determine sulfur species that may be problematic to hydrogen treatment and represent potential target substrates for biodesulfurization in a combined HDS-BDS process. Quotes have been received and are being considered for the partial treatment of Petro Star Inc. marine diesel fuel. Direction of research is changing slightly; economic analysis of the hyphenated--BDSHDS, BDS-CED--has shown the highest probability of success to be with a BDS-HDS process where the biodesulfurization precedes hydrodesulfurization. Thus, the microorganisms will be tailored to focus on those compounds that tend to be recalcitrant to hydrodesulfurization and decrease the severity of the hydrodesulfurization step. A separate, detailed justification for this change is being prepared. Research activities have continued in the characterization of the desulfurization enzymes from multiple sources. Genes for all DszA, -B, -C and -D enzymes (and homologs) have been cloned and expressed. Activity determinations, on a variety of substituted benzothiophene and dibenzothiophene substrates, have been carried out and continue. In addition, chemical synthesis efforts have been carried out to generate additional substrates for analytical standards and activity determinations. The generation of a GSSM mutant library of the ''Rhodococcus IGTS8 dszA'' gene has been completed and development of protocols for a high throughput screen to expand substrate specificity are nearing completion. In an effort to obtain improved hosts as biocatalyst, one hundred-thirty ''Rhodococcus'' and related strains are being evaluated for growth characteristics and other criteria deemed important for an optimal biocatalyst strain. We have also begun an effort to generate

Influence of divalent metal ions on degradation of dimethylsulphide ...

African Journals Online (AJOL)

SERVER

2007-06-04

Jun 4, 2007 ... Dimethylsulphide degradation by intact cells of Thiobacillus thioparus TK-m was stimulated by the addition of divalent .... plastic vials in ice-cooled water. .... tization of authotrophic sulphur bacteria oxidizing dimethyldisulphide.

Biosuper as a phosphate fertilizer in a calcareous soil with low ...

African Journals Online (AJOL)

SERVER

2007-06-04

Jun 4, 2007 ... Key words: Zea mays, phosphorus uptake, phosphorus fertilization, corn, Thiobacillus, rock phosphate. ... improve plant nutrients availability in calcareous soils and .... lus elicits the reaction of sulphur with water and oxygen, ...

Biodesulfurization of dibenzothiophene and its alkylated derivatives ...

African Journals Online (AJOL)

RIPI-S81 is a new dibenzothiophene (DBT)-desulfurizing bacterium, which was isolated by Research Institute of Petroleum Industry in Iran. Resting cells and growing cells of RIPI-S81 was able to convert alkylated dibenzothiophenes (Cx DBTs) to hydroxybiphenyls such that they were almost stoichiometrically accumulated ...

Selection of mesophilic microorganisms with biodesulfuration capacity

International Nuclear Information System (INIS)

Madero, A; Mogollon, L. I; Mora, A.L; Osorio, L.F

1998-01-01

The development of bio desulfurization (BDS) processes for hydrocarbons requires fast and reliable methods for the screening of microorganisms. This work shows the results of the screening process for indigenous Colombian strains with a BDS potential capacity. The main criteria for the screening were the qualitative and quantitative determination of 2-hydroxybiphenyl (2-HBP) as the typical metabolite of the 4S specific pathway. Microorganisms were cultured by two methodologies, A and B, using DBT as the model compound. The quantitative determination of metabolites was made by HPLC. Thirteen strains were evaluated, including the strain Rhodococcus rhodocrous IGTS8, by methods A and B. In method A, the inoculum was exposed to DBT since the beginning of the culture. Method B, employed two stages: (i) Growth period under limiting sulfur conditions, (ii) Transforming period, in which the pre-grown inoculum was exposed to the organic sulfur substrate. The culture of mesophilic microorganisms isolated by method B, served to find a mechanism for the organic sulfur metabolism, and the evaluation of the sulfur removal capability of five indigenous strains. In the cultures of these strains, 2- hydroxybiphenyl (2-HBP) was detected as a byproduct of DBT metabolism, both qualitatively and quantitatively

Microbial- and Thiosulfate-Mediated Dissolution of Mercury Sulfide Minerals and Transformation to Gaseous Mercury

Directory of Open Access Journals (Sweden)

Adiari eVázquez-Rodríguez

2015-06-01

Full Text Available Mercury (Hg is a toxic heavy metal that poses significant human and environmental health risks. Soils and sediments, where Hg can exist as the Hg sulfide mineral metacinnabar (β-HgS, represent major Hg reservoirs in aquatic environments. Metacinnabar has historically been considered a sink for Hg in all but severely acidic environments, and thus disregarded as a potential source of Hg back to aqueous or gaseous pools. Here, we conducted a combination of field and laboratory incubations to identify the potential for metacinnabar as a source of dissolved Hg within near neutral pH environments and the underpinning (abiotic mechanisms at play. We show that the abundant and widespread sulfur-oxidizing bacterium Thiobacillus extensively colonized metacinnabar chips incubated within aerobic, near neutral pH creek sediments. Laboratory incubations of axenic Thiobacillus cultures lead to the release of metacinnabar-hosted Hg(II and subsequent volatilization to Hg(0. This dissolution and volatilization was greatly enhanced in the presence of the sulfur intermediate, thiosulfate, which served a dual role by enhancing HgS dissolution and providing an additional metabolic substrate for Thiobacillus. These findings reveal a new coupled abiotic-biotic pathway for the transformation of metacinnabar-bound Hg(II to Hg(0, while expanding the sulfide substrates available for neutrophilic chemosynthetic bacteria to Hg-laden sulfides. They also point to mineral-hosted Hg as an underappreciated source of gaseous elemental Hg to the environment.

Formation and colloidal behaviour of elemental sulphur produced from the biological oxidation of hydrogensulphide

NARCIS (Netherlands)

Janssen, A.J.H.

1996-01-01

The formation and aggregation of elemental sulphur from the microbiological oxidation of hydrogensulphide (H ₂ S) by a mixed population of aerobic Thiobacillus -like bacteria has been investigated. Sulphide is

Hydrogen Sulfide Removal from Air by Acidithiobacillus thiooxidans in a Trickle Bed Reactor

Czech Academy of Sciences Publication Activity Database

Ramirez, M.; Gómez, J. M.; Cantero, D.; Páca, J.; Halecký, M.; Kozliak, E. I.; Sobotka, Miroslav

2009-01-01

Roč. 54, č. 5 (2009), s. 409-414 ISSN 0015-5632 Institutional research plan: CEZ:AV0Z50200510 Keywords : 2-STAGE BIOTRICKLING FILTER * THIOBACILLUS-THIOPARUS * DIMETHYL SULFIDE Subject RIV: EE - Microbiology, Virology Impact factor: 0.978, year: 2009

Chemi-microbial processing of waste tire rubber: A project overview

International Nuclear Information System (INIS)

Romine, R.A.; Snowden-Swan, L.

1993-12-01

PNL is developing a method to use thiophillic microorganisms to devulcanize (biodesulfurize) the surface of ground rubber particles, which will improve the bonding and adhesion of the ground tire rubber into the virgin tire rubber matrix. The Chemi-microbial processing approach, introduced in this paper, is targeted at alleviating the waste tire problem in an environmentally conscious manner; it may also be applied to improve asphaltic materials and rubber and polymeric wastes to facilite their recycling. This paper outlines the logic and technical methods that will be used

ADVANCES IN BIOTREATMENT OF ACID MINE DRAINAGE AND BIORECOVERY OF METALS: 1. METAL PRECIPITATION FOR RECOVERY AND RECYCLE

Science.gov (United States)

Acid-mine drainage (AMD) is a severe pollution problem attributed to past mining activities. AMD is an acidic, metal-bearing wastewater generated by the oxidation of metal sulfides to sulfates by Thiobacillus bacteria in both active and abandoned mining operations. The wastewater...

Syntrophic growth of sulfate-reducing bacteria and colorless sulfur bacteria during oxygen limitation

NARCIS (Netherlands)

vandenEnde, FP; Meier, J; vanGemerden, H

Stable co-cultures of the sulfate-reducing bacterium Desulfovibrio desulfuricans PA2805 and the colorless sulfur bacterium Thiobacillus thioparus T5 were obtained in continuous cultures supplied with limiting amounts of lactate and oxygen while sulfate was present in excess. Neither species could

Enhanced fatty acid production in engineered chemolithoautotrophic bacteria using reduced sulfur compounds as energy sources

DEFF Research Database (Denmark)

Beller, Harry R.; Zhou, Peng; Jewell, Talia N.M.

2016-01-01

Chemolithoautotrophic bacteria that oxidize reduced sulfur compounds, such as H2S, while fixing CO2 are an untapped source of renewable bioproducts from sulfide-laden waste, such as municipal wastewater. In this study, we report engineering of the chemolithoautotrophic bacterium Thiobacillus...

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

... TEM which substantiated UV–Vis and XRD results. Photoluminescence spectroscopy detected the bacteria attachment to the QDs by showing significant blue shift in bacteria conjugated ZnS QDs. Fluorescence microscopy confirmed the fluorescent labelling of QDs to Thiobacillus novellus bacteria cells making them ideal ...

Microbial diversity and community structure in an antimony-rich tailings dump.

Science.gov (United States)

Xiao, Enzong; Krumins, Valdis; Dong, Yiran; Xiao, Tangfu; Ning, Zengping; Xiao, Qingxiang; Sun, Weimin

2016-09-01

To assess the impact of antimony (Sb) on microbial community structure, 12 samples were taken from an Sb tailings pile in Guizhou Province, Southwest China. All 12 samples exhibited elevated Sb concentrations, but the mobile and bioaccessible fractions were small in comparison to total Sb concentrations. Besides the geochemical analyses, microbial communities inhabiting the tailing samples were characterized to investigate the interplay between the microorganisms and environmental factors in mine tailings. In all samples, Proteobacteria and Actinobacteria were the most dominant phyla. At the genus level, Thiobacillus, Limnobacter, Nocardioides, Lysobacter, Phormidium, and Kaistobacter demonstrated relatively high abundances. The two most abundant genera, Thiobacillus and Limnobacter, are characterized as sulfur-oxidizing bacteria and thiosulfate-oxidizing bacteria, respectively, while the genus Lysobacter contains arsenic (As)-resistant bacteria. Canonical correspondence analysis (CCA) indicates that TOC and the sulfate to sulfide ratio strongly shaped the microbial communities, suggesting the influence of the environmental factors in the indigenous microbial communities.

LIXIVIACION BACTERIANA EN REACTORES: RECUPERACION DE COBRE A PARTIR DE CONCENTRADOS SULFURADOS.

OpenAIRE

CASAS DE PRADA, JESUS MANUEL

1991-01-01

Se estudió la cinética de lixiviación química (estéril) y bacteriana (con Thiobacillus ferrooxidans) de dos concentrados sulfurados de cobre, utilizando como agente oxidante el sulfato férrico en ambos casos. Los concentrados fueron suministrados por las 167p.

Effect of Rhodococcus sp. on desulfurization, swelling and extraction of coal

Energy Technology Data Exchange (ETDEWEB)

Wang De-qiang; Shui Heng-fu [University of Technology of Anhui, Maanshang (China). School of Chemical Engineering

2006-08-15

Bio-desulfurization of coal by rhodococcus sp. was studied. Some kinds of coal were swelled with different organic solvents, and then the swelled coals were treated by rhodococcus sp. The results show that the ratios of desulfurization of coals increase after they are swelled, especially swelled with NMP, the ratio is more than 80%. The swelling and extraction of coal were also studied after the coal had been treated by rhodococcus sp. The results show that the ratios of swelling increase more than 65%, but the extraction yield decreases for the coal treated by rhodococcus sp. 11 refs., 5 tabs.

Biotechnology bibliographies

Energy Technology Data Exchange (ETDEWEB)

Beaudette, L.A.; McCready, R.G.L.

1987-01-01

Four bibliographies are included in this document, covering articles and scientific papers from around the world written mostly in English. Citations are presented alphabetically by author under the topics of: acid mine drainage (coal and metals) and bioadsorption of metals; solution mining; metabolism and physiology of thiobacillus and other microorganisms; and bacterial leaching of metals.

Biotechnology bibliographies

Energy Technology Data Exchange (ETDEWEB)

Beaudette, L.A.; McCready, R.G.L.

1986-01-01

This bibliography consists of articles and scientific papers on biotechnology in areas in which BIOMINET is currently involved. The reports are categorized in four areas: 1) acid mine drainage (coals and metals) and bioadsorption of metals; 2) solution mining; 3) metabolism and physiology of Thiobacillus and other microorganisms; and 4) bacterial leaching of metals.

Bacteriological lixiviation of low-grade uranium ores at low temperatures, by phiobacillus ferrooxidaus

International Nuclear Information System (INIS)

Lobato Filho, A.N.S.

1976-12-01

Laboratory experiments are described that, using selective and mutagenic agents, allowed the isolation of a strain of thiobacillus ferrooxidams capable of developing at 8 0 C, and keeping its oxidesing characteristics tests showed that the isoled sample is capable of solubilizing 95% of the uranium content in samples with U 3 O 8 content below 1000ppm [pt

Research and Development of Methods for Estimating Physicochemical Properties of Organic Compounds of Environmental Concern. Part 1.

Science.gov (United States)

1981-06-01

involved. Many of the chemicals are insecticides, herbicides, fungicides , or compounds of re- lated structure. Aromatic and polynuclear aromatic hydrocarbons...Water Partition Coefficients," Proc. 7th British Insecticide and Fungicide Conf., Vol. 1, The Boots Company Ltd., Nottingham, G.B. (1973). 6. Browman...Peniciii um, Pseudomonae, Thiobacillus, Torulop’is, Trichoderma , Micro onospora, Streptomyces Marine Aquatic Achremobacter, Flavobacteriwn, [53] System

Treatments of acid waters; Tratamientos pasivos de aguas acidas

Energy Technology Data Exchange (ETDEWEB)

Delgado Fernandez, J. L.

2000-07-01

The exploitation of coal mining locations causes acid effluents due to the oxidation of the sulfurous minerals content of the rocks, denominated acid waters. There are Pyritic materials, pyres and sulphates associated to acid waters that in presence of water, oxygen and certain bacteria (mainly Thiobacillus ferro oxidants), are oxidized, by means of a chemistry reaction, yielding different products. (Author)

Recent Advances in Petroleum Microbiology

Science.gov (United States)

Van Hamme, Jonathan D.; Singh, Ajay; Ward, Owen P.

2003-01-01

Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times (desulfurization processes with biodesulfurization methods through promotion of selective sulfur removal without degradation of associated carbon moieties. However, since microbes require an environment containing some water, a two-phase oil-water system must be established to optimize contact between the microbes and the hydrocarbon, and such an emulsion is not easily created with viscous crude oil. This challenge may be circumvented by application of the technology to more refined gasoline and diesel substrates, where aqueous-hydrocarbon emulsions are more easily generated. Molecular approaches are being used to broaden the substrate specificity and increase the rates and extents of desulfurization. Bacterial processes are being commercialized for removal of H2S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and

Gasoline Biodesulfurization DE-FC07-97ID13570 FINAL REPORT

Energy Technology Data Exchange (ETDEWEB)

Pienkos, Philip T.

2002-01-15

Nine strains were identified to grow with gasoline as sole sulfur source. Two different genes were cloned from Gordonia terrae KGB1 and tested for the ability to support gasoline BDS. The first of these, fmoA, was cloned by screening a KGB1 gene library for the ability to convert indole to indigo (a sulfur-regulated capability in KGB1). The fmoA gene was overexpressed in a gasoline tolerant strain of Pseudomonas putida PpG1 and the recombinant strain was shown to convert thiophene to a dimer of thiophene sulfoxide at rates nearly two orders of magnitude higher than KGB1 could catalyze the reaction. Despite this high activity the recombinant PpG1 was unable to demonstrate any activity against gasoline either in shake flask or in bench-scale gasoline BDS bioreactor. A second gene (toeA) was cloned from KGB1 and shown to support growth of Rhodococcus erythropolis JB55 on gasoline. The toeA gene was also identified in another gasoline strain T. wratislaviensis EMT4, and was identified as a homolog of dszA from R. erythropolis IGTS8. Expression of this gene in JB55 supported conversion of DBTO2 (the natural substrate for DszA) to HPBS, but activity against gasoline was low and BDS results were inconsistent. It appeared that activity was directed against C2- and C3-thiophenes. Efforts to increase gene expression by plasmid manipulation, by addition of flavin reductase genes, or by expression in PpG1 were unsuccessful. The DszC protein (DBT monooxygenase) from IGTS8 has very little activity against the sulfur compounds in gasoline, but a mutant enzyme with a substitution of phenylalanine for valine at position 261 was shown to have an altered substrate range. This alteration resulted in increased activity against gasoline, with activity towards mainly C3- and C4-thiophenes and benzothiophene. A mutant library of dszB was constructed by RACHITT (W. C. Coco et al., DNA shuffling method for generating highly recombined genes and evolved enzymes. 2001. Nature Biotech. 19:354-359) method of in vitro recombination. Methods for analysis were developed and a preliminary analysis of the library was performed. A preliminary gasoline process design was constructed and process economics were determined based upon assumptions made from experimental results. The projected cost of gasoline BDS was determined to be competitive with current competing technologies.

Phospholipid anaysis of extant microbiota for monitoring in situ bioremediation effectiveness

International Nuclear Information System (INIS)

Pinkart, H.C.; Ringelberg, D.B.; Stair, J.O.; Sutton, S.D..; Pfiffner, S.M.; White, D.C.

1995-01-01

Two sites undergoing bioremediation were studied using the signature lipid biomarker (SLB) technique. This technique isolates microbial lipid moieties specifically related to viable biomass and to both prokaryotic and eukaryotic biosynthetic pathways. The first site was a South Pacific atoll heavily contaminated with petroleum hydrocarbons. The second site was a mine waste reclamation area. The SLB technique was applied to quantitate directly the viable biomass, community structure, and nutritional/physiological status of the microbiota in the soils and subsurface sediments of these sites. All depths sampled at the Kwajalein Atoll site showed an increase in biomass that correlated with the co-addition of air, water, and nutrients. Monoenoic fatty acids increased in abundance with the nutrient amendment, which suggested an increase in gram-negative bacterial population. Ratios of specific phospholipid fatty acids indicative of nutritional stress decreased with the nutrient amendment. Samples taken from the mine reclamation site showed increases in total microbial biomass and in Thiobacillus biomass in the plots treated with lime and bactericide, especially when a cover soil was added. The plot treated with bactericide and buffered lime without the cover soil showed some decrease in Thiobacillus numbers, but was still slightly higher than that observed in the control plots

Mixotrophy and chemiosmotic aspects of acidophilism in facultative thiobacilli

International Nuclear Information System (INIS)

Matin, A.

1984-01-01

Mixotrophic chemolithotrophs possess the unique potential of combining the use of autotrophic and heterotrophic growth substrates. This report discusses studies on dual substrate utilization by such organisms and recants the author's studies on mixotropy in Thiobacillus novellus using traditional batch cultures. It is concluded that although T. novellus can express its mixotrophic potential in both types of environments, this expression is complete and beneficial only under nutrient-limited conditions. 29 refs., 4 figs., 1 tab

Immobilisation of manganese, cobalt and nickel by deep-sea-sediment microbial communities

Digital Repository Service at National Institute of Oceanography (India)

Sujith, P.P.; Das, A.; Mourya, B.S.; LokaBharathi, P.A.

and their various organic derivatives in nature are contained in the living biomass. For example, Razzell and Trussell (1963) [9] addressed the interaction of Thiobacillus spp with sulfide baring ores and their role in dissolution of oxides and release... of valuable metals. Likewise, Fortin et al (1994), Basnakova and Macaskie (1996) [10-11] presented the contribution of bacteria in the formation of sulfide and phosphide minerals by chemical complexing with available constituent sulfide and phosphide groups...

Review biodepyritisation of coal

Energy Technology Data Exchange (ETDEWEB)

Acharya, C.; Sukla, L.B.; Misra, V.N. [Regional Research Lab., Orissa (India)

2004-01-01

This review provides a detailed summary of the recent and past research activities in the area of biodesulfurisation of coal. It provides information about microorganisms important for biodesulfurisation of coal, with the emphasis on Thiobacillus ferrooxidans. The review presents an insight into various methods of desulfurisation of coal combining physical and biological methods. Also, there are discussions on coal structure, distribution, mechanism and kinetics of pyrite oxidation and jarosite precipitation. Finally, areas requiring further research are identified.

Gasoline Biodesulfurization DE-FC07-97ID13570 FINAL REPORT; FINAL

International Nuclear Information System (INIS)

Pienkos, Philip T.

2002-01-01

Nine strains were identified to grow with gasoline as sole sulfur source. Two different genes were cloned from Gordonia terrae KGB1 and tested for the ability to support gasoline BDS. The first of these, fmoA, was cloned by screening a KGB1 gene library for the ability to convert indole to indigo (a sulfur-regulated capability in KGB1). The fmoA gene was overexpressed in a gasoline tolerant strain of Pseudomonas putida PpG1 and the recombinant strain was shown to convert thiophene to a dimer of thiophene sulfoxide at rates nearly two orders of magnitude higher than KGB1 could catalyze the reaction. Despite this high activity the recombinant PpG1 was unable to demonstrate any activity against gasoline either in shake flask or in bench-scale gasoline BDS bioreactor. A second gene (toeA) was cloned from KGB1 and shown to support growth of Rhodococcus erythropolis JB55 on gasoline. The toeA gene was also identified in another gasoline strain T. wratislaviensis EMT4, and was identified as a homolog of dszA from R. erythropolis IGTS8. Expression of this gene in JB55 supported conversion of DBTO2 (the natural substrate for DszA) to HPBS, but activity against gasoline was low and BDS results were inconsistent. It appeared that activity was directed against C2- and C3-thiophenes. Efforts to increase gene expression by plasmid manipulation, by addition of flavin reductase genes, or by expression in PpG1 were unsuccessful. The DszC protein (DBT monooxygenase) from IGTS8 has very little activity against the sulfur compounds in gasoline, but a mutant enzyme with a substitution of phenylalanine for valine at position 261 was shown to have an altered substrate range. This alteration resulted in increased activity against gasoline, with activity towards mainly C3- and C4-thiophenes and benzothiophene. A mutant library of dszB was constructed by RACHITT (W. C. Coco et al., DNA shuffling method for generating highly recombined genes and evolved enzymes. 2001. Nature Biotech. 19:354-359) method of in vitro recombination. Methods for analysis were developed and a preliminary analysis of the library was performed. A preliminary gasoline process design was constructed and process economics were determined based upon assumptions made from experimental results. The projected cost of gasoline BDS was determined to be competitive with current competing technologies

Inhibition of carbon disulfide on bio-desulfurization in the process of ...

African Journals Online (AJOL)

Biological desulfurization is a novel technology for the removal of hydrogen sulfide from some biogas or sour gas, in which there are always a certain amounts of carbon disulfide together with much hydrogen sulfide. Nowadays, carbon disulfide is found to have negative effect on the biological desulfurization, but seldom ...

Microbial biocatalyst developments to upgrade fossil fuels.

Science.gov (United States)

Kilbane, John J

2006-06-01

Steady increases in the average sulfur content of petroleum and stricter environmental regulations concerning the sulfur content have promoted studies of bioprocessing to upgrade fossil fuels. Bioprocesses can potentially provide a solution to the need for improved and expanded fuel upgrading worldwide, because bioprocesses for fuel upgrading do not require hydrogen and produce far less carbon dioxide than thermochemical processes. Recent advances have demonstrated that biodesulfurization is capable of removing sulfur from hydrotreated diesel to yield a product with an ultra-low sulfur concentration that meets current environmental regulations. However, the technology has not yet progressed beyond laboratory-scale testing, as more efficient biocatalysts are needed. Genetic studies to obtain improved biocatalysts for the selective removal of sulfur and nitrogen from petroleum provide the focus of current research efforts.

Cooperative research in coal liquefaction infratechnology and generic technology development: Final report, October 1, 1985 to December 31, 1986

Energy Technology Data Exchange (ETDEWEB)

Sendlein, L.V.A.

1987-06-29

During the first year of its research program, the Consortium for Fossil Fuel Liquefaction Science has made significant progress in many areas of coal liquefaction and coal structure research. Research topics for which substantial progress has been made include integrated coal structure and liquefaction studies, investigation of differential liquefaction processes, development and application of sophisticated techniques for structural analysis, computer analysis of multivariate data, biodesulfurization of coal, catalysis studies, co-processing of coal and crude oil, coal dissolution and extraction processes, coal depolymerization, determination of the liquefaction characteristics of many US coals for use in a liquefaction database, and completion of a retrospective technology assessment for direct coal liquefaction. These and related topics are discussed in considerably more detail in the remainder of this report. Individual projects are processed separately for the data base.

1994 - 1995 annual report of the NRC Biotechnology Research Institute

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

One of the roles of the Biotechnology Research Institute is to promote leading edge research and development in biotechnology and molecular biology as they relate to industries in the natural resource sectors. To this end, researchers work with industry to develop less polluting, more efficient and economic processes and to solve environmental problems. Scientific studies undertaken in 1994 and 1995 included new analytical techniques and biosensors, bioprocesses for waste and ground water treatment, biopesticides, biodegradation of toxic compounds, biodesulfurization of bitumen, solvent- less sample preparation techniques to analyze environmental pollutants in soils and waste water, protocol for the analysis of petroleum hydrocarbons, gene probes and their applications, biodegradation of energetic compounds, and biofiltration of air emissions. These, and other noteworthy projects undertaken by the Institute, were reviewed and presented ,combined with institutional data. 2 tabs.

Enrichment and immobilization of sulfide removal microbiota applied for environmental biological remediation of aquaculture area

International Nuclear Information System (INIS)

Zhao, Yang-Guo; Zheng, Yu; Tian, Weijun; Bai, Jie; Feng, Gong; Guo, Liang; Gao, Mengchun

2016-01-01

To remove sulfide in the deteriorating aquaculture sediment and water, sulfide-oxidizing microbiota was enriched from Jiaozhou Bay, China, by using sulfide-rich medium. Composition and structure of microbial communities in the enrichments were investigated by 16S rDNA molecular biotechniques. Results showed that microbial community structure continuously shifted and the abundance of sulfate reducing bacteria, i.e., Desulfobacterium, Desulfococcus and Desulfobacca apparently declined. Several halophile genera, Vibrio, Marinobacter, Pseudomonas, Prochlorococcus, Pediococcus and Thiobacillus predominated finally in the microbiota. The enriched microbiota was capable of removing a maximum of 1000 mg/L sulfide within 12 h with 10% inoculum at pH 7.0, 20–30 °C. After immobilized, the microbiota presented excellent resistance to impact and could completely remove 600 mg/L sulfide in 12 h. Moreover, the immobilized microbiota recovered well even recycled for five times. In conclusion, the immobilized sulfide-removing microbiota showed a quite promising application for biological restoring of sulfide-rich aquaculture environment. - Highlights: • A sulfide-oxidizing microbiota successfully enriched from aquaculture sediment. • Microbiota dominated by Vibrio, Marinobacter, Pseudomonas and Thiobacillus spp. • Sulfide-oxidizing microbiota removed sulfide at an average rate of 100 mg/(L·h). • Immobilized microbiota removed over 85% of sulfide even recycled for five times.

Underground bioleaching: extracting from low-grade ore

International Nuclear Information System (INIS)

McCready, R.G.L.

1986-01-01

In 1984, Denison Mines began a research and demonstration project on the engineering aspects of bacterial leaching of low-grade uranium ore at Elliot Lake. The leaching solution was acidic mine water enriched in bacterial nutrients and innoculated with Thiobacillus ferrooxidans. Leaching of one stope was found to be impeded by fungi of the genus penicillium. Although fungal growth on leaching stopes must be prevented, research is proceeding on the potential use of the fungi to concentrate uranium from bioleaching solutions

Isolation of Thiobacillus spp. and its application in the removal of ...

African Journals Online (AJOL)

uwerhiavwe

physiological-biochemical characteristics. Single and mixed cultures of the strains were used to carry ... The characteristics of the sludge sample. Characteristic. Te content. Method. Solid content (%). 5 ..... archaeal diversity of a mixed thermophilic bioleaching culture by. TGGE and FISH. Syst. Appl. Microbiol. 32: 501–513.

Microbially-Enhanced Redox Solution Reoxidation for Sour Natural Gas Sweetening

Energy Technology Data Exchange (ETDEWEB)

Kenneth Brezinsky

2008-01-15

The specific objective of this project are to advance the technology and improve the economics of the commercial iron-based chelate processes such as LO-CAT II and SulFerox process utilizing biologically enhanced reoxidation of the redox solutions used in these processes. The project is based on the use of chelated ferric iron as the catalyst for the production of elemental sulfur, and then oxidizing bacteria, such as Thiobacillus Ferrooxidans (ATCC 23270) as an oxidizer. The regeneration of Fe{sup 3+} - chelate is accomplished by the use of these same microbes under mild conditions at 25-30 C and at atmospheric pressure to minimize the chelate degradation process. The pH of the redox solution was observed to be a key process parameter. Other parameters such as temperature, total iron concentration, gas to liquid ratio and bacterial cell densities also influence the overall process. The second part of this project includes experimental data and a kinetic model of microbial H{sub 2}S removal from sour natural gas using thiobacillus species. In the experimental part, a series of experiments were conducted with a commercial chelated iron catalyst at pH ranges from 8.7 to 9.2 using a total iron concentration range from 925 ppm to 1050 ppm in the solution. Regeneration of the solution was carried out by passing air through the solution. Iron oxidizing bacteria were used at cell densities of 2.3 x 10{sup 7}cells/ml for optimum effective performance. In the modeling part, oxidation of Fe{sup 2+} ions by the iron oxidizing bacteria - Thiobacillus Ferrooxidans was studied for application to a continuous stirred tank reactor (CSTR). The factors that can directly affect the oxidation rate such as dilution rate, temperature, and pH were analyzed. The growth of the microorganism was assumed to follow Monod type of growth kinetics. Dilution rate had influence on the rate of oxidation of ferrous iron. Higher dilution rates caused washout of the biomass. The oxidation rate was

Shifts in microbial community composition and function in the acidification of a lead/zinc mine tailings.

Science.gov (United States)

Chen, Lin-Xing; Li, Jin-Tian; Chen, Ya-Ting; Huang, Li-Nan; Hua, Zheng-Shuang; Hu, Min; Shu, Wen-Sheng

2013-09-01

In an attempt to link the microbial community composition and function in mine tailings to the generation of acid mine drainage, we simultaneously explored the geochemistry and microbiology of six tailings collected from a lead/zinc mine, i.e. primary tailings (T1), slightly acidic tailings (T2), extremely acidic tailings (T3, T4 and T5) and orange-coloured oxidized tailings (T6). Geochemical results showed that the six tailings (from T1 to T6) likely represented sequential stages of the acidification process of the mine tailings. 16S rRNA pyrosequencing revealed a contrasting microbial composition between the six tailings: Proteobacteria-related sequences dominated T1-T3 with relative abundance ranging from 56 to 93%, whereas Ferroplasma-related sequences dominated T4-T6 with relative abundance ranging from 28 to 58%. Furthermore, metagenomic analysis of the microbial communities of T2 and T6 indicated that the genes encoding key enzymes for microbial carbon fixation, nitrogen fixation and sulfur oxidation in T2 were largely from Thiobacillus and Acidithiobacillus, Methylococcus capsulatus, and Thiobacillus denitrificans respectively; while those in T6 were mostly identified in Acidithiobacillus and Leptospirillum, Acidithiobacillus and Leptospirillum, and Acidithiobacillus respectively. The microbial communities in T2 and T6 harboured more genes suggesting diverse metabolic capacities for sulfur oxidation/heavy metal detoxification and tolerating low pH respectively. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

Optimization of low sulfur jerusalem artichoke juice for fossil fuels biodesulfurization process

OpenAIRE

Silva, Tiago P.; Paixão, Susana M.; Roseiro, J. Carlos; Alves, Luís Manuel

2013-01-01

Most of the world’s energy is generated from the burning of fossil fuels such as oil and its derivatives. When burnt, these fuels release into the atmosphere volatile organic compounds, sulfur as sulfur dioxide (SO2) and the fine particulate matter of metal sulfates. These are pollutants which can be responsible for bronchial irritation, asthma attacks, cardio-pulmonary diseases and lung cancer mortality, and they also contribute for the occurrence of acid rains and the increase of the hole i...

Microbial ecology of Rum Jungle, III. Leaching behaviour of sulphidic waste material under controlled conditions

International Nuclear Information System (INIS)

Babij, T.; Goodman, A.; Khalid, A.M.; Ralph, B.J.

1981-12-01

The discharge, into river systems, of acid and heavy metals generated by leaching of sulphidic waste materials at the abandoned opencut uranium mine at Rum Jungle, Northern Territory, is causing continuing pollution of the surrounding environment. The maximum effects of acid and microorganisms on samples from the overburden dump material, under defined and controlled environmental conditions, were assessed using reactor systems. These samples came from the overburden dump resulting from the mining of White's orebody. Similarly, the stability of tailings material under conditions of flooding and increasing acidity was determined. At ph 2.5, metals in White's dump material were solubilised by acid attack only, whereas at pH 3.5, bacterial activity (principally that of Thiobacillus ferrooxidans) generated acidity and contributed significantly to metal release. Under microaerophilic conditions Thiobacillus ferrooxidans continued to effect metal release from the ore, but did not produce further acidity. If White's overburden is returned to the acidic, flooded opencuts, complete solubilisation of the material will occur. The exclusion of oxygen from the dump will not necessarily stop bacterially catalysed leaching processes. Under highly aerated and agitated flooded conditions the tailings material was not active, except for copper release of about 2 g kg -1 ore at pH 4.0. The only deleterious element released by increasing acidity was copper, which was 100 per cent solubilised at pH 2.5. Uranium was always lss than 3 μg kg -1 ore, and lead was detected only at pH 2.5. Indigenous leaching bacteria did not develop

Bugs and coal: processing fuels with biotechnology

Energy Technology Data Exchange (ETDEWEB)

Shepard, M

1987-06-01

Bioprocessing of coal is developing along several fronts, each of potential significance to utilities. Researchers have found a fungus, polyporous versicolor, which can liquefy certain kinds of coal and scientists have genetically engineered bacteria that remove sulfur and ash-forming metal impurities from coal. Research programs are being undertaken to find organisms that will convert lignite into gaseous methane to produce gaseous fuel more economically than the current coal gasification methods. Researchers looking for ways to remove sulfur from coal before it is burned are evaluating the use of a bacterium called thiobacillus ferroxidans to enhance the physical removal of pyrite. 2 refs.

Application of microorganism to in-situ leaching mining

International Nuclear Information System (INIS)

Yu, Runlan; Sato, Kazuhiko; Nagara, Shuichi; Yamana, Satoshi

1998-01-01

In-situ leaching (ISL) technique has come into the spotlight recently because of its low production costs and low environmental impact. In China, development and application of economical ISL techniques are also being studied. To design a pilot scale ISL 'bioreactor' in China, applicability of microorganisms to ISL mining was evaluated at Ningyo Toge Works as a part of Scientist Exchange Program of the Science and Technology Agency. An overview of the indirect bio-ISL method with iron oxidizing bacteria, Thiobacillus ferroxidans (TF), and results from experiment to determine factors for the ISL 'bioreactor' are discussed. (author)

Modelling a uranium ore bioleaching process

International Nuclear Information System (INIS)

Chien, D.C.H.; Douglas, P.L.; Herman, D.H.; Marchbank, A.

1990-01-01

A dynamic simulation model for the bioleaching of uranium ore in a stope leaching process has been developed. The model incorporates design and operating conditions, reaction kinetics enhanced by Thiobacillus ferroxidans present in the leaching solution and transport properties. Model predictions agree well with experimental data with an average deviation of about ± 3%. The model is sensitive to small errors in the estimates of fragment size and ore grade. Because accurate estimates are difficult to obtain a parameter estimation approach was developed to update the value of fragment size and ore grade using on-line plant information

Anaerobic degradation of methanethiol in a process for Liquefied Petroleum Gas (LPG) biodesulfurization

NARCIS (Netherlands)

Leerdam, van R.C.

2007-01-01

Due to increasingly stringent environmental legislation car fuels have to be desulfurized to levels below 10 ppm in order to minimize negative effects on the environment as sulfur-containing emissions contribute to acid deposition (‘acid rain’) and to reduce the amount of particulates formed during

Biodecontamination of concrete

International Nuclear Information System (INIS)

Hamilton, M.A.; Rogers, R.D.; Benson, J.

1996-01-01

A novel technology for biologically decontaminating concrete is being jointly developed by scientists at the Idaho National Engineering Laboratory (INEL) and British Nuclear Fuels plc (BNFL). The technology exploits a naturally occurring phenomenon referred to as microbially influenced degradation (MID) in which bacteria produce acids that dissolve the cement matrix of concrete. Most radionuclide contamination of concrete is fixed in the outer few mm of the concrete surface. By capturing and controlling this natural process, a biological method of removing the surface of concrete to depths up to several mm is being developed. Three types of bacteria are known to be important in MID of concrete: nitrifying bacteria that produce nitric acid, sulfur oxidizing bacteria that produce sulfuric acid, and certain heterotrophic bacteria that produce organic acids. An investigation of natural environments demonstrated with scanning electron microscopy the presence of bacteria on concrete surfaces of a variety of structures, such as bridges and dams, where corrosion is evident. Enumeration of sulfur oxidizing and nitrifying bacteria revealed their presence and activity on structures to varying degrees in different environments. Under ideal conditions, Thiobacillus thiooxidans, a sulfur oxidizing bacteria, attached to and colonized the surface of concrete specimens. Over 1mm depth of material from a 10 cm x 10 cm square surface was removed in 68 days in the Thiobacillus treated specimen compared to a sterile control. Laboratory and field demonstrations are currently being conducted using experimental chambers designed to be mounted directly to concrete surfaces where radionuclide contamination exists. Data is being obtained in order to determine actual rates of surface removal and limitations to the system. This information will be used to develop a full scale decontamination technology

Waste pyritic coal as a raw material for energetic industry

Energy Technology Data Exchange (ETDEWEB)

Gasiorek, J. [Institute of Inorganic Chemistry, Poznan (Poland). Dept. of Research and Technology

1997-11-01

Results are presented of large laboratory studies on coal desulphurisation with foam flotation method improved by application of bioadsorption of Thiobacillus ferrooxidans bacteria to the modification of superficial properties of pyrite particulates from hydrophobic to hydrophillic ones. Results of coal desulfurization with and without bioadsorption have been compared. Bioadsorption improved pyritic sulfur removal by 30% (for coal from `Sierza mine`, coal size 0.3 to 0.102 mm, S pyritic content 1.69%) after 6-week adaptation of bacteria and 30 min of bioadsorption. Bacteria concentration in 5% water suspension of coal reached 22 {mu}g of biomass cm{sup -3}. 12 refs., 4 figs., 1 tab.

Application of bacterial leaching technology to deep solution-mining conditions for uranium extraction. Final report, September 1, 1978-September 30, 1981

International Nuclear Information System (INIS)

Brierley, J.A.; Brierley, C.L.; Torma, A.E.

1982-03-01

Microorganisms were evaluated for use in recovery of uranium under conditions of in-situ solution mining. The cultures tested were Thiobacillus ferrooxidans, the faculative-thermophilic TH3 strain, and two Sulfolobus species. Growth of the organisms occurred in the presence of 0.34 to 5.0 mM uranyl ion with higher concentrations being inhibitory. Uranium ore from the Anaconda Minerals Co. Jackpile mine was not readily leachable by microorganisms. To support bacterial activity the ore was supplemented with pyrite or ferrous iron. The ore possessed some toxic properties. T. ferrooxidans was able to assist in leaching of uranium from the ore at a hydrostatic pressure of 10.3 MPa

Research within the coordinated progamme on bacterial leaching of uranium ores

International Nuclear Information System (INIS)

Marjanovic, D.

1978-01-01

Effect of magnetic field on the growth rate of Thiobacillus ferrooxidans bacteria was studied at intensities of 30, 100, 2400, and 4000 Oe. Low intensity magnetic field was found to stimulate the bacteria growth rate and the rate of ferrosulphate oxidation with optimum values at 30 to 300 Oe (maximum at 300 Oe). Magnetic field of high intensity (2400, 3200, 4000 Oe) inhibits the growth of bacteria and processes of bacterial oxidation. The possibility was also studied of using biocides for inhibiting bacterial processes in uranium-bearing waste dumps. The use of biocides resulted in a decrease of uranium-bearing waste dump autochthonous microflora density

Chemical and microbiological problems associated with research on the biodesulfurization of coal. A review

Energy Technology Data Exchange (ETDEWEB)

Olson, G J; Kelly, R M [National Institute of Standards and Technology, Gaithersburg, MD (USA). Polymer Division

1991-04-01

The study of microbial processes for the removal of organic and inorganic sulfur from coals is complicated by the lack of direct methods of measurement for organic sulfur content and the related incomplete understanding of the specific forms of organic sulfur in coal. In addition, the accessibility of specific chemical groups in the coal matrix to microorganisms and their enzymes is uncertain, raising questions about the nature and validity of model compound studies. Thus, interpretation of data from numerous efforts focussed on the microbial removal of inorganic and organic sulfur from coals remains controversial. The discussion here reviews recent developments in the chemical characterization of coal sulfur related to bioprocessing research and describes some recent efforts in involving sulfur transformation by hyperthermophilic archaebacteria. 26 refs., 4 figs., 1 tab.

EVALUATION OF A COAL BIODESULFURIZATION PROCESS (SEMI-CONTINUOUS MODE ON THE PILOT PLANT LEVEL

Directory of Open Access Journals (Sweden)

GERARDO CAICEDO

2012-01-01

Full Text Available En un reactor de tanque agitado con capacidad de 4000 L, se llevó a cabo un proceso de biodesulfurización de un carbón con alto contenido de azufre (Spirítico = 1.03%, Sorgánico = 0.9%, Ssulfatos = 0.1%, proveniente del Municipio de Puerto Libertador (Córdoba, Colombia. Se utilizó un cultivo bacteriano compatible con A. ferrooxidans y A. thiooxidans. Se configuró un sistema de descarga-carga bajo condiciones ambientales, pH controlado diariamente (1.8±0.1, oxígeno disuelto 4 mg/l y tamaño de partícula pasante 3/8" (dp<19.05 mm. Se evaluaron dos tiempos de residencia (C2 = 8 días y C1 = 4 días. La máxima oxidación de pirita fue de 59.22% (C1. Lo anterior muestra buenas expectativas del proceso sin llevarse el carbón a molienda fina. Por otra parte, los efluentes líquidos producidos durante la biodesulfurización fueron neutralizados con cal antes de ser descartados a un pH entre 7.5-8.5, observándose remociones del 100% de hierro, 69.81% de sulfatos y 66.09% de los sólidos totales en solución.

Model description of dibenzothiophene mass transfer in oil/water dispersions with respect to biodesulfurization

NARCIS (Netherlands)

Marcelis, C.L.M.; Leeuwen, van M.; Polderman, H.G.; Janssen, A.J.H.; Lettinga, G.

2003-01-01

A mathematical model was developed in order to describe the mass transfer rate of dibenzothiophene within the oil droplet to the oil/water interface of droplets created in a stirred tank reactor. The mass transfer rate of dibenzothiophene was calculated for various complex hydrocarbon distillates

Isolation and characterization of cbbL and cbbS genes encoding form I ribulose-1,5-bisphosphate carboxylase/oxygenase large and small subunits in Nitrosomonas sp. strain ENI-11.

Science.gov (United States)

Hirota, Ryuichi; Kato, Junichi; Morita, Hiromu; Kuroda, Akio; Ikeda, Tsukasa; Takiguchi, Noboru; Ohtake, Hisao

2002-03-01

The cbbL and cbbS genes encoding form I ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large and small subunits in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11 were cloned and sequenced. The deduced gene products, CbbL and CbbS, had 93 and 87% identity with Thiobacillus intermedius CbbL and Nitrobacter winogradskyi CbbS, respectively. Expression of cbbL and cbbS in Escherichia coli led to the detection of RubisCO activity in the presence of 0.1 mM isopropyl-beta-D-thiogalactopyranoside (IPTG). To our knowledge, this is the first paper to report the genes involved in the carbon fixation reaction in chemolithotrophic ammonia-oxidizing bacteria.

Utilization of low grade and waste uranium ores by means of biological processes. Part of a coordinated programme on bacterial leaching of uranium ores

International Nuclear Information System (INIS)

Czegledi, B.

1978-01-01

Investigation of the possible affect of bacteria in leaching uranium using alkaline carbonate medium has been investigated. Eleven strains of bacteria were isolated from the alkaline percolation solutions. Most belonged to the genus Thiobacillus. Each strain was characterized by growth under aerobic conditions in Levinthal - bouillon medium and under vaseline (semi-anaerobic in Hetehens medium. Growth of the bacteria was optimum at pH range 7 to 8 but a significant population was found to exist in alkaline leaching solutions of about pH 9 to 9.5 in heap leaching experiments. It was concluded that microbiological processes can play a role in alkaline heap leaching although the quantitative measure is yet uncertain

Bioleaching of a manganese and silver Ore

International Nuclear Information System (INIS)

Porro, S.; Tedesco, P.H.; La Plata

1990-01-01

The bioleaching with a strain of Thiobacillus thiooxidans of the ore of Farallon Negro (Catamarca, Argentina) was studied in order to estimate its application to the solution and recovery of the manganese, and to improve the silver extraction. The State company which works the mine has not yet found an economical process to extract the manganese and has only reached a 30% efficiency in the recovery of silver by cianuration. The effects of pulp density variations and the addition of different quantities of FeS were analysed looking for the best working conditions. 74 μm (mesh Tyler 200) of ore particles were used because that is the size used in this plant for the cianuration process. (Author)

Investigations on microbial leaching of zircon by means of spark source mass spectrometry

International Nuclear Information System (INIS)

Becker, S.; Dietze, H.J.; Bullmann, M.; Iske, U.

1985-01-01

Spark source mass spectrometry is a useful method for chemical element analysis of geological and biological samples. This sensitive technique (detection limit down to the ppb-range) is used to analyze leaching processes by means of several microorganisms. The problem of microbial leaching of chemical resistent materials was tested under laboratory condition with regard to possible analytical and technical applications. Leaching of metalls with chemolithotrophic and heterotrophic, organic acids producing microorganisms has been investigated with zircon from Baltic Shield containing 0.7% rare earth elements and 1.67% hafnium. When zircon is leached with strains of Thiobacillus ferroxidans the rare earth elements, Hf, Th, and U mostly (about 80%) can be recovered. (author)

Mass spectrographic analysis of selected chemical elements by microbial leaching of zircon

International Nuclear Information System (INIS)

Becker, S.; Dietze, H.J.; Bullmann, M.; Iske, U.

1986-01-01

Spark source mass spectrometry is a useful method for chemical element analysis of geological and biological samples. This sensitive technique (detection limit down to the ppb-range) is used to analyze leaching processes by means of several microorganisms. The problem of microbial leaching of chemical resistent materials was tested under laboratory conditions with regard to possible analytical and technical applications. Leaching of metals with chemolithotrophic and heterotrophic, organic acids producing microorganisms has been investigated with zircon from the Baltic Shield containing 0.7% rare earth elements and 1.67% hafnium. When zircon is leached with strains of thiobacillus ferrooxidans about 80% of the rare earth elements, Hf, Th and U can be recovered. (orig.) [de

Dicty_cDB: Contig-U05414-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available NA clone ZM... 76 1e-18 CP001071_756( CP001071 |pid:none) Akkermansia muciniphila ATCC BAA... 89 1e-18 AE017...CP000472 |pid:none) Shewanella piezotolerans WP3, com... 92 2e-17 AM286415_3721( AM286415 |pid:none) Yersini...lin,... 50 2e-06 AM494945_19( AM494945 |pid:none) Leishmania braziliensis chromosom... 55 5e-06 AP00725...0_22( DQ226510 |pid:none) Thellungiella halophila clone ThB... 94 2e-23 CP000116_2432( CP000116 |pid:none) Thiobacillus denitrificans...-17 CP000934_3554( CP000934 |pid:none) Cellvibrio japonicus Ueda107, c... 83 3e-17 AB274914_1( AB274914 |pid:none) Pleurochrysi

Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

International Nuclear Information System (INIS)

Rouas, C.

1988-12-01

A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry [fr

Selection and Application of Sulfide Oxidizing Microorganisms Able to Withstand Thiols in Gas Biodesulfurization Systems

NARCIS (Netherlands)

Roman, Pawel; Klok, Johannes B.M.; Bastos Sousa, Joao; Broman, Elias; Dopson, Mark; Zessen, van Erik; Bijmans, Martijn F.M.; Sorokin, Dimitry Y.; Janssen, Albert J.H.

2016-01-01

After the first commercial applications of a new biological process for the removal of hydrogen sulfide (H₂S) from low pressure biogas, the need arose to broaden the operating window to also enable the removal of organosulfur compounds from high pressure sour gases. In this study we

Fractionation of sulfur isotopes in the chemical and biochemical oxidation of sulfide to sulfate

International Nuclear Information System (INIS)

Maass, I.; Wetzel, K.; Weise, G.; Heyer, J.

1983-01-01

The behaviour of sulfur isotopes in the chemical and biochemical oxidation of marcasite (FeS 2 ) to sulfate has been investigated in rest and shaker cultures at 30 0 C. The microbiological oxidation was carried out using a mixed culture of Thiobacillus. The results show a considerably faster formation of sulfate in the biochemical oxidation in comparison with the chemical oxidation. Isotope analyses of the formed sulfates indicate no or only very small isotope fractionations depending on experimental conditions. The highest enrichment of 32 S in the sulfate is 1.7 per mille. In accordance with the results of other authors it is concluded that in both chemical and biochemical weathering of sedimentary sulfides resulting in the formation of sulfates isotope effects are not of importance. (author)

Molecular and biochemical characterization of a highly stable bacterial laccase that occurs as a structural component of the Bacillus subtilis endospore coat.

Science.gov (United States)

Martins, Ligia O; Soares, Claudio M; Pereira, Manuela M; Teixeira, Miguel; Costa, Teresa; Jones, George H; Henriques, Adriano O

2002-05-24

The Bacillus subtilis endospore coat protein CotA shows laccase activity. By using comparative modeling techniques, we were able to derive a model for CotA based on the known x-ray structures of zucchini ascorbate oxidase and Cuprinus cereneus laccase. This model of CotA contains all the structural features of a laccase, including the reactive surface-exposed copper center (T1) and two buried copper centers (T2 and T3). Single amino acid substitutions in the CotA T1 copper center (H497A, or M502L) did not prevent assembly of the mutant proteins into the coat and did not alter the pattern of extractable coat polypeptides. However, in contrast to a wild type strain, both mutants produced unpigmented colonies and spores unable to oxidize syringaldazine (SGZ) and 2'2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The CotA protein was purified to homogeneity from an overproducing Escherichia coli strain. The purified CotA shows an absorbance and a EPR spectra typical of blue multicopper oxidases. Optimal enzymatic activity was found at < or =pH 3.0 and at pH 7.0 for ABTS or SGZ oxidation, respectively. The apparent K(m) values for ABTS and SGZ at 37 degrees C were of 106 +/- 11 and 26 +/- 2 microm, respectively, with corresponding k(cat) values of 16.8 +/- 0.8 and 3.7 +/- 0.1 s(-1). Maximal enzyme activity was observed at 75 degrees C with ABTS as substrate. Remarkably, the coat-associated or the purified enzyme showed a half-life of inactivation at 80 degrees C of about 4 and 2 h, respectively, indicating that CotA is intrinsically highly thermostable.

Mutualism between autotrophic and heterophic bacteria in leaching of low grade ores

International Nuclear Information System (INIS)

Khalid, Z.M.; Naeveke, R.

1991-01-01

During solubilization processes of low grade sulphidic ores, the auto trophic bacteria oxidize reduced sulphur compounds and ferrous iron to sulphates and ferric iron respectively. The ore leaching bio topes are not only colonized by auto trophic bacteria (Thiobacillus spp., Leptospirillum ferro oxidans and sulfolobus sp.) but the heterotrophic microorganisms, including bacteria and fungi of various species are also found in these habitats. The autotrophs, in addition to energy metabolism, also produce organic compounds which in excess amount inhibit their growth. Through the utilization of such compounds and also through the production of carbon dioxide and ammonia, these heterotorphs can help bio leaching processes. Effect of one of the heterotrophs; methylobacterium sp., a nitrogen scavenger, found in as association with the thio bacilli in one of the leaching bio tope in Germany was studied in leaching of a carbonate bearing complex (containing copper, iron, zinc and lead) sulphidic ore, in shake flask studies. T. ferro oxidans (Strain F-40) reported to be non nitrogen fixer and strain F-41, a nitrogen fixing thiobacillus were studied for leachability behaviour alone and in combination with T. thio oxidans (lacking nitrogen fixing ability) using media with and without added ammonium nitrogen. In addition the effect of methylobacterium sp. (alt-25) was also tested with the afore mentioned combinations. Nitrogen fixation by T. ferro oxidans did not suffice the nitrogen requirement and the leaching system in laboratory needed addition of nitrogen. The heterotrophic nitrogen scavenger also did not have a positive influence in nitrogen limited system. In case where ammonium nitrogen was also provided in the media, this heterotroph had a negative in own growth and leaving lesser amount available for thio bacilli. This high amount of acid is a limiting factor in bio leaching of high carbonate uranium ores. Uranium ore ecosystems have also been found to contain

Anaerobic microbiological method of cleaning water contaminated by metallurgical slags

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Олена Леонідівна Дан

2015-11-01

Full Text Available The problem of environmental protection and rational use of water resources is one of the most important problems of environmental policy in Ukraine. This problem in Mariupol is particularly acute as metallurgical and coke industries cause significant damage to adjacent water bodies (the Kalchyk, the Kalmius and coastal zone of the Sea of Azov. One of the most harmful components of wastewater of these enterprises are sulfide-containing compounds. These compounds in water can cause great harm to both human health and the environment. For example, in 1999 the main city enterprises (AZOVSTAL IRON & STEEL WORKS and ILYICH IRON AND STEEL WORKS discharged 885,0 million m³ of wastewater (including 403,9 million m³ of polluted waste water into water bodies. The slag dumps and landfills in close proximity to the sea form a source of dangerous pollution, because contaminated water infiltration washed out here in the groundwater and surface water, get into the Sea of Azov later on. There are 97 mg/l of sulfides in the protective dam of AZOVSTAL IRON & STEEL WORKS, what exceeds the standards (MPC = 10 mg/l. It makes it possible for us to put forward biochemical purification processes. Anaerobic microbiological method proposed in the article has several advantages (compact hardware design, a minimum amount of activated sludge and lack of energy consumption for aeration over the existing wastewater treatment (chemical, mechanical, biological. The experimental procedure consisted in introducing the medium to be purified purified into microbial communities of high concentration (Thiobacillus «X», Thiobacillus concretivorus, which assimilated organic substances of the medium as a primary energy source. The kinetics of sulfide compounds removal by means of anaerobic microbiological method was considered. The effectiveness of wastewater treatment with changing purification process conditions has been also assessed (concentration of sulfides, reactor type, p

Effect of oil pollution on pattern and functions of soil microbiosensors

International Nuclear Information System (INIS)

Talibli, A.K.; Mamedova, I.S.; Mamedyarov, M.A.

2002-01-01

Full text : The soil polluted by oil and petroleum creates severe social and ecological problem. The solution of indicated problem is requires the development and intrusion of modern progressive technology. Most perspective in this sense can be clearing the oil-polluted soils with usage of activity of microorganisms. The modern level of learning of microorganisms oxidizing oil hydrocarbon testifies to a capability of creation of the non-polluting, economically effective biotechnological schemes. It was established by our researches that in oil polluted soils of Absheron peninsula alongside with hydrocarbon oxidizing bacteria it is finding everywhere lithotrophic bacteria of cycle of sulfur - representatives of sulfate-reducing and bacteria of genus Thiobacillus. It was established that the soil polluted by heavy tarry oil renders negative influencing on development of microorganisms

Acidophiles of saline water at thermal vents of Vulcano, Italy.

Science.gov (United States)

Simmons, Susan; Norris, R

2002-06-01

DNA was extracted from samples taken from close to acidic hydrothermal vents on shore of the Aeolian Island of Vulcano (Italy). RNA gene sequences were amplified by PCR, cloned, and sequenced. A sequence with an origin in samples at 35 degrees and 45 degrees C corresponded to that of a novel Acidithiobacillus species that was isolated from water close to the vents. Novel, iron-oxidizing mesophilic acidophiles were isolated through enrichment cultures with ferrous iron but were not represented in the clone banks of environmental rDNA. These acidophiles were related to Thiobacillus prosperus, which was isolated previously from Vulcano. The archaeal sequences that comprised a clone bank representing a high-temperature sample (75 degrees C) corresponded to those of Acidianus brierleyi and of thermophiles previously isolated from Vulcano, Thermoplasma volcanium and Acidianus infernus.

Definition of a concrete bio-decontamination process in nuclear substructures; Biodegradation de matrices cimentaires en vue de leur decontamination

Energy Technology Data Exchange (ETDEWEB)

Jestin, A

2005-05-15

The decontamination of sub-structural materials represents a stake of high-importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those micro-organisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

Biodegradation of concrete intended for their decontamination; Biodegradation de matrices cimentaires en vue de leur decontamination

Energy Technology Data Exchange (ETDEWEB)

Jestin, A

2005-05-15

The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

Heap leaching for uranium

International Nuclear Information System (INIS)

1988-01-01

Denison Mines Ltd. is using two bacterial leaching processes to combat the high cost of extracting uranium from low grade ore in thin reefs. Both processes use thiobacillus ferro-oxidans, a bacterium that employs the oxidation of ferrous iron and sulphur as its source of energy for growth. The first method is flood leaching, in which ore is subjected to successive flood, drain and rest cycles. The second, trickle leaching, uses sprinklers to douse the broken muck continuously with leaching solution. In areas where grades are too low to justify the expense of hauling the ore to the surface, the company is using this biological process underground to recover uranium. In 1987 Denison recovered 840 000 lb of uranium through bacterial heap leaching. It plans to have biological in-place leaching contribute 25% of the total uranium production by 1990. (fig.)

Definition of a concrete bio-decontamination process in nuclear substructures

International Nuclear Information System (INIS)

Jestin, A.

2005-05-01

The decontamination of sub-structural materials represents a stake of high-importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those micro-organisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

Biodegradation of concrete intended for their decontamination

International Nuclear Information System (INIS)

Jestin, A.

2005-05-01

The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

Microbial detoxification of waste rubber material by wood-rotting fungi.

Science.gov (United States)

Bredberg, Katarina; Andersson, B Erik; Landfors, Eva; Holst, Olle

2002-07-01

The extensive use of rubber products, mainly tires, and the difficulties to recycle those products, has resulted in world wide environmental problems. Microbial devulcanisation is a promising way to increase the recycling of rubber materials. One obstacle is that several microorganisms tested for devulcanisation are sensitive to rubber additives. A way to overcome this might be to detoxify the rubber material with fungi prior to the devulcanisation. In this study, 15 species of white-rot and brown-rot fungi have been screened with regard to their capacity to degrade an aromatic model compound in the presence of ground waste tire rubber. The most effective fungus, Resinicium bicolor, was used for detoxification of rubber material. Increase in growth of the desulfurising bacterium Thiobacillus ferrooxidans in presence of the rubber treated with Resinicium bicolor compared to untreated rubber demonstrated that detoxification with fungi is possible.

THE BIOCATALYTIC DESULFURIZATION PROJECT

Energy Technology Data Exchange (ETDEWEB)

Steven E. Bonde; David Nunn

2003-04-01

Research activities in the second quarter have largely been a continuation of efforts previously described in the first quarterly report as well as a degree of redirection of effort as a result of discussions during the first quarterly meeting held in San Diego. Chemical synthesis efforts have been refined and are currently being used to support generation of substrates for evaluation and evolution of enzymes for their oxidation. Analysis of the sulfur species in Petro Star diesel, CED extract and refinement of the speciation data is nearly complete. Molecular biology efforts continue with the cloning, expression and characterization of the DszA and DszC proteins as well as the flavin reductases to support regeneration of the essential FMN cofactors. In addition, we have initiated an evolution effort for the extension and improvement of DszA enzyme activity using Diversa's Gene Site Saturation Mutagenesis (GSSM{trademark}) technology. To support the evolution effort as well as of characterization of enzyme activities on a variety of substrates, a high-throughput mass spectroscopy-based assay has been developed. Two selection/screen strategies for the discovery and evolution of biocatalyst enzyme have been developed and are being evaluated for performance using gene libraries constructed from known biodesulfurization strains and environmental libraries.

Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia: Mollusca).

Science.gov (United States)

Cavanaugh, C M; Abbott, M S; Veenhuis, M

1988-10-01

The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP(2)Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large subunit of RbuP(2)Case from tobacco (Nicotiana tabacum) cross-reacted on immunoblots with a protein of similar molecular mass occurring in extracts of the symbiont-containing gill tissue of S. velum. No cross-reactivity was detected in symbiont-free tissue extracts. The antiserum also cross-reacted in immunoblots with proteins of Thiobacillus neapolitanus, a free-living sulfuroxidizing chemoautotroph whose RbuP(2)Case has been well characterized. In protein A-gold immunoelectron microscopy studies, this antiserum consistently labeled the symbionts but not surrounding host gill tissue, indicating that the symbionts are responsible for the RbuP(2)Case activity.

Inhibitory effect of self-generated extracellular dissolved organic carbon on carbon dioxide fixation in sulfur-oxidizing bacteria during a chemoautotrophic cultivation process and its elimination.

Science.gov (United States)

Wang, Ya-Nan; Tsang, Yiu Fai; Wang, Lei; Fu, Xiaohua; Hu, Jiajun; Li, Huan; Le, Yiquan

2018-03-01

The features of extracellular dissolved organic carbon (EDOC) generation in two typical aerobic sulfur-oxidizing bacteria (Thiobacillus thioparus DSM 505 and Halothiobacillus neapolitanus DSM 15147) and its impact on CO 2 fixation during chemoautotrophic cultivation process were investigated. The results showed that EDOC accumulated in both strains during CO 2 fixation process. Large molecular weight (MW) EDOC derived from cell lysis and decay was dominant during the entire process in DSM 505, whereas small MW EDOC accounted for a large proportion during initial and middle stages of DSM 15147 as its cytoskeleton synthesis rate did not keep up with CO 2 assimilation rate. The self-generated EDOC feedback repressed cbb gene transcription and thus decreased total bacterial cell number and CO 2 fixation yield in both strains, but DSM 505 was more sensitive to this inhibition effect. Moreover, the membrane bioreactor effectively decreased the EDOC/TOC ratio and improved carbon fixation yield of DSM 505. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial community analysis in rice paddy soils irrigated by acid mine drainage contaminated water.

Science.gov (United States)

Sun, Min; Xiao, Tangfu; Ning, Zengping; Xiao, Enzong; Sun, Weimin

2015-03-01

Five rice paddy soils located in southwest China were selected for geochemical and microbial community analysis. These rice fields were irrigated with river water which was contaminated by Fe-S-rich acid mine drainage. Microbial communities were characterized by high-throughput sequencing, which showed 39 different phyla/groups in these samples. Among these phyla/groups, Proteobacteria was the most abundant phylum in all samples. Chloroflexi, Acidobacteria, Nitrospirae, and Bacteroidetes exhibited higher relative abundances than other phyla. A number of rare and candidate phyla were also detected. Moreover, canonical correspondence analysis suggested that pH, sulfate, and nitrate were significant factors that shaped the microbial community structure. In addition, a wide diversity of Fe- and S-related bacteria, such as GOUTA19, Shewanella, Geobacter, Desulfobacca, Thiobacillus, Desulfobacterium, and Anaeromyxobacter, might be responsible for biogeochemical Fe and S cycles in the tested rice paddy soils. Among the dominant genera, GOUTA19 and Shewanella were seldom detected in rice paddy soils.

Performance of denitrifying microbial fuel cell with biocathode over nitrite

Directory of Open Access Journals (Sweden)

Zhao eHuimin

2016-03-01

Full Text Available Microbial fuel cell (MFC with nitrite as an electron acceptor in cathode provided a new technology for nitrogen removal and electricity production simultaneously. The influences of influent nitrite concentration and external resistance on the performance of denitrifying MFC were investigated. The optimal effectiveness were obtained with the maximum total nitrogen (TN removal rate of 54.80±0.01 g m-3 d-1. It would be rather desirable for the TN removal than electricity generation at lower external resistance. Denaturing gradient gel electrophoresis suggested that Proteobacteria was the predominant phylum, accounting for 35.72%. Thiobacillus and Afipia might benefit to nitrite removal. The presence of nitrifying Devosia indicated that nitrite was oxidized to nitrate via a biochemical mechanism in the cathode. Ignavibacterium and Anaerolineaceae was found in the cathode as a heterotrophic bacterium with sodium acetate as substrate, which illustrated that sodium acetate in anode was likely permeated through proton exchange membrane to the cathode .

Bacterial community compositions of coking wastewater treatment plants in steel industry revealed by Illumina high-throughput sequencing.

Science.gov (United States)

Ma, Qiao; Qu, Yuanyuan; Shen, Wenli; Zhang, Zhaojing; Wang, Jingwei; Liu, Ziyan; Li, Duanxing; Li, Huijie; Zhou, Jiti

2015-03-01

In this study, Illumina high-throughput sequencing was used to reveal the community structures of nine coking wastewater treatment plants (CWWTPs) in China for the first time. The sludge systems exhibited a similar community composition at each taxonomic level. Compared to previous studies, some of the core genera in municipal wastewater treatment plants such as Zoogloea, Prosthecobacter and Gp6 were detected as minor species. Thiobacillus (20.83%), Comamonas (6.58%), Thauera (4.02%), Azoarcus (7.78%) and Rhodoplanes (1.42%) were the dominant genera shared by at least six CWWTPs. The percentages of autotrophic ammonia-oxidizing bacteria and nitrite-oxidizing bacteria were unexpectedly low, which were verified by both real-time PCR and fluorescence in situ hybridization analyses. Hierarchical clustering and canonical correspondence analysis indicated that operation mode, flow rate and temperature might be the key factors in community formation. This study provides new insights into our understanding of microbial community compositions and structures of CWWTPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Isolation of Sulfur Reducing and Oxidizing Bacteria Found in Contaminated Drywall

Directory of Open Access Journals (Sweden)

Frederick T. Guilford

2010-02-01

Full Text Available Drywall from China has been reported to release sulfur producing products which are corrosive to metals, result in noxious odors, and represent a significant health risk. It has been reported that these emissions produce medical symptoms such as respiratory or asthma type problems, sinusitis, gastrointestinal disorders, and vision problems in home owners and their household pets. We report here a method of identifying a causative agent for these emissions by sampling affected gypsum wallboard and subjecting those samples to Real Time Polymerase Chain Reaction [RT-PCR] studies. Specific DNA probes and primers have been designed and patented that detect a specific iron and sulfur reducing bacterium (i.e., Thiobacillus ferrooxidans. One hundred percent of affected drywall samples obtained from homes located in the southeastern United States tested positive for the presence of T. ferrooxidans. All negative controls consisting of unaffected wallboard and internal controls, Geotrichum sp., tested negative within our limits of detection.

Recent knowledge about the role of bacterial adhesion in coal preparation

Directory of Open Access Journals (Sweden)

Turèániová ¼udmila

1998-09-01

Full Text Available V nadväznosti na flotáciu pyritu v uhlí sú zhrnuté súèasné poznatky o vplyve fyzikálno-chemických vlastností buneènej steny baktérie Thiobacillus ferrooxidans na jej adhéziu na povrch rôznych minerálov a uhlia. Aplikovaním modelu mikrobiálnej adhézie (Škvarla, J. Chem. Soc. Faraday Trans., 89, 1993, p. 2913-2921 a využitím známych parametrov vstupujúcich do tohoto modelu bolo zistené, že k (reverzibilnej adhézii T. ferrooxidans dochádza spravidla v sekundárnom minime. Pre posúdenie možnosti využitia tohoto modelu na objasnenie selektívneho prichytenia T. ferrooxidans na pyrit je však potrebné doplni chýbajúce údaje vstupujúce do tohoto modelu.

THE BIOCATALYTIC DESULFURIZATION PROJECT

Energy Technology Data Exchange (ETDEWEB)

Steven E. Bonde; David Nunn

2003-01-01

During the first quarter of the Biological Desulfurization project several activities were pursued. A project kickoff meeting was held at the Diversa facility in San Diego, CA. Activities that were in process before the meeting and begun afterwards by Diversa Corporation and Petro Star Inc. include: Technology transfer in the form of information generated by Enchira to Diversa, the purchase and installation of equipment by Diversa, development of synthetic methods and preparation of organo-sulfur substrates for use in determining enzyme activities, production of extract via Petro Star's CED process, detailed analysis of Petro Star Inc. diesel and CED extract, and several activities in molecular biology. Diversa Corporation, in the area of molecular biology, engaged in several activities in support of the task list of the contract. These included: construction of a genomic library; development and utilization of a sequence-based gene discovery effort; a parallel discovery approach based on functional expression of enzymes with the ability to oxidize organosulfur compounds. Biodesulfurization genes have already been identified and are being sequenced and subcloned for expression in heterologous biological hosts. Diversa has evaluated and adapted assays developed by Enchira used to assess the activities of DBT and DBTO{sub 2} monooxygenases. Finally, Diversa personnel have developed two novel selection/screen strategies for the improvement of biocatalyst strains by directed evolution.

A physiologically based kinetic model for bacterial sulfide oxidation.

Science.gov (United States)

Klok, Johannes B M; de Graaff, Marco; van den Bosch, Pim L F; Boelee, Nadine C; Keesman, Karel J; Janssen, Albert J H

2013-02-01

In the biotechnological process for hydrogen sulfide removal from gas streams, a variety of oxidation products can be formed. Under natron-alkaline conditions, sulfide is oxidized by haloalkaliphilic sulfide oxidizing bacteria via flavocytochrome c oxidoreductase. From previous studies, it was concluded that the oxidation-reduction state of cytochrome c is a direct measure for the bacterial end-product formation. Given this physiological feature, incorporation of the oxidation state of cytochrome c in a mathematical model for the bacterial oxidation kinetics will yield a physiologically based model structure. This paper presents a physiologically based model, describing the dynamic formation of the various end-products in the biodesulfurization process. It consists of three elements: 1) Michaelis-Menten kinetics combined with 2) a cytochrome c driven mechanism describing 3) the rate determining enzymes of the respiratory system of haloalkaliphilic sulfide oxidizing bacteria. The proposed model is successfully validated against independent data obtained from biological respiration tests and bench scale gas-lift reactor experiments. The results demonstrate that the model is a powerful tool to describe product formation for haloalkaliphilic biomass under dynamic conditions. The model predicts a maximum S⁰ formation of about 98 mol%. A future challenge is the optimization of this bioprocess by improving the dissolved oxygen control strategy and reactor design. Copyright © 2012 Elsevier Ltd. All rights reserved.

Endogenous influences on anammox and sulfocompound-oxidizing autotrophic denitrification coupling system (A/SAD) and dynamic operating strategy.

Science.gov (United States)

Sun, Xinbo; Du, Lingfeng; Hou, Yuqian; Cheng, Shaoju; Zhang, Xuxiang; Liu, Bo

2018-02-21

The anaerobic ammonia oxidation (anammox) and sulfocompound-oxidizing autotrophic denitrification coupling system (A/SAD) was initiated in an expanded granular sludge bed (EGSB) reactor for nitrogen removal from high-strength wastewater. Owing to cooperation between anammox and partial sulfocompound-oxidation autotrophic denitrification coupling system (PSAD), the highest nitrogen removal efficiency (NRE) of 98.1% ± 0.4% achieved at the optimal influent conditions of conversion efficiency of ammonium (CEA) of 55% and S 2 O 3 2- -S/NO 3 - -N (S/N) of 1.4 mol mol -1 . The activity of the short-cut sulfocompound-oxidizing autotrophic denitrification (SSAD) was also regulated to cope with dynamic CEA in the influent by changing the S/N, which was demonstrated to be effective in alleviating nitrite accumulation when the CEA was between 57% and 61%. Both the anammox and SAD bacteria enriched in the reactor after long-term incubation. Candidatus Brocadia and Candidatus Jettenia might be potentially contributing the most to anammox, while the Thiobacillus was the dominant taxa related to SAD. Copyright © 2018. Published by Elsevier Ltd.

Exploring the Molecular Basis for Selective Binding of Homoserine Dehydrogenase from Mycobacterium leprae TN toward Inhibitors: A Virtual Screening Study

Directory of Open Access Journals (Sweden)

Dongling Zhan

2014-01-01

Full Text Available Homoserine dehydrogenase (HSD from Mycobacterium leprae TN is an antifungal target for antifungal properties including efficacy against the human pathogen. The 3D structure of HSD has been firmly established by homology modeling methods. Using the template, homoserine dehydrogenase from Thiobacillus denitrificans (PDB Id 3MTJ, a sequence identity of 40% was found and molecular dynamics simulation was used to optimize a reliable structure. The substrate and co-factor-binding regions in HSD were identified. In order to determine the important residues of the substrate (l-aspartate semialdehyde (l-ASA binding, the ASA was docked to the protein; Thr163, Asp198, and Glu192 may be important because they form a hydrogen bond with HSD through AutoDock 4.2 software. neuraminidaseAfter use of a virtual screening technique of HSD, the four top-scoring docking hits all seemed to cation–π ion pair with the key recognition residue Lys107, and Lys207. These ligands therefore seemed to be new chemotypes for HSD. Our results may be helpful for further experimental investigations.

Response of microbial communities to pesticide residues in soil restored with Azolla imbricata.

Science.gov (United States)

Lu, Xiao-Ming; Lu, Peng-Zhen

2018-01-01

Under conditions of Azolla imbricata restoration, the high-throughput sequencing technology was employed to determine change trends of microbial community structures in the soil that had undergone long-term application of pesticides. The relationship between the content of pesticide residues in the soil and the microbial community structure was analyzed. The results indicated that the microbial diversity was strongly negatively correlated with the contents of pesticide residues in the soil. At a suitable dosage of 5 kg fresh A. imbricata per square meter of soil area, the soil microbial diversity increased by 12.0%, and the contents of pesticide residues decreased by 26.8-72.1%. Sphingobacterium, Sphingopyxis, Thermincola, Sphingobium, Acaryochloris, Megasphaera, Ralstonia, Pseudobutyrivibrio, Desulfitobacterium, Nostoc, Oscillochloris, and Aciditerrimonas may play major roles in the degradation of pesticide residues. Thauera, Levilinea, Geothrix, Thiobacillus, Thioalkalispira, Desulfobulbus, Polycyclovorans, Fluviicola, Deferrisoma, Erysipelothrix, Desulfovibrio, Cytophaga, Vogesella, Zoogloea, Azovibrio, Halomonas, Paludibacter, Crocinitomix, Haliscomenobacter, Hirschia, Silanimonas, Alkalibacter, Woodsholea, Peredibacter, Leptolinea, Chitinivorax, Candidatus_Lumbricincola, Anaerovorax, Propionivibrio, Parasegetibacter, Byssovorax, Runella, Leptospira, and Nitrosomonas may be indicators to evaluate the contents of pesticide residues.

Structure of nitrogen-converting communities induced by hydraulic retention time and COD/N ratio in constantly aerated granular sludge reactors treating digester supernatant.

Science.gov (United States)

Cydzik-Kwiatkowska, Agnieszka; Rusanowska, Paulina; Zielińska, Magdalena; Bernat, Katarzyna; Wojnowska-Baryła, Irena

2014-02-01

This study investigated how hydraulic retention time (HRT) and COD/N ratio affect nitrogen-converting consortia in constantly aerated granules treating high-ammonium digester supernatant. Three HRTs (10, 13, 19 h) were tested at COD/N ratios of 4.5 and 2.3. Denaturing gradient gel electrophoresis and relative real-time PCR were used to characterize the microbial communities. When changes in HRT and COD/N increased nitrogen loading, the ratio of the relative abundance of aerobic to anaerobic ammonium-oxidizers decreased. The COD/N ratio determined the species composition of the denitrifiers; however, Thiobacillus denitrificans, Pseudomonas denitrificans and Azoarcus sp. showed a high tolerance to the environmental conditions and occurred in the granules from all reactors. Denitrifier genera that support granule formation were identified, such as Pseudomonas, Shinella, and Flavobacterium. In aerated granules, nirK-possessing bacteria were more diverse than nirS-possessing bacteria. At a low COD/N ratio, N2O-reducer diversity increased because of the presence of bacteria known as aerobic denitrifiers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Identification of the autotrophic denitrifying community in nitrate removal reactors by DNA-stable isotope probing.

Science.gov (United States)

Xing, Wei; Li, Jinlong; Cong, Yuan; Gao, Wei; Jia, Zhongjun; Li, Desheng

2017-04-01

Autotrophic denitrification has attracted increasing attention for wastewater with insufficient organic carbon sources. Nevertheless, in situ identification of autotrophic denitrifying communities in reactors remains challenging. Here, a process combining micro-electrolysis and autotrophic denitrification with high nitrate removal efficiency was presented. Two batch reactors were fed organic-free nitrate influent, with H 13 CO 3 - and H 12 CO 3 - as inorganic carbon sources. DNA-based stable-isotope probing (DNA-SIP) was used to obtain molecular evidence for autotrophic denitrifying communities. The results showed that the nirS gene was strongly labeled by H 13 CO 3 - , demonstrating that the inorganic carbon source was assimilated by autotrophic denitrifiers. High-throughput sequencing and clone library analysis identified Thiobacillus-like bacteria as the most dominant autotrophic denitrifiers. However, 88% of nirS genes cloned from the 13 C-labeled "heavy" DNA fraction showed low similarity with all culturable denitrifiers. These findings provided functional and taxonomical identification of autotrophic denitrifying communities, facilitating application of autotrophic denitrification process for wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial nitrate removal in biologically enhanced treated coal gasification wastewater of low COD to nitrate ratio by coupling biological denitrification with iron and carbon micro-electrolysis.

Science.gov (United States)

Zhang, Zhengwen; Han, Yuxing; Xu, Chunyan; Ma, Wencheng; Han, Hongjun; Zheng, Mengqi; Zhu, Hao; Ma, Weiwei

2018-04-21

Mixotrophic denitrification coupled biological denitrification with iron and carbon micro-electrolysis (IC-ME) is a promising emerging bioprocess for nitrate removal of biologically enhanced treated coal gasification wastewater (BECGW) with low COD to nitrate ratio. TN removal efficiency in R1 with IC-ME assisted was 16.64% higher than R2 with scrap zero valent iron addition, 23.05% higher than R3 with active carbon assisted, 30.51% higher than R4 with only active sludge addition, 80.85% higher than R5 utilizing single IC-ME as control. Fe 2+ generated from IC-ME decreased the production of N 2 O and enriched more Nitrate-reducing Fe(Ⅱ) oxidation bacteria (NRFOB) Acidovorax and Thiobacillus, which could convert nitrate to nitrogen gas. And the presence of Fe 3+ , as the Fe 2+ oxidation product, could stimulate the growth of Fe(III)-reducing strain (FRB) that indicated by redundancy analysis. Microbial network analysis demonstrated FRB Geothrix had a co-occurrence relationship with other bacteria, revealing its dominant involvement in nitrate removal of BECGW. Copyright © 2018 Elsevier Ltd. All rights reserved.

Micro-electrolysis/retinervus luffae-based simultaneous autotrophic and heterotrophic denitrification for low C/N wastewater treatment.

Science.gov (United States)

Li, Jinlong; Li, Desheng; Cui, Yuwei; Xing, Wei; Deng, Shihai

2017-07-01

Nitrogen bioremediation in organic insufficient wastewater generally requires an extra carbon source. In this study, nitrate-contaminated wastewater was treated effectively through simultaneous autotrophic and heterotrophic denitrification based on micro-electrolysis carriers (MECs) and retinervus luffae fructus (RLF), respectively. The average nitrate and total nitrogen removal rates reached 96.3 and 94.0% in the MECs/RLF-based autotrophic and heterotrophic denitrification (MRAHD) system without ammonia and nitrite accumulation. The performance of MRAHD was better than that of MEC-based autotrophic denitrification for the wastewater treatment with low carbon nitrogen (COD/N) ratio. Real-time quantitative polymerase chain reaction (qPCR) revealed that the relative abundance of nirS-type denitrifiers attached to MECs (4.9%) and RLF (5.0%) was similar. Illumina sequencing suggested that the dominant genera were Thiobacillus (7.0%) and Denitratisoma (5.7%), which attached to MECs and RLF, respectively. Sulfuritalea was discovered as the dominant genus in the middle of the reactor. The synergistic interaction between autotrophic and heterotrophic denitrifiers played a vital role in the mixotrophic substrate environment.

Studies of detailed biofilm characterization on fly ash concrete in comparison with normal and superplasticizer concrete in seawater environments.

Science.gov (United States)

Vishwakarmaa, Vinita; George, R P; Ramachandran, D; Anandkumar, B; Mudalib, U Kamachi

2014-01-01

In cooling water systems, many concrete structures in the form of tanks, pillars and reservoirs that come in contact with aggressive seawater are being deteriorated by chemical and biological factors. The nuclear industry has decided to partially replace the Portland cement with appropriate pozzolans such as fly ash, which could densify the matrix and make the concrete impermeable. Three types of concrete mixes, viz., normal concrete (NC), concrete with fly ash and superplasticizer (FA) and concrete with only superplasticizer (SP) were fabricated for short- and long-term exposure studies and for screening out the better concrete in seawater environments. Biofilm characterization studies and microscopic studies showed excellent performance of FA concrete compared to the other two. Laboratory exposure studies in pure cultures of Thiobacillus thiooxidans and Fusarium oxysporum were demonstrated for the inhibition of microbial growth on fly ash. Epifluorescence and scanning electron microscopic studies supported the better performance of the FA specimen. Thus, the present study clearly showed that FA concrete is less prone to biofilm formation and biodeterioration.

Microbially influenced degradation of cement-solidified low-level radioactive waste forms

International Nuclear Information System (INIS)

Rogers, R.D.; Hamilton, M.A.; Veeh, R.H.; McConnell, J.W. Jr.

1996-01-01

Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. This paper contains information on three groups of microoganisms that are associated with the degradation of cement materials: sulfur-oxidizing bacteria (Thiobacillus), nitrifying bacteria (Nitrosomonas and Nitrobacter), and heterotrophic bacteria, which produce organic acids. Preliminary work using laboratory- and vendor-manufactured, simulated waste forms exposed to thiobacilli has shown that microbiologically influenced degradation has the potential to severely compromise the structural integrity of ion-exchange resin and evaporator-bottoms waste that is solidified with cement. In addition, it was found that a significant percentage of calcium was leached from the treated waste forms. Also, the surface pH of the treated specimens was decreased to below 2. These conditions apparently contributed to the physical deterioration of simulated waste forms after 30 to 60 days of exposure

Biodesulfurization of Naphthothiophene and Benzothiophene through Selective Cleavage of Carbon-Sulfur Bonds by Rhodococcus sp. Strain WU-K2R

Science.gov (United States)

Kirimura, Kohtaro; Furuya, Toshiki; Sato, Rika; Ishii, Yoshitaka; Kino, Kuniki; Usami, Shoji

2002-01-01

Naphtho[2,1-b]thiophene (NTH) is an asymmetric structural isomer of dibenzothiophene (DBT), and in addition to DBT derivatives, NTH derivatives can also be detected in diesel oil following hydrodesulfurization treatment. Rhodococcus sp. strain WU-K2R was newly isolated from soil for its ability to grow in a medium with NTH as the sole source of sulfur, and growing cells of WU-K2R degraded 0.27 mM NTH within 7 days. WU-K2R could also grow in the medium with NTH sulfone, benzothiophene (BTH), 3-methyl-BTH, or 5-methyl-BTH as the sole source of sulfur but could not utilize DBT, DBT sulfone, or 4,6-dimethyl-DBT. On the other hand, WU-K2R did not utilize NTH or BTH as the sole source of carbon. By gas chromatography-mass spectrometry analysis, desulfurized NTH metabolites were identified as NTH sulfone, 2′-hydroxynaphthylethene, and naphtho[2,1-b]furan. Moreover, since desulfurized BTH metabolites were identified as BTH sulfone, benzo[c][1,2]oxathiin S-oxide, benzo[c][1,2]oxathiin S,S-dioxide, o-hydroxystyrene, 2-(2′-hydroxyphenyl)ethan-1-al, and benzofuran, it was concluded that WU-K2R desulfurized NTH and BTH through the sulfur-specific degradation pathways with the selective cleavage of carbon-sulfur bonds. Therefore, Rhodococcus sp. strain WU-K2R, which could preferentially desulfurize asymmetric heterocyclic sulfur compounds such as NTH and BTH through the sulfur-specific degradation pathways, is a unique desulfurizing biocatalyst showing properties different from those of DBT-desulfurizing bacteria. PMID:12147483

Evidence of biogenic corrosion of titanium after exposure to a continuous culture of thiobacillus ferrooxidans grown in thiosulfate medium

International Nuclear Information System (INIS)

Horn, J M; Martin, S I; Masterson, B

2000-01-01

Experiments were undertaken to evaluate extreme conditions under which candidate materials intended for use in a proposed nuclear waste repository might be susceptible to corrosion by endogenous microorganisms. Thiobucillus ferrooxidans, a sulfur-oxidizing bacterium, was grown in continuous culture using thiosulfate as an energy source; thiosulfate is oxidized to sulfate as a metabolic endproduct by this organism. Culture conditions were optimized to produce a high-density, metabolically active culture throughout a period of long term incubation in the presence of Alloy 22 (a high nickel-based alloy) and Titanium grade 7 (Tigr7) material coupons. After seven months incubation under these conditions, material coupons were withdrawn and analyzed by high resolution microscopy and energy dispersive x-ray analyses. Alloy 22 coupons showed no detectable signs of corrosion. Tigr7, however, demonstrated distinct roughening of the coupon surface, and [presumably solubilized and precipitated] titanium was detected on Alloy 22 coupons incubated in the same T. ferrooxiduns culture vessel. Control coupons of these materials incubated in sterile thiosulfate medium did not demonstrate any signs of corrosion, thus showing that observed corrosive effects were due to the T. ferrooxidans metabolic activities. T. ferrooxidans intermediates of thiosulfate oxidation or sulfate may have caused the corrosive effects observed on Tigr7

Report on Japan/Republic of Kazakhstan cooperative research project (March, 1996)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Joint technological development was conducted with the purpose of increasing operational efficiency of metal mines (refining of lead, copper, etc.) in Kazakhstan. This paper explains the fiscal 1995 results. Ores and tailings were sampled from three mines, with wastewater sampled from drainage ponds of one plant. The characteristics and conditions of coexistence of various minerals were studied mineralogically, determining the grades of valuable minerals, identifying and analyzing ore minerals. A hydrometallurgical processing was applied to a preliminary test for the purpose of enhancing research efficiency by separating and concentrating effective substances in the mineral samples as much as possible. Performed as leaching tests were a mechanical stirring method (for fine particles), column method (for coarse particles), bacterial method, chalcopyrite method (for tailing), etc.. In the stirring method, about 80% of copper was recovered. In the tailing concentration by the Fe{sup 3+} chalcopyrite method, the quantity and temperature of Fe{sup 3+} as an oxidizing agent affected the rate of concentration of copper. The bacteria leaching test using the sample from the drainage pond revealed existence of Thiobacillus ferrooxidus bacteria that was effective for leaching. (NEDO)

Microbial interspecies electron transfer via electric currents through conductive minerals

Science.gov (United States)

Kato, Souichiro; Hashimoto, Kazuhito; Watanabe, Kazuya

2012-01-01

In anaerobic biota, reducing equivalents (electrons) are transferred between different species of microbes [interspecies electron transfer (IET)], establishing the basis of cooperative behaviors and community functions. IET mechanisms described so far are based on diffusion of redox chemical species and/or direct contact in cell aggregates. Here, we show another possibility that IET also occurs via electric currents through natural conductive minerals. Our investigation revealed that electrically conductive magnetite nanoparticles facilitated IET from Geobacter sulfurreducens to Thiobacillus denitrificans, accomplishing acetate oxidation coupled to nitrate reduction. This two-species cooperative catabolism also occurred, albeit one order of magnitude slower, in the presence of Fe ions that worked as diffusive redox species. Semiconductive and insulating iron-oxide nanoparticles did not accelerate the cooperative catabolism. Our results suggest that microbes use conductive mineral particles as conduits of electrons, resulting in efficient IET and cooperative catabolism. Furthermore, such natural mineral conduits are considered to provide ecological advantages for users, because their investments in IET can be reduced. Given that conductive minerals are ubiquitously and abundantly present in nature, electric interactions between microbes and conductive minerals may contribute greatly to the coupling of biogeochemical reactions. PMID:22665802

A Comparative Study on the Effect of Flotation Reagents on Growth and Iron Oxidation Activities of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans

Directory of Open Access Journals (Sweden)

Mohammad Jafari

2016-12-01

Full Text Available Recently, extraction of metals from different resources using a simple, efficient, and low-cost technique-known as bioleaching-has been widely considered, and has turned out to be an important global technology. Leptospirillum ferrooxidans and Acidithiobacillus (Thiobacillus ferrooxidans are ubiquitous bacteria in the biomining industry. To date, the effects of commercial flotation reagents on the biooxidation activities of these bacteria have not been thoroughly studied. This investigation, by using various systematic measurement methods, studied the effects of various collectors and frothers (collectors: potassium amylxanthate, potassium isobutyl-xanthate, sodium ethylxanthate, potassium isopropylxanthate, and dithiophosphate; and frothers: pine oil and methyl isobutyl carbinol on L. ferrooxidans and A. ferrooxidans activities. In general, results indicate that in the presence of these collectors and frothers, L. ferrooxidans is less sensitive than T. ferrooxidans. In addition, the inhibition effect of collectors on both bacteria is recommended in the following order: for the collectors, potassium isobutyl-xanthate > dithiophosphate > sodium ethylxanthate > potassium isobutyl-xanthate > potassium amylxanthate; and for the frothers, methyl isobutyl carbinol > pine oil. These results can be used for the optimization of biometallurgical processes or in the early stage of a process design for selection of flotation reagents.

FY 2000 report on the results of the research and development project for utilization of information of high-molecular-weight structures in a living body. Survey on the technological trends of utilizing the reactions with metals in a living body; 2000 nendo seitai kobunshi kozo joho riyo gijutsu kaihatsu chosa hokokusho. 'Seitai kinzoku hanno riyo gijutsu' ni kansuru gijutsu doko chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Described herein are the FY 2000 results of the survey on the technological trends of utilizing the reactions with metals in a living body, noting the bio-processes effectively coping with the environmental problems. The effects of heavy metals on microorganisms have been investigated on the molecular biology level, but are not fully elucidated. Recently, the microorganisms capable of converting inorganic metal ions in water into the insoluble compounds have been known, leading to possibility of bioremediation to solve pollution by heavy metals, which have detrimental effects on human health. Heavy metals must be recovered, because they are not extinct by decomposition. The plant aided purification has been attracting attention to cope with heavy metals accumulated in soil. Application of bacteria-aided leaching, which is adopted as one ore smelting process, to the technologies for utilizing metals in a living body has been expected, because diversified activities of inanimate matters in extreme environments have been known. Recently, bio-machining of metals aided by Thiobacillus ferrooxidans, one species of independent nutrient bacteria capable of eating metals, has been developed to a potentially viable stage. (NEDO)

Compared microbiology of granular sludge under autotrophic, mixotrophic and heterotrophic denitrification conditions.

Science.gov (United States)

Fernández, N; Sierra-Alvarez, R; Amils, R; Field, J A; Sanz, J L

2009-01-01

Water contamination by nitrate is a wideworld extended phenomena. Biological autotrophic denitrification has a real potential to face this problem and presents less drawbacks than the most extended heterotrophic denitrification. Three bench-scale UASB reactors were operated under autotrophic (R1, H2S as electron donor), mixotrophic (R2, H2S plus p-cresol as electron donors) and heterotrophic (R3, p-cresol as electron donor) conditions using nitrate as terminal electron acceptor. 16S rDNA genetic libraries were built up to compare their microbial biodiversity. Six different bacteria phyla and three archaeal classes were observed. Proteobacteria was the main phyla in all reactors standing out the presence of denitrifiers. Microorganisms similar to Thiobacillus denitrificans and Acidovorax sp. performed the autotrophic denitification. These OTUs were displaced by chemoheterotrophic denitrifiers, especially by Limnobacter-like and Ottowia-like OTUs. Other phyla were Bacteroidetes, Chloroflexi, Firmicutes and Actinobacteria that--as well as Archaea members--were implicated in the degradation of organic matter, as substrate added as coming from endogenous sludge decay under autotrophic conditions. Archaea diversity remained low in all the reactors being Methanosaeta concilii the most abundant one.

Limnobacter thiooxidans gen. nov., sp. nov., a novel thiosulfate-oxidizing bacterium isolated from freshwater lake sediment.

Science.gov (United States)

Spring, S; Kämpfer, P; Schleifer, K H

2001-07-01

Two novel thiosulfate-oxidizing strains were isolated from sediment of the littoral zone of a freshwater lake (Lake Chiemsee, Bavaria, Germany). The new isolates, designated CS-K1 and CS-K2T, were gram-negative, slightly curved rods with pointed ends that were motile by means of single polar flagella. Both strains were obligately aerobic and grew on a variety of organic substrates, but not autotrophically. The utilization of thiosulfate led to an increase in the growth yield, indicating that these strains were able to grow chemolithoheterotrophically by oxidation of thiosulfate to sulfate. The optimum thiosulfate concentrations for growth were determined to be 10 mM for strain CS-K1 and 20 mM for strain CS-K2T. Phylogenetically, both strains were affiliated to the beta-Proteobacteria. Their characterization by a polyphasic approach resulted in the placement of both strains into a single species that is related only distantly to any known type species. Thus, the creation of a novel taxon is proposed, with the name Limnobacter thiooxidans gen. nov., sp. nov., to include the novel strains. In addition, the phylogenetic position of the chemolithoheterotrophic strain 'Thiobacillus' Q was determined.

FY 2000 report on the results of the research and development project for utilization of information of high-molecular-weight structures in a living body. Survey on the technological trends of utilizing the reactions with metals in a living body; 2000 nendo seitai kobunshi kozo joho riyo gijutsu kaihatsu chosa hokokusho. 'Seitai kinzoku hanno riyo gijutsu' ni kansuru gijutsu doko chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Described herein are the FY 2000 results of the survey on the technological trends of utilizing the reactions with metals in a living body, noting the bio-processes effectively coping with the environmental problems. The effects of heavy metals on microorganisms have been investigated on the molecular biology level, but are not fully elucidated. Recently, the microorganisms capable of converting inorganic metal ions in water into the insoluble compounds have been known, leading to possibility of bioremediation to solve pollution by heavy metals, which have detrimental effects on human health. Heavy metals must be recovered, because they are not extinct by decomposition. The plant aided purification has been attracting attention to cope with heavy metals accumulated in soil. Application of bacteria-aided leaching, which is adopted as one ore smelting process, to the technologies for utilizing metals in a living body has been expected, because diversified activities of inanimate matters in extreme environments have been known. Recently, bio-machining of metals aided by Thiobacillus ferrooxidans, one species of independent nutrient bacteria capable of eating metals, has been developed to a potentially viable stage. (NEDO)

UJI KUALITATIF DAN KUANTITATIF EKSTRAK Sargassum sp. DAN Gracilaria sp. SEBAGAI INHIBITOR BIO-KOROSI PADA BAJA KARBON

Directory of Open Access Journals (Sweden)

Isriyanti Affifah

2016-07-01

Full Text Available Korosi atau perkaratan logam merupakan proses oksidasi suatu logam dengan udara atau elektrolit. Udara atau elektrolit tersebut akan mengalami reduksi, sehingga proses korosi merupakan proses elektrokimia. Pada penelitian sebelumnya diketahui bahwa korosi yang disebabkan mikroorganisme pengoksidasi besi (Thiobacillus ferooxidans memiliki peranan yang cukup signifikan terhadap kerugian ekonomi bagi industri. Lapisan biofilm yang dihasilkan mikroorganisme pada permukaan logam dapat mengubah karakteristik elektrokimia permukaan logam tersebut dan dapat menginduksi terjadinya korosi. Untuk mengatasi masalah tersebut, pada penelitian ini dilakukan ekstraksi Sargassum sp. dan Gracilaria sp. yang diduga efektif menginhibisi pertumbuhan mikroba pengoksidasi besi (Thibacillus ferooxidans yang biasanya terdapat di bangunan bawah laut. Hasil ekstraksi Sargassum sp. dan Gracilaria sp. menggunakan pelarut metanol-kloroform (1:1 memberikan yield terhadap berat basah sebesar 44,5% dan 36,5%. Ekstrak tersebut diuji bioaktivitasnya terhadap pertumbuhan T. ferooxidans secara kualitatif (kasat mata dan kuantitatif (metode weight-loss. Melalui kurva pertumbuhan diketahui bahwa T. ferooxidans mampu tumbuh sampai hari ke-7 dan mengalami fasa stasioner pada hari ke-8. Analisis metode weight-loss dilakukan menggunakan coupon dengan luas permukaan 3,6 cm2. Hasil analisis menunjukkan bahwa ekstrak Gracilaria sp mampu menginhibisi 29,3% lebih efektif daripada biocide komersial.

FY 1995 report on the cooperative research on the development of environmentally friendly high efficiency mineral resource extraction/treatment technology; 1995 nendo kankyo chowagata kokoritsu kobutsu shigen chushutsu shori gijutsu no kaihatsu ni kansuru kenkyu kyoryoku hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

This promotion project on the cooperative research aims to efficiently extract and recover valuable metals (gold, silver, copper, rare metal, etc.) including in large quantity in tailings of ores in the Republic of Kazakhstan. In FY 1995, conducted were the field survey, support study in Japan, acceptance of researchers from Kazakhstan, conceptual design of pilot plant, etc. The ore/mineral for Cu is mainly an alteration ore of chalcopyrite. Au and Ag are low grade and unknown, and the main gangue mineral is pyrite. The low grade ore (waste/much) of the Nikolayevska mine has a tendency to leaching at normal temperature, but the ore of mostly chalcopyrite such as tailings from each place has difficulty in leaching. It gets leaching by increasing temperature. The more the temperature rises, the more conspicuous the reaction becomes. Further, chalcopyrite is leached with priority over pyrite. From the result, a technical potentiality was obtained of leaching of low grade chalcopyrite in tailings mostly of pyrite. The existence of Thiobacillus ferrooxidans was confirmed. As to the recovery method for Au and Ag, CIC is studied. The process of waste/much is solvent extraction, electrowinning study and leaching, and that of tailings is bacteria leaching and leaching study. (NEDO)

From lithotroph- to organotroph-dominant: directional shift of microbial community in sulphidic tailings during phytostabilization

Science.gov (United States)

Li, Xiaofang; Bond, Philip L.; Van Nostrand, Joy D.; Zhou, Jizhong; Huang, Longbin

2015-01-01

Engineering microbial diversity to enhance soil functions may improve the success of direct revegetation in sulphidic mine tailings. Therefore, it is essential to explore how remediation and initial plant establishment can alter microbial communities, and, which edaphic factors control these changes under field conditions. A long-term revegetation trial was established at a Pb-Zn-Cu tailings impoundment in northwest Queensland. The control and amended and/or revegetated treatments were sampled from the 3-year-old trial. In total, 24 samples were examined using pyrosequencing of 16S rRNA genes and various chemical properties. The results showed that the microbial diversity was positively controlled by soil soluble Si and negatively controlled by soluble S, total Fe and total As, implying that pyrite weathering posed a substantial stress on microbial development in the tailings. All treatments were dominated by typical extremophiles and lithotrophs, typically Truepera, Thiobacillus, Rubrobacter; significant increases in microbial diversity, biomass and frequency of organotrophic genera (typically Nocardioides and Altererythrobacter) were detected in the revegetated and amended treatment. We concluded that appropriate phytostabilization options have the potential to drive the microbial diversity and community structure in the tailings toward those of natural soils, however, inherent environmental stressors may limit such changes. PMID:26268667

Report on assessment of the mechanism of bacterially assisted oxidation of pyritic uranium tailings

International Nuclear Information System (INIS)

Halbert, B.B.; Scharer, J.M.; Knapp, R.A.

1984-07-01

The oxidation of pyritic minerals has been shown to be catalyzed by the presence of iron- and sulphur-oxidizing bacteria. Thiobacillus ferroxidans plays the most significant role in the formation and propagation of acidic conditions. Optimum growth conditions for the T. ferroxidans occurs at a temperature of 35 degrees C and pH of 2 to 3. Bacterially assisted oxidation of pyrite involves both direct and indirect contact mechanisms. The direct contact mechanism entails enzymatic oxidation of the insoluble sulphide moiety. The indirect mechanism involves bacterial oxidation of the dissolved ferrous component to the ferric state. The ferric iron, in turn, acts as the prime oxidant of pyrite and is reduced to ferrous iron. The re-oxidation of the dissolved ferrous component which is catalyzed by bacterial activity, completes the cyclic process. The rate of bacterial oxidation is affected by: the geochemistry and reactivity of the pyritic material; the amount of pyrite present in the waste material and the exposed surface area of the pyritic component; the availability of oxygen and carbon dioxide; the pH and temperature of the leach solution; and the presence (or absence) of organic inhibitors. Of the above factors, oxygen has been frequently identified as the rate limiting reactant in tailings

Thermophilic prokaryotic communities inhabiting the biofilm and well water of a thermal karst system located in Budapest (Hungary).

Science.gov (United States)

Anda, Dóra; Makk, Judit; Krett, Gergely; Jurecska, Laura; Márialigeti, Károly; Mádl-Szőnyi, Judit; Borsodi, Andrea K

2015-07-01

In this study, scanning electron microscopy (SEM) and 16S rRNA gene-based phylogenetic approach were applied to reveal the morphological structure and genetic diversity of thermophilic prokaryotic communities of a thermal karst well located in Budapest (Hungary). Bacterial and archaeal diversity of the well water (73.7 °C) and the biofilm developed on the inner surface of an outflow pipeline of the well were studied by molecular cloning method. According to the SEM images calcium carbonate minerals serve as a surface for colonization of bacterial aggregates. The vast majority of the bacterial and archaeal clones showed the highest sequence similarities to chemolithoautotrophic species. The bacterial clone libraries were dominated by sulfur oxidizer Thiobacillus (Betaproteobacteria) in the water and Sulfurihydrogenibium (Aquificae) in the biofilm. A relatively high proportion of molecular clones represented genera Thermus and Bellilinea in the biofilm library. The most abundant phylotypes both in water and biofilm archaeal clone libraries were closely related to thermophilic ammonia oxidizer Nitrosocaldus and Nitrososphaera but phylotypes belonging to methanogens were also detected. The results show that in addition to the bacterial sulfur and hydrogen oxidation, mainly archaeal ammonia oxidation may play a decisive role in the studied thermal karst system.

Characterization of the bacterial community in a biotrickling filter treating high loads of H(2)S by molecular biology tools.

Science.gov (United States)

Maestre, Juan P; Rovira, Roger; Gamisans, Xavier; Kinney, Kerry A; Kirisits, Mary Jo; Lafuente, Javier; Gabriel, David

2009-01-01

The diversity and spatial distribution of bacteria in a lab-scale biotrickling filter treating high loads of hydrogen sulfide (H(2)S) were investigated. Diversity and community structure were studied by terminal-restriction fragment length polymorphism (T-RFLP). A 16S rRNA gene clone library was established. Near Full-length 16S rRNA gene sequences were obtained, and clones were clustered into 24 operational taxonomic units (OTUs). Nearly 74% and 26% of the clones were affiliated with the phyla Proteobacteria and Bacteroidetes, respectively. Beta-, epsilon- and gamma-proteobacteria accounted for 15, 9 and 48%, respectively. Around 45% of the sequences retrieved were affiliated to bacteria of the sulfur cycle including Thiothrix spp., Thiobacillus spp. and Sulfurimonas denitrificans. Sequences related to Thiothrix lacustris accounted for a 38%. Rarefaction curve demonstrated that clone library constructed can be sufficient to describe the vast majority of the bacterial diversity of this reactor operating under strict conditions (2,000 ppm(v) of H(2)S). A spatial distribution of bacteria was found along the length of the reactor by means of the T-RFLP technique. Although aerobic species were predominant along the reactor, facultative anaerobes had a major relative abundance in the inlet part of the reactor, where the sulfide to oxygen ratio is higher.

Bacterial community composition characterization of a lead-contaminated Microcoleus sp. consortium.

Science.gov (United States)

Giloteaux, Ludovic; Solé, Antoni; Esteve, Isabel; Duran, Robert

2011-08-01

A Microcoleus sp. consortium, obtained from the Ebro delta microbial mat, was maintained under different conditions including uncontaminated, lead-contaminated, and acidic conditions. Terminal restriction fragment length polymorphism and 16S rRNA gene library analyses were performed in order to determine the effect of lead and culture conditions on the Microcoleus sp. consortium. The bacterial composition inside the consortium revealed low diversity and the presence of specific terminal-restriction fragments under lead conditions. 16S rRNA gene library analyses showed that members of the consortium were affiliated to the Alpha, Beta, and Gammaproteobacteria and Cyanobacteria. Sequences closely related to Achromobacter spp., Alcaligenes faecalis, and Thiobacillus species were exclusively found under lead conditions while sequences related to Geitlerinema sp., a cyanobacterium belonging to the Oscillatoriales, were not found in presence of lead. This result showed a strong lead selection of the bacterial members present in the Microcoleus sp. consortium. Several of the 16S rRNA sequences were affiliated to nitrogen-fixing microorganisms including members of the Rhizobiaceae and the Sphingomonadaceae. Additionally, confocal laser scanning microscopy and scanning and transmission electron microscopy showed that under lead-contaminated condition Microcoleus sp. cells were grouped and the number of electrodense intracytoplasmic inclusions was increased.

Utilisation of Food and Woodworking Production By-products by Composting

Directory of Open Access Journals (Sweden)

Uldis Viesturs

2004-10-01

Full Text Available The purpose of the study was to develop laboratory-scale technologies for composting milk/cheese whey, spent liquor, brewery yeast, fish processing by-products, etc., adding these by-products and special microorganism associations to the basic material - sawdust, bark, etc., also arranging different experimental composting sites. Two Trichoderma strains (Tr. lignorum, Tr. viride and a nitrification association for regulating the circulation of nitrogen-ammonification and nitrification processes were applied. Monitoring of the composting quality was realised by microbiological and chemical analyses, and biotests for compost quality (toxicity assessment. For purifying the polluted air from the composting facilities, the biofiltration technique was realised in a modified SSF system. Biodegradation of ammonia was investigated in a two-stage system with the inert packing material - dolomite broken bricks, and hemoautotrophic microorganisms: DN-1 (Pseudomonas sp., DN-2 (Nitrosomonas sp., DN-3 (Nitrobacter sp. and DN-13 (Sarcina sp.. For hydrogen sulphide biodegradation, Thiobacillus thioparus-3 was immobilised on glass bricks as the carrier material. Biodegradation efficiency of hydrogen sulphide was 87%. Biodegradation of ammonia in the first step in the two-stage system reached 77%, degradation of the gas remaining in the second step was 75%. Compost's quality was similar to black soil - brown-coloured, with good soil odour and without toxic compounds.

An examination of sulfur polymer cement as a waste encapsulation agent

International Nuclear Information System (INIS)

McNew, E.B.

1995-01-01

Sulfur polymer cement (SPC) is a unique material having potential applications for hazardous and radioactive waste encapsulation. This material was originally developed by the US Bureau of Mines as an acid and chemical resistant construction cement and has since been applied in tie waste encapsulation field. The material is easily prepared from elemental sulfur and organic dienes. It is an easy to use low-viscosity thermoplastic, and has many favorable properties such as low porosity, high compressive strength, and resistance to chemical attack. The results of several invetigations on this material will be discussed, and include: (1) the chemical form and physical structure of the material, (2) the compressive strength of cylindrical test samples after gamma radiation testing, (3) the aqueous leaching behavior of lead, cerium, cesium, cobalt, and strontium from SPC-ash mixtures at room and elevated temperatures, (4) the casting compatibility of mixtures of SPC with different waste materials, (5) the ability of SPC to encapsulate elemental mercury contaminated soils, (6) laboratory and field studies of SPC biocorrosion by Thiobacillus bacteria, (7) small scale (10 kg) SPC-ash monolith casting studies, and (8) methods for the formulation of a grade of SPC more applicable to the encapsulation of aggregate waste materials

Bacterial diversity in the active stage of a bioremediation system for mineral oil hydrocarbon-contaminated soils.

Science.gov (United States)

Popp, Nicole; Schlömann, Michael; Mau, Margit

2006-11-01

Soils contaminated with mineral oil hydrocarbons are often cleaned in off-site bioremediation systems. In order to find out which bacteria are active during the degradation phase in such systems, the diversity of the active microflora in a degrading soil remediation system was investigated by small-subunit (SSU) rRNA analysis. Two sequential RNA extracts from one soil sample were generated by a procedure incorporating bead beating. Both extracts were analysed separately by generating individual SSU rDNA clone libraries from cDNA of the two extracts. The sequencing results showed moderate diversity. The two clone libraries were dominated by Gammaproteobacteria, especially Pseudomonas spp. Alphaproteobacteria and Betaproteobacteria were two other large groups in the clone libraries. Actinobacteria, Firmicutes, Bacteroidetes and Epsilonproteobacteria were detected in lower numbers. The obtained sequences were predominantly related to genera for which cultivated representatives have been described, but were often clustered together in the phylogenetic tree, and the sequences that were most similar were originally obtained from soils and not from pure cultures. Most of the dominant genera in the clone libraries, e.g. Pseudomonas, Acinetobacter, Sphingomonas, Acidovorax and Thiobacillus, had already been detected in (mineral oil hydrocarbon) contaminated environmental samples. The occurrence of the genera Zymomonas and Rhodoferax was novel in mineral oil hydrocarbon-contaminated soil.

Bioreactor microbial ecosystems for thiocyanate and cyanide degradation unravelled with genome-resolved metagenomics.

Science.gov (United States)

Kantor, Rose S; van Zyl, A Wynand; van Hille, Robert P; Thomas, Brian C; Harrison, Susan T L; Banfield, Jillian F

2015-12-01

Gold ore processing uses cyanide (CN(-) ), which often results in large volumes of thiocyanate- (SCN(-) ) contaminated wastewater requiring treatment. Microbial communities can degrade SCN(-) and CN(-) , but little is known about their membership and metabolic potential. Microbial-based remediation strategies will benefit from an ecological understanding of organisms involved in the breakdown of SCN(-) and CN(-) into sulfur, carbon and nitrogen compounds. We performed metagenomic analysis of samples from two laboratory-scale bioreactors used to study SCN(-) and CN(-) degradation. Community analysis revealed the dominance of Thiobacillus spp., whose genomes harbour a previously unreported operon for SCN(-) degradation. Genome-based metabolic predictions suggest that a large portion of each bioreactor community is autotrophic, relying not on molasses in reactor feed but using energy gained from oxidation of sulfur compounds produced during SCN(-) degradation. Heterotrophs, including a bacterium from a previously uncharacterized phylum, compose a smaller portion of the reactor community. Predation by phage and eukaryotes is predicted to affect community dynamics. Genes for ammonium oxidation and denitrification were detected, indicating the potential for nitrogen removal, as required for complete remediation of wastewater. These findings suggest optimization strategies for reactor design, such as improved aerobic/anaerobic partitioning and elimination of organic carbon from reactor feed. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Biotechnical leaching of lean ores using heterotrophic microorganisms

International Nuclear Information System (INIS)

Schwartz, W.; Naeveke, R.

1980-01-01

After reporting briefly on leaching with Thiobacillus, it is discussed whether in those cases where thiobacilli fail to work the limits of microbial leaching are reached or still other groups of microorganisms will be suitable. In this relation the great number of carbon-heterotrophic fungi and bacteria have to be considered which are partly oligotrophic and occur e.g. in weathering biotopes of rocks and minerals and which may even include heavy metals in the dissolving processes of weathering. The active agents are, as far as is known up to now, organic acids which are produced by microorganisms and given off to the medium where they may combine with metals to form water-soluble complex compounds. In order to detect and isolate suitable strains of fungi and bacteria it will be necessary to work out a screening program which proceeds from general to special selections. Experiments to identify the active agents and the conditions of their production will have to follow. It remains still an open question whether such studies will result in technical processes. Mass production processes which are possible with the carbon-autotrophic and acidophilic thiobacilli are less probable than special processes to get hold of rare and economically valuable metals whose extraction would be difficult by other means. (orig.) [de

The geomicrobiology of bauxite deposits

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Xiluo Hao

2010-10-01

Full Text Available Bauxite deposits are studied because of their economic value and because they play an important role in the study of paleoclimate and paleogeography of continents. They provide a rare record of the weathering and evolution of continental surfaces. Geomicrobiological analysis makes it possible to verify that microorganisms have played a critical role during the formation of bauxite with the possibility already intimated in previous studies. Ambient temperature, abundance of water, organic carbon and bioavailable iron and other metal substrates provide a suitable environment for microbes to inhabit. Thiobacillus, Leptospirilum, Thermophilic bacteria and Heterotrophs have been shown to be able to oxidize ferrous iron and to reduce sulfate-generating sulfuric acid, which can accelerate the weathering of aluminosilicates and precipitation of iron oxyhydroxides. Microorganisms referred to the genus Bacillus can mediate the release of alkaline metals. Although the dissimilatory iron-reducing and sulfate-reducing bacteria in bauxites have not yet been identified, some recorded authigenic carbonates and “bacteriopyrites” that appear to be unique in morphology and grain size might record microbial activity. Typical bauxite minerals such as gibbsite, kaolinite, covellite, galena, pyrite, zircon, calcium plagioclase, orthoclase, and albite have been investigated as part of an analysis of microbial mediation. The paleoecology of such bauxitic microorganisms inhabiting continental (sub surfaces, revealed through geomicrobiological analysis, will add a further dimension to paleoclimatic and paleoenvironmental studies.

Simultaneous bioreduction of nitrate and chromate using sulfur-based mixotrophic denitrification process

Energy Technology Data Exchange (ETDEWEB)

Sahinkaya, Erkan, E-mail: erkansahinkaya@yahoo.com [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey); Kilic, Adem [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey); Calimlioglu, Beste; Toker, Yasemin [Istanbul Medeniyet University, Bioengineering Department, Goztepe, Istanbul (Turkey)

2013-11-15

Highlights: • Simultaneous heterotrophic and autotrophic denitrification was stimulated. • Simultaneous bioreduction of nitrate and chromate was achieved. • Total chromium decreased <50 μg/L when the influent Cr(VI) was ≤5 mg/L. -- Abstract: This study aims at evaluating simultaneous chromate and nitrate reduction using sulfur-based mixotrophic denitrification process in a column reactor packed with elemental sulfur and activated carbon. The reactor was supplemented with methanol at C/N ratio of 1.33 or 2. Almost complete denitrification was achieved at influent NO{sub 3}{sup −}–N and Cr(VI) concentrations of 75 mg/L and 10 mg/L, respectively, and 3.7 h HRT. Maximum denitrification rate was 0.5 g NO{sub 3}{sup −}–N/(L.d) when the bioreactor was fed with 75 mg/L NO{sub 3}{sup −}–N, 150 mg/L methanol and 10 mg/L Cr(VI). The share of autotrophic denitrification was between 12% and 50% depending on HRT, C/N ratio and Cr(VI) concentration. Effluent total chromium was below 50 μg/L provided that influent Cr(VI) concentration was equal or below 5 mg/L. DGGE results showed stable microbial community throughout the operation and the presence of sulfur oxidizing denitrifying bacteria (Thiobacillus denitrificans) and Cr(VI) reducing bacteria (Exiguobacterium spp.) in the column bed.

Polyphasic bacterial community analysis of an aerobic activated sludge removing phenols and thiocyanate from coke plant effluent

Energy Technology Data Exchange (ETDEWEB)

Felfoldi, T.; Szekely, A.J.; Goral, R.; Barkacs, K.; Scheirich, G.; Andras, J.; Racz, A.; Marialigeti, K. [Eotvos Lorand University, Budapest (Hungary). Dept. of Microbiology

2010-05-15

Biological purification processes are effective tools in the treatment of hazardous wastes such as toxic compounds produced in coal coking. In this study, the microbial community of a lab-scale activated sludge system treating coking effluent was assessed by cultivation-based (strain isolation and identification, biodegradation tests) and culture-independent techniques (sequence-aided T-RFLP, taxon-specific PCR). The results of the applied polyphasic approach showed a simple microbial community dominated by easily culturable heterotrophic bacteria. Comamonas badia was identified as the key microbe of the system, since it was the predominant member of the bacterial community, and its phenol degradation capacity was also proved. Metabolism of phenol, even at elevated concentrations (up to 1500 mg/L), was also presented for many other dominant (Pseudomonas, Rhodanobacter, Oligella) and minor (Alcaligenes, Castellaniella, Microbacterium) groups, while some activated sludge bacteria (Sphingomonas, Rhodopseudomonas) did not tolerate it even in lower concentrations (250 mg/L). In some cases, closely related strains showed different tolerance and degradation properties. Members of the genus Thiobacillus were detected in the activated sludge, and were supposedly responsible for the intensive thiocyanate biodegradation observed in the system. Additionally, some identified bacteria (e.g. C. badia and the Ottowia-related strains) might also have had a significant impact on the structure of the activated sludge due to their floc-forming abilities.

Distribution and Diversity of Bacteria and Fungi Colonization in Stone Monuments Analyzed by High-Throughput Sequencing.

Science.gov (United States)

Li, Qiang; Zhang, Bingjian; He, Zhang; Yang, Xiaoru

The historical and cultural heritage of Qingxing palace and Lingyin and Kaihua temple, located in Hangzhou of China, include a large number of exquisite Buddhist statues and ancient stone sculptures which date back to the Northern Song (960-1219 A.D.) and Qing dynasties (1636-1912 A.D.) and are considered to be some of the best examples of ancient stone sculpting techniques. They were added to the World Heritage List in 2011 because of their unique craftsmanship and importance to the study of ancient Chinese Buddhist culture. However, biodeterioration of the surface of the ancient Buddhist statues and white marble pillars not only severely impairs their aesthetic value but also alters their material structure and thermo-hygric properties. In this study, high-throughput sequencing was utilized to identify the microbial communities colonizing the stone monuments. The diversity and distribution of the microbial communities in six samples collected from three different environmental conditions with signs of deterioration were analyzed by means of bioinformatics software and diversity indices. In addition, the impact of environmental factors, including temperature, light intensity, air humidity, and the concentration of NO2 and SO2, on the microbial communities' diversity and distribution was evaluated. The results indicate that the presence of predominantly phototrophic microorganisms was correlated with light and humidity, while nitrifying bacteria and Thiobacillus were associated with NO2 and SO2 from air pollution.

Biotransformation of nitrogen- and sulfur-containing pollutants during coking wastewater treatment: Correspondence of performance to microbial community functional structure.

Science.gov (United States)

Joshi, Dev Raj; Zhang, Yu; Gao, Yinxin; Liu, Yuan; Yang, Min

2017-09-15

Although coking wastewater is generally considered to contain high concentration of nitrogen- and sulfur-containing pollutants, the biotransformation processes of these compounds have not been well understood. Herein, a high throughput functional gene array (GeoChip 5.0) in combination with Illumina MiSeq sequencing of the 16S rRNA gene were used to identify microbial functional traits and their role in biotransformation of nitrogen- and sulfur-containing compounds in a bench-scale aerobic coking wastewater treatment system operated for 488 days. Biotransformation of nitrogen and sulfur-containing pollutants deteriorated when pH of the bioreactor was increased to >8.0, and the microbial community functional structure was significantly associated with pH (Mantels test, P functional microbial community structure (P functional genes for biotransformation of nitrogen- and sulfur-containing pollutants. Functional characterization of taxa and network analysis suggested that Burkholderiales, Actinomycetales, Rhizobiales, Pseudomonadales, and Hydrogenophiliales (Thiobacillus) were key functional taxa. Variance partitioning analysis showed that pH and influent ammonia nitrogen jointly explained 25.9% and 35.5% of variation in organic pollutant degrading genes and microbial community structure, respectively. This study revealed a linkage between microbial community functional structure and the likely biotransformation of nitrogen- and sulfur-containing pollutants, along with a suitable range of pH (7.0-7.5) for stability of the biological system treating coking wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial leaching of low grade sandstone uranium ores: column leaching studies

International Nuclear Information System (INIS)

Bhatti, T.M.; Malik, K.A.; Khalid, A.M.

1991-01-01

Microbial leaching studies on a low-grade sandstone uranium ore from Baghalchur Ore Deposits, D. G. Khan, Pakistan, containing 0.027 % U/sub 3/O/sub 8/ for extraction of uranium, were conducted in columns. Baghalchur sandstone uranium ore which is alkaline in nature, contained 5.0% calcite [CaCo/sub 3/], 2-3 % Fe/sub 2/O/sub 3/ and pyrite [FeS/sub 2/] less than 0.1 %. The ore amended with sulfur and/or sulfur slag as external energy source was found to leach with indigenous microflora mostly belonging to the genus Thiobacillus which are present in the uranium mine water. Column leaching studies revealed that when the ore was amended with elemental sulfur and irrigated with mine water (pH 3.5) 53 % U/sub 3/O/sub 8/ could be solubilized from it. However, when the natural mine water was used as such (pH 7.4) the solubilization of uranium was decreased to 41 % U/sub 3/O/sub 8/ in 90 days under similar conditions of percolation rate and temperature. The addition of (NH/sub 4/)/sub 2/SO/sub 4/ (3.0 g/L) in mine water was found to enhance the uranium leaching to 70 % U/sub 3/O/sub 8/ from the columns containing ore amended with sulfur slag. (author)

The Oxidative Metabolism of Fossil Hydrocarbons and Sulfide Minerals by the Lithobiontic Microbial Community Inhabiting Deep Subterrestrial Kupferschiefer Black Shale

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Agnieszka Włodarczyk

2018-05-01

Full Text Available Black shales are one of the largest reservoirs of fossil organic carbon and inorganic reduced sulfur on Earth. It is assumed that microorganisms play an important role in the transformations of these sedimentary rocks and contribute to the return of organic carbon and inorganic sulfur to the global geochemical cycles. An outcrop of deep subterrestrial ~256-million-year-old Kupferschiefer black shale was studied to define the metabolic processes of the deep biosphere important in transformations of organic carbon and inorganic reduced sulfur compounds. This outcrop was created during mining activity 12 years ago and since then it has been exposed to the activity of oxygen and microorganisms. The microbial processes were described based on metagenome and metaproteome studies as well as on the geochemistry of the rock. The microorganisms inhabiting the subterrestrial black shale were dominated by bacterial genera such as Pseudomonas, Limnobacter, Yonghaparkia, Thiobacillus, Bradyrhizobium, and Sulfuricaulis. This study on black shale was the first to detect archaea and fungi, represented by Nitrososphaera and Aspergillus genera, respectively. The enzymatic oxidation of fossil aliphatic and aromatic hydrocarbons was mediated mostly by chemoorganotrophic bacteria, but also by archaea and fungi. The dissimilative enzymatic oxidation of primary reduced sulfur compounds was performed by chemolithotrophic bacteria. The geochemical consequences of microbial activity were the oxidation and dehydrogenation of kerogen, as well as oxidation of sulfide minerals.

Using biological and physico-chemical test methods to assess the role of concrete mixture design in resistance to microbially induced corrosion

Science.gov (United States)

House, Mitchell Wayne

Concrete is the most widely used material for construction of wastewater collection, storage, and treatment infrastructure. The chemical and physical characteristics of hydrated portland cement make it susceptible to degradation under highly acidic conditions. As a result, some concrete wastewater infrastructure may be susceptible to a multi-stage degradation process known as microbially induced corrosion, or MIC. MIC begins with the production of aqueous hydrogen sulfide (H2S(aq)) by anaerobic sulfate reducing bacteria present below the waterline. H2S(aq) partitions to the gas phase where it is oxidized to sulfuric acid by the aerobic sulfur oxidizing bacteria Thiobacillus that resides on concrete surfaces above the waterline. Sulfuric acid then attacks the cement paste portion of the concrete matrix through decalcification of calcium hydroxide and calcium silica hydrate coupled with the formation of expansive corrosion products. The attack proceeds inward resulting in reduced service life and potential failure of the concrete structure. There are several challenges associated with assessing a concrete's susceptibility to MIC. First, no standard laboratory tests exist to assess concrete resistance to MIC. Straightforward reproduction of MIC in the laboratory is complicated by the use of microorganisms and hydrogen sulfide gas. Physico-chemical tests simulating MIC by immersing concrete specimens in sulfuric acid offer a convenient alternative, but do not accurately capture the damage mechanisms associated with biological corrosion. Comparison of results between research studies is difficult due to discrepancies that can arise in experimental methods even if current ASTM standards are followed. This thesis presents two experimental methods to evaluate concrete resistance to MIC: one biological and one physico-chemical. Efforts are made to address the critical aspects of each testing method currently absent in the literature. The first method presented is a new test

Effect of light on Thiobacilli

International Nuclear Information System (INIS)

Le Roux, N.W.; Marshall, V.M.

1977-01-01

The aim was to study the effect of visible and ultra-violet light on some members of the genus Thiobacillus. This genus is one more example of an aerobic organism which undergoes what appears to be the widespread phenomenon of light inhibition. Light inhibition of thiobacilli has been observed before and these other observations are presented. In the present study the effect of both visible and U-V light on three species was considered, viz. T. thiooxidans, T. thioparus and T. ferrooxidans, the latter species being studied more thoroughly with respect to different intensities and wavelengths of light and the shielding effect of bacterial numbers and ferric iron. The photoreactivation of T. ferrooxidans cells after irradiation by U-V light was also examined. Using unfiltered, visible light, there was an inhibitory effect on all three of the thiobacilli irrespective of the source being used. When selected wavelengths were studied it was seen that the blue end of the visible spectrum was most inhibitory. A relationship between ferric iron concentration and protection from visible light was shown and the beneficial protective effect of particulate suspensions was demonstrated. The sensitivity of T. ferrooxidans and T. thioparus to U-V light and the protection afforded by ferric iron and cell numbers was assessed. Photoreactivation of U-V irradiated cells by exposure to visible light showed that this phenomenon occurred using wavelengths of visible light which, by themselves, were inhibitory. Some practical implication of these findings are offered. (orig.) [de

Microbial community in high arsenic shallow groundwater aquifers in Hetao Basin of Inner Mongolia, China.

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Ping Li

Full Text Available A survey was carried out on the microbial community of 20 groundwater samples (4 low and 16 high arsenic groundwater and 19 sediments from three boreholes (two high arsenic and one low arsenic boreholes in a high arsenic groundwater system located in Hetao Basin, Inner Mongolia, using the 454 pyrosequencing approach. A total of 233,704 sequence reads were obtained and classified into 12-267 operational taxonomic units (OTUs. Groundwater and sediment samples were divided into low and high arsenic groups based on measured geochemical parameters and microbial communities, by hierarchical clustering and principal coordinates analysis. Richness and diversity of the microbial communities in high arsenic sediments are higher than those in high arsenic groundwater. Microbial community structure was significantly different either between low and high arsenic samples or between groundwater and sediments. Acinetobacter, Pseudomonas, Psychrobacter and Alishewanella were the top four genera in high arsenic groundwater, while Thiobacillus, Pseudomonas, Hydrogenophaga, Enterobacteriaceae, Sulfuricurvum and Arthrobacter dominated high arsenic sediments. Archaeal sequences in high arsenic groundwater were mostly related to methanogens. Biota-environment matching and co-inertia analyses showed that arsenic, total organic carbon, SO4(2-, SO4(2-/total sulfur ratio, and Fe(2+ were important environmental factors shaping the observed microbial communities. The results of this study expand our current understanding of microbial ecology in high arsenic groundwater aquifers and emphasize the potential importance of microbes in arsenic transformation in the Hetao Basin, Inner Mongolia.

Microbial community in high arsenic shallow groundwater aquifers in Hetao Basin of Inner Mongolia, China.

Science.gov (United States)

Li, Ping; Wang, Yanhong; Dai, Xinyue; Zhang, Rui; Jiang, Zhou; Jiang, Dawei; Wang, Shang; Jiang, Hongchen; Wang, Yanxin; Dong, Hailiang

2015-01-01

A survey was carried out on the microbial community of 20 groundwater samples (4 low and 16 high arsenic groundwater) and 19 sediments from three boreholes (two high arsenic and one low arsenic boreholes) in a high arsenic groundwater system located in Hetao Basin, Inner Mongolia, using the 454 pyrosequencing approach. A total of 233,704 sequence reads were obtained and classified into 12-267 operational taxonomic units (OTUs). Groundwater and sediment samples were divided into low and high arsenic groups based on measured geochemical parameters and microbial communities, by hierarchical clustering and principal coordinates analysis. Richness and diversity of the microbial communities in high arsenic sediments are higher than those in high arsenic groundwater. Microbial community structure was significantly different either between low and high arsenic samples or between groundwater and sediments. Acinetobacter, Pseudomonas, Psychrobacter and Alishewanella were the top four genera in high arsenic groundwater, while Thiobacillus, Pseudomonas, Hydrogenophaga, Enterobacteriaceae, Sulfuricurvum and Arthrobacter dominated high arsenic sediments. Archaeal sequences in high arsenic groundwater were mostly related to methanogens. Biota-environment matching and co-inertia analyses showed that arsenic, total organic carbon, SO4(2-), SO4(2-)/total sulfur ratio, and Fe(2+) were important environmental factors shaping the observed microbial communities. The results of this study expand our current understanding of microbial ecology in high arsenic groundwater aquifers and emphasize the potential importance of microbes in arsenic transformation in the Hetao Basin, Inner Mongolia.

Microbiological desulfurization and conversion of coal

International Nuclear Information System (INIS)

Quigley, D.R.; Stoner, D.L.; Dugan, P.R.

1991-01-01

Bio processing of coal is a young and emerging technology. Until the early 1980's it consisted primarily of coal depyritization using Thiobacillus ferro oxidans to either oxidize pyritic sulfur or to alter particle wettability or floatation properties by binding to exposed pyrite inclusions. Since then, other major avenues of research have been pursued. One of these is the microbiologically mediated liquefaction of coal. Initial work indicated that microorganisms were able to transform low rank coal into a black liquid that was later identified as water solubilized by alkaline substances produced by the microbes and could be enhanced by the removal of multi valent cations from coal. Current work at the INEL involves of the identification and characterization of microorganisms that are able to alter the structure of polymeric desulfurization of coal. This work initially focused on the ability of microorganisms to oxidatively remove organic sulfur from model compounds that were representative of those sulfur containing moieties identified as being in coals (e.g., dibenzo thiophene). The work also focused on those organisms that were could remove the organic sulfur without degrading the carbon structure. While some organisms that are able to perform such these reactions will effectively remove organo sulfur from coal. These concerns stem from steric hindrance considerations and the thermodynamically unfavourable nature of reaction. Current work at the INEL involves the isolation and biochemical characterization of microorganisms that are able to desulfurize and solubilized coals that have high organic sulfur contents. (author)

Distribution and Diversity of Bacteria and Fungi Colonization in Stone Monuments Analyzed by High-Throughput Sequencing.

Directory of Open Access Journals (Sweden)

Qiang Li

Full Text Available The historical and cultural heritage of Qingxing palace and Lingyin and Kaihua temple, located in Hangzhou of China, include a large number of exquisite Buddhist statues and ancient stone sculptures which date back to the Northern Song (960-1219 A.D. and Qing dynasties (1636-1912 A.D. and are considered to be some of the best examples of ancient stone sculpting techniques. They were added to the World Heritage List in 2011 because of their unique craftsmanship and importance to the study of ancient Chinese Buddhist culture. However, biodeterioration of the surface of the ancient Buddhist statues and white marble pillars not only severely impairs their aesthetic value but also alters their material structure and thermo-hygric properties. In this study, high-throughput sequencing was utilized to identify the microbial communities colonizing the stone monuments. The diversity and distribution of the microbial communities in six samples collected from three different environmental conditions with signs of deterioration were analyzed by means of bioinformatics software and diversity indices. In addition, the impact of environmental factors, including temperature, light intensity, air humidity, and the concentration of NO2 and SO2, on the microbial communities' diversity and distribution was evaluated. The results indicate that the presence of predominantly phototrophic microorganisms was correlated with light and humidity, while nitrifying bacteria and Thiobacillus were associated with NO2 and SO2 from air pollution.

The role of heterotrophic microorganism Galactomyces sp. Z3 in improving pig slurry bioleaching.

Science.gov (United States)

Zhou, Jun; Zheng, Guanyu; Zhou, Lixiang; Liu, Fenwu; Zheng, Chaocheng; Cui, Chunhong

2013-01-01

The feasibility of removing heavy metals and eliminating pathogens from pig slurry through bioleaching involving the fungus Galactomyces sp. Z3 and two acidophilic thiobacillus (A. ferrooxidans LX5 and A. thiooxidans TS6) was investigated. It was found that the isolated pig slurry dissolved organic matter (DOM) degrader Z3 was identified as Galactomyces sp. Z3, which could grow well at pH 2.5-7 and degrade pig slurry DOM from 1973 to 942 mg/l within 48 h. During the successive multi-batch bioleaching systems, the co-inoculation of pig slurry degrader Galactomyces sp. Z3 and the two Acidithiobacillus species could improve pig slurry bioleaching efficiency compared to the single system without Galactomyces sp. Z3. The removal efficiency of Zn and Cu exceeded 94% and 85%, respectively. In addition, the elimination efficiencies of pathogens, including both total coliform and faecal coliform counts, exceeded 99% after bioleaching treatment. However, the counts of Galactomyces sp. Z3 decreased with the fall of pH and did not restore to the initial level during successive multi-batch bioleaching systems, and it is necessary to re-inoculate Galactomyces sp. Z3 cells into the bioleaching system to maintain its role in degrading pig slurry DOM. Therefore, a bioleaching technique involving both Galactomyces sp. Z3 and Acidithiobacillus species is an efficient method for removing heavy metals and eliminating pathogens from pig slurry.

Polyphasic analysis of an Azoarcus-Leptothrix-dominated bacterial biofilm developed on stainless steel surface in a gasoline-contaminated hypoxic groundwater.

Science.gov (United States)

Benedek, Tibor; Táncsics, András; Szabó, István; Farkas, Milán; Szoboszlay, Sándor; Fábián, Krisztina; Maróti, Gergely; Kriszt, Balázs

2016-05-01

Pump and treat systems are widely used for hydrocarbon-contaminated groundwater remediation. Although biofouling (formation of clogging biofilms on pump surfaces) is a common problem in these systems, scarce information is available regarding the phylogenetic and functional complexity of such biofilms. Extensive information about the taxa and species as well as metabolic potential of a bacterial biofilm developed on the stainless steel surface of a pump submerged in a gasoline-contaminated hypoxic groundwater is presented. Results shed light on a complex network of interconnected hydrocarbon-degrading chemoorganotrophic and chemolitotrophic bacteria. It was found that besides the well-known hydrocarbon-degrading aerobic/facultative anaerobic biofilm-forming organisms (e.g., Azoarcus, Leptothrix, Acidovorax, Thauera, Pseudomonas, etc.), representatives of Fe(2+)-and Mn(2+)-oxidizing (Thiobacillus, Sideroxydans, Gallionella, Rhodopseudomonas, etc.) as well as of Fe(3+)- and Mn(4+)-respiring (Rhodoferax, Geobacter, Magnetospirillum, Sulfurimonas, etc.) bacteria were present in the biofilm. The predominance of β-Proteobacteria within the biofilm bacterial community in phylogenetic and functional point of view was revealed. Investigation of meta-cleavage dioxygenase and benzylsuccinate synthase (bssA) genes indicated that within the biofilm, Azoarcus, Leptothrix, Zoogloea, and Thauera species are most probably involved in intrinsic biodegradation of aromatic hydrocarbons. Polyphasic analysis of the biofilm shed light on the fact that subsurface microbial accretions might be reservoirs of novel putatively hydrocarbon-degrading bacterial species. Moreover, clogging biofilms besides their detrimental effects might supplement the efficiency of pump and treat systems.

Effects of toxic organic flotation reagent (aniline aerofloat) on an A/O submerged membrane bioreactor (sMBR): Microbial community dynamics and performance.

Science.gov (United States)

Lin, Weixiong; Sun, Shuiyu; Wu, Chun; Xu, Pingting; Ye, Ziwei; Zhuang, Shengwei

2017-08-01

Bio-treatment of flotation wastewater has been proven to be both effective and economical, as a treatment method. Despite this, little is known regarding the effects of toxic organic floatation reagents such as Dianilinodithiophosphoric acid (DDA), on the microbial community performance or dynamics, which are critical to the effective performance of the bio-treatment reactor. A submerged membrane bioreactor (sMBR) was constructed to continuously treat simulated wastewater contaminated with DDA, an organic flotation reagent that is now considered a significant pollutant. The performance of the sMBR system was investigated at different DDA loading concentrations, with assessment of the effects of DDA on the microbial communities within the sMBR, in particular the biodiversity and succession within the microbial community. Results showed that, with increased DDA loadings, the performance of the sMBR was initially negatively affected, but the system adapted efficiently and consistently reached a COD removal rate of up to 80%. Increased DDA loading concentrations had an adverse effect on the activity of both the activated sludge and microbial communities, resulting in a large alteration in microbial dynamics, especially during the start-up stage and the high DDA loading stage. Strains capable of adapting to the presence of DDA, capable of degrading DDA or utilizing its byproducts, were enriched within the sMBR community, such as Zoogloea, Clostridium, Sideroxydans lithotrophicus, Thiobacillus, Thauera amino aromatica and Alicycliphilus denitrificans. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of methodology to evaluate microbially influenced degradation of cement-solidified low-level radioactive waste forms

International Nuclear Information System (INIS)

Rogers, R.D.; Hamilton, M.A.; Veeh, R.H.; McConnell, J.W.

1994-01-01

Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. An environmentally mediated process that could affect cement stability is the action of naturally occurring microorganisms. The US Nuclear Regulatory Commission (NRC), recognizing this eventuality, stated that the effects of microbial action on waste form integrity must be addressed. This paper provides present results from an ongoing program that addresses the effects of microbially influenced degradation (MID) on cement-solidified LLW. Data are provided on the development of an evaluation method using acid-producing bacteria. Results are from work with one type of these bacteria, the sulfur-oxidizing Thiobacillus. This work involved the use of a system in which laboratory- and vendor-manufactured, simulated waste forms were exposed on an intermittent basis to media containing thiobacilli. Testing demonstrated that MID has the potential to severely compromise the structural integrity of ion-exchange resin and evaporator-bottoms waste that is solidified with cement. In addition, it was found that a significant percentage of calcium and other elements were leached from the treated waste forms. Also, the surface pH of the treated specimens decreased to below 2. These conditions apparently contributed to the physical deterioration of simulated waste forms after 60 days of exposure to the thiobacilli

Conversion of sulfur compounds and microbial community in anaerobic treatment of fish and pork waste.

Science.gov (United States)

He, Ruo; Yao, Xing-Zhi; Chen, Min; Ma, Ruo-Chan; Li, Hua-Jun; Wang, Chen; Ding, Shen-Hua

2018-04-07

Volatile sulfur compounds (VSCs) are not only the main source of malodor in anaerobic treatment of organic waste, but also pose a threat to human health. In this study, VSCs production and microbial community was investigated during the anaerobic degradation of fish and pork waste. The results showed that after the operation of 245 days, 94.5% and 76.2% of sulfur compounds in the fish and pork waste was converted into VSCs. Among the detected VSCs including H 2 S, carbon disulfide, methanethiol, ethanethiol, dimethyl sulfide, dimethyl disulfide and dimethyl trisulfide, methanethiol was the major component with the maximum concentration of 4.54% and 3.28% in the fish and pork waste, respectively. The conversion of sulfur compounds including total sulfur, SO 4 2- -S, S 2- , methionine and cysteine followed the first-order kinetics. Miseq sequencing analysis showed that Acinetobacter, Clostridium, Proteus, Thiobacillus, Hyphomicrobium and Pseudomonas were the main known sulfur-metabolizing microorganisms in the fish and pork waste. The C/N value had most significant influence on the microbial community in the fish and pork waste. A main conversion of sulfur compounds with CH 3 SH as the key intermediate was firstly hypothesized during the anaerobic degradation of fish and pork waste. These findings are helpful to understand the conversion of sulfur compounds and to develop techniques to control ordor pollution in the anaerobic treatment of organic waste. Copyright © 2018. Published by Elsevier Ltd.

Sulfur source-mediated transcriptional regulation of the rhlABC genes involved in biosurfactants production by Pseudomonas sp. strain AK6U.

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Ismail, Wael; El Nayal, Ashraf M; Ramadan, Ahmed R; Abotalib, Nasser

2014-01-01

biodesulfurization.

Effects of the surfactant Tween 80 on the growth and dibenzothiophene utilization by Exophiala spinifera isolated from oil- contaminated soil

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Fatemeh Elmi

2016-06-01

Full Text Available Introduction: Oil is one of the most important energy sources that contain variety of organosulfur compounds that are combustible and can produce sulfur dioxide which will cause pollution over the atmosphere and the soil. Dibenzothiophene (DBT is often used as a model for biodesulfurization studies and surfactant Tween80 increases the solubility of DBT in water that leads to higher consumption by microorganisms. Materials and methods: DBT specific UV spectrophotometry at a wavelength of 323 nm was used to evaluate the ability of isolated Exophiala spinifera fungus in removal of DBT. The effect of various concentrations of surfactant Tween80 on the growth of the fungus and DBT utilization was studied. Results: Exophiala spinifera was able to remove 100% DBT after 7 days of incubation at 30 ° C and 180 rpm shaking. The effect of different concentrations of surfactant Tween80 on growth and DBT utilization by this fungus was examined and it was observed that the presence of surfactant in the culture medium increased the growth and removal of DBT, therefore the amount of DBT utilized with 0.4% concentration of the surfactant was about 30% more than that utilized without surfactant. However, higher concentrations of surfactant Tween80 decreased the growth and consumption of DBT by fungi. Discussion and conclusion: Exophiala spinifera was isolated from oil contaminated soil and able to utilize toxic compound DBT as a sulfur source in the presence of other carbon sources such as glucose. So this isolated strain could be a good candidate for the petroleum desulfurization and it is the first report about desulfurization of DBT by fungus Exophiala spinifera. Growth and removal of DBT by fungus increased in the presence of surfactant Tween80. It can be concluded that the surfactant increases the total DBT transfer between the organic and aqueous phases and has a potential application in DBT bioremediation system by the studied fungus biocatalyst.

Effects of nitrate on the stability of uranium in a bioreduced region of the subsurface

International Nuclear Information System (INIS)

Wu, Weimin; Carley, Jack M.; Green, Stefan; Luo, Jian; Kelly, Shelly D.; Van Nostrand, Joy; Lowe, Kenneth Alan; Mehlhorn, Tonia L.; Carroll, Sue L.; Boonchayanant, Benjaporn; Loeffler, Frank E.; Jardine, Philip M.; Criddle, Craig

2010-01-01

The effects of nitrate on the stability of reduced, immobilized uranium were evaluated in field experiments at a U.S. Department of Energy site in Oak Ridge, TN. Nitrate (2.0 mM) was injected into a reduced region of the subsurface containing high levels of previously immobilized U(IV). The nitrate was reduced to nitrite, ammonium, and nitrogen gas; sulfide levels decreased; and Fe(II) levels increased then deceased. Uranium remobilization occurred concomitant with nitrite formation, suggesting nitrate-dependent, iron-accelerated oxidation of U(IV). Bromide tracer results indicated changes in subsurface flowpaths likely due to gas formation and/or precipitate. Desorption-adsorption of uranium by the iron-rich sediment impacted uranium mobilization and sequestration. After rereduction of the subsurface through ethanol additions, background groundwater containing high levels of nitrate was allowed to enter the reduced test zone. Aqueous uranium concentrations increased then decreased. Clone library analyses of sediment samples revealed the presence of denitrifying bacteria that can oxidize elemental sulfur, H 2 S, Fe(II), and U(IV) (e.g., Thiobacillus spp.), and a decrease in relative abundance of bacteria that can reduce Fe(III) and sulfate. XANES analyses of sediment samples confirmed changes in uranium oxidation state. Addition of ethanol restored reduced conditions and triggered a short-term increase in Fe(II) and aqueous uranium, likely due to reductive dissolution of Fe(III) oxides and release of sorbed U(VI). After two months of intermittent ethanol addition, sulfide levels increased, and aqueous uranium concentrations gradually decreased to <0.1 μM.

A dynamic mathematical model for microbial removal of pyritic sulfur from coal.

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Kargi, F; Weissman, J G

1984-06-01

A dynamic mathematical model has been developed to describe microbial desulfurization of coal by Thiobacillus ferrooxidans. The model considers adsorption and desorption of cells on coal particles and microbial oxidation of pyritic sulfur on particle surfaces. The influence of certain parameters, such as microbial growth rate constants, adsorption-description constants, pulp density, coal particle size, initial cell and solid phase substrate concentration on the maximum rate of pyritic sulfur removal, have been elucidated. The maximum rate of pyritic sulfur removal was strongly dependent upon the number of attached cells per coal particle. At sufficiently high initial cell concentrations, the surfaces of coal particles are nearly saturated by the cells and the maximum leaching rate is limited either by total external surface area of coal particles or by the concentration of pyritic sulfur in the coal phase. The maximum volumetric rate of pyritic sulfur removal (mg S/h cm(3) mixture) increases with the pulp density of coal and reaches a saturation level at high pulp densities (e.g. 45%). The maximum rate also increases with decreasing particle diameter in a hyperbolic form. Increases in adsorption coefficient or decreases in the desorption coefficient also result in considerable improvements in this rate. The model can be applied to other systems consisting of suspended solid substrate particles in liquid medium with microbial oxidation occurring on the particle surfaces (e.g., bacterial ore leaching). The results obtained from this model are in good agreement with published experimental data on microbial desulfurization of coal and bacterial ore leaching.

GeoChip-based analysis of the microbial community functional structures in simultaneous desulfurization and denitrification process.

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Yu, Hao; Chen, Chuan; Ma, Jincai; Liu, Wenzong; Zhou, Jizhong; Lee, Duu-Jong; Ren, Nanqi; Wang, Aijie

2014-07-01

The elemental sulfur (S°) recovery was evaluated in the presence of nitrate in two development models of simultaneous desulfurization and denitrification (SDD) process. At the loading rates of 0.9 kg S/(m³·day) for sulfide and 0.4 kg N/(m³·day) for nitrate, S° conversion rate was 91.1% in denitrifying sulfide removal (DSR) model which was higher than in integrated simultaneous desulfurization and denitrification (ISDD) model (25.6%). A comprehensive analysis of functional diversity, structure and metabolic potential of microbial communities was examined in two models by using functional gene array (GeoChip 2.0). GeoChip data indicated that diversity indices, community structure, and abundance of functional genes were distinct between two models. Diversity indices (Simpson's diversity index (1/D) and Shannon-Weaver index (H')) of all detected genes showed that with elevated influent loading rate, the functional diversity decreased in ISDD model but increased in DSR model. In contrast to ISDD model, the overall abundance of dsr genes was lower in DSR model, while some functional genes targeting from nitrate-reducing sulfide-oxidizing bacteria (NR-SOB), such as Thiobacillus denitrificans, Sulfurimonas denitrificans, and Paracoccus pantotrophus were more abundant in DSR model which were highly associated with the change of S(0) conversion rate obtained in two models. The results obtained in this study provide additional insights into the microbial metabolic mechanisms involved in ISDD and DSR models, which in turn will improve the overall performance of SDD process. Copyright © 2014. Published by Elsevier B.V.

A Microbial Community in Sediments Beneath the Western Antarctic Ice Sheet, Ice Stream C (Kamb)

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Skidmore, M.; Han, S.; Foo, W.; Bui, D.; Lanoil, B.

2004-12-01

In 2000, an ice-drilling project focusing on the "sticky spot" of Ice Stream C recovered cores of sub-glacial sediments from beneath the Western Antarctic Ice Sheet. We have characterized several chemical and microbiological parameters of the sole intact sediment core. Pore waters extracted from these sediments were brackish and some were supersaturated with respect to calcite. Ion chromatography demonstrated the presence of several organic acids at low, but detectable, levels in the pore water. DAPI direct cell counts were approximately 107 cells g-1. Aerobic viable plate counts were much lower than direct cell counts; however, they were two orders of magnitude higher on plates incubated at low temperature (4 ° C; 3.63 x 105 CFU ml-1) than at higher temperatures (ca. 22° C; 1.5 x 103 CFU ml-1); no colonies were detected on plates incubated anaerobically at either temperature. 16S rDNA clone library analysis indicates extremely limited bacterial diversity in these samples: six phylogenetic clades were detected. The three dominant bacterial phylogenetic clades in the clone libraries (252 clones total) were most closely related to Thiobacillus thioparus (180 clones), Polaromonas vacuolata (34 clones), and Gallionella ferruginea (35 clones) and their relatives; one clone each represented the other three phylogenetic clades (most closely related to Ralstonia pickettii, Lysobacter antibioticus, and Xylella fastidiosa, respectively). These sequences match closely with sequences previously obtained from other subglacial environments in Alaska, Ellesmere Island, Canada and New Zealand. Implications of this microbial community to subglacial chemistry and microbial biogeography will be discussed.

Metagenome-scale analysis yields insights into the structure and function of microbial communities in a copper bioleaching heap.

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Zhang, Xian; Niu, Jiaojiao; Liang, Yili; Liu, Xueduan; Yin, Huaqun

2016-01-19

Metagenomics allows us to acquire the potential resources from both cultivatable and uncultivable microorganisms in the environment. Here, shotgun metagenome sequencing was used to investigate microbial communities from the surface layer of low grade copper tailings that were industrially bioleached at the Dexing Copper Mine, China. A bioinformatics analysis was further performed to elucidate structural and functional properties of the microbial communities in a copper bioleaching heap. Taxonomic analysis revealed unexpectedly high microbial biodiversity of this extremely acidic environment, as most sequences were phylogenetically assigned to Proteobacteria, while Euryarchaeota-related sequences occupied little proportion in this system, assuming that Archaea probably played little role in the bioleaching systems. At the genus level, the microbial community in mineral surface-layer was dominated by the sulfur- and iron-oxidizing acidophiles such as Acidithiobacillus-like populations, most of which were A. ferrivorans-like and A. ferrooxidans-like groups. In addition, Caudovirales were the dominant viral type observed in this extremely environment. Functional analysis illustrated that the principal participants related to the key metabolic pathways (carbon fixation, nitrogen metabolism, Fe(II) oxidation and sulfur metabolism) were mainly identified to be Acidithiobacillus-like, Thiobacillus-like and Leptospirillum-like microorganisms, indicating their vital roles. Also, microbial community harbored certain adaptive mechanisms (heavy metal resistance, low pH adaption, organic solvents tolerance and detoxification of hydroxyl radicals) as they performed their functions in the bioleaching system. Our study provides several valuable datasets for understanding the microbial community composition and function in the surface-layer of copper bioleaching heap.

Effects of Single and Combined Application of Organic and Biological Fertilizers on Quantitative and Qualitative Yield of Anisum (Pimpinella anisum

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N Kamayestani

2015-07-01

Full Text Available In order to study the effects of single and combined applications of biofertilazer and organic fertilizers on quantitative and qualitative characteristics of anisum (Pimpinella anisum, an experiment was conducted based on a Randomized Complete Block Design with three replications and fifteen treatments at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2011 year. Treatments were: (1 mycorrhiza (Glomus intraradices, (2 mycorrhiza + cow manure, (3 mycorrhiza + vermicompost, (4 mycorrhiza+ compost, (5 mycorrhiza + chemical fertilizer, (6 biosulfur (Thiobacillus sp. + Bentonite, (7 biosulfur + chemical fertilizer, (8 biosulfur + cow manure, (9 biosulfur + vermicompost, (10 biosulfur+compost,11 (cow manure, (12 vermicompost, (13 chemical fertilizer (NPK, (14compost and (15 control. The results showed that application of fertilizer treatments had significant effect on most characteristics of anisum. The highest number of seed per umbelet (7.24, economic yield (1263.4kg/ha were obtained fram biosulfur treatment. The highest dry matter yield (4504.1 kg/ha resulted from combined application of biosulfur + chemical fertilizer and the highest harvest index (25.97% observed in biosulfur+cow manure. The combined application of mycorrhiza affected some qualification traits, as the highest number of umbel per plant (65.7, 1000 seed-weight (3.24 g and essential oil percentage (5.3% resulted from combined application of mycorrhiza+chemical fertilizer. In general, it can be concluded that application of organic and biological fertilizer particularly mycorrhiza and biosulfur had a significant effect on improving of quantitative and qualitative characteristics of anisum. Furthermore, the combined application of organic and biological fertilizer had higher positive effects than their single application.

Response of soil microbial communities and microbial interactions to long-term heavy metal contamination.

Science.gov (United States)

Li, Xiaoqi; Meng, Delong; Li, Juan; Yin, Huaqun; Liu, Hongwei; Liu, Xueduan; Cheng, Cheng; Xiao, Yunhua; Liu, Zhenghua; Yan, Mingli

2017-12-01

Due to the persistence of metals in the ecosystem and their threat to all living organisms, effects of heavy metal on soil microbial communities were widely studied. However, little was known about the interactions among microorganisms in heavy metal-contaminated soils. In the present study, microbial communities in Non (CON), moderately (CL) and severely (CH) contaminated soils were investigated through high-throughput Illumina sequencing of 16s rRNA gene amplicons, and networks were constructed to show the interactions among microbes. Results showed that the microbial community composition was significantly, while the microbial diversity was not significantly affected by heavy metal contamination. Bacteria showed various response to heavy metals. Bacteria that positively correlated with Cd, e.g. Acidobacteria_Gp and Proteobacteria_thiobacillus, had more links between nodes and more positive interactions among microbes in CL- and CH-networks, while bacteria that negatively correlated with Cd, e.g. Longilinea, Gp2 and Gp4 had fewer network links and more negative interactions in CL and CH-networks. Unlike bacteria, members of the archaeal domain, i.e. phyla Crenarchaeota and Euryarchaeota, class Thermoprotei and order Thermoplasmatales showed only positive correlation with Cd and had more network interactions in CH-networks. The present study indicated that (i) the microbial community composition, as well as network interactions was shift to strengthen adaptability of microorganisms to heavy metal contamination, (ii) archaea were resistant to heavy metal contamination and may contribute to the adaption to heavy metals. It was proposed that the contribution might be achieved either by improving environment conditions or by cooperative interactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Structural characterization of the bacterial proteasome homolog BPH reveals a tetradecameric double-ring complex with unique inner cavity properties.

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Fuchs, Adrian C D; Maldoner, Lorena; Hipp, Katharina; Hartmann, Marcus D; Martin, Jörg

2018-01-19

Eukaryotic and archaeal proteasomes are paradigms for self-compartmentalizing proteases. To a large extent, their function requires interplay with hexameric ATPases associated with diverse cellular activities (AAA+) that act as substrate unfoldases. Bacteria have various types of self-compartmentalizing proteases; in addition to the proteasome itself, these include the proteasome homolog HslV, which functions together with the AAA+ HslU; the ClpP protease with its partner AAA+ ClpX; and Anbu, a recently characterized ancestral proteasome variant. Previous bioinformatic analysis has revealed a novel bacterial member of the proteasome family Betaproteobacteria proteasome homolog (BPH). Using cluster analysis, we here affirmed that BPH evolutionarily descends from HslV. Crystal structures of the Thiobacillus denitrificans and Cupriavidus metallidurans BPHs disclosed a homo-oligomeric double-ring architecture in which the active sites face the interior of the cylinder. Using small-angle X-ray scattering (SAXS) and electron microscopy averaging, we found that BPH forms tetradecamers in solution, unlike the dodecamers seen in HslV. Although the highly acidic inner surface of BPH was in striking contrast to the cavity characteristics of the proteasome and HslV, a classical proteasomal reaction mechanism could be inferred from the covalent binding of the proteasome-specific inhibitor epoxomicin to BPH. A ligand-bound structure implied that the elongated BPH inner pore loop may be involved in substrate recognition. The apparent lack of a partner unfoldase and other unique features, such as Ser replacing Thr as the catalytic residue in certain BPH subfamilies, suggest a proteolytic function for BPH distinct from those of known bacterial self-compartmentalizing proteases. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Denitrification of groundwater using a sulfur-oxidizing autotrophic denitrifying anaerobic fluidized-bed MBR: performance and bacterial community structure.

Science.gov (United States)

Zhang, Lili; Zhang, Chao; Hu, Chengzhi; Liu, Huijuan; Qu, Jiuhui

2015-03-01

This paper investigates a novel sulfur-oxidizing autotrophic denitrifying anaerobic fluidized bed membrane bioreactor (AnFB-MBR) that has the potential to overcome the limitations of conventional sulfur-oxidizing autotrophic denitrification systems. The AnFB-MBR produced consistent high-quality product water when fed by a synthetic groundwater with NO3 (-)-N ranging 25-80 mg/L and operated at hydraulic retention times of 0.5-5.0 h. A nitrate removal rate of up to 4.0 g NO3 (-)-N/Lreactord was attained by the bioreactor, which exceeded any reported removal capacity. The flux of AnFB-MBR was maintained in the range of 1.5-15 L m(-2) h(-1). Successful membrane cleaning was practiced with cleaning cycles of 35-81 days, which had no obvious effect on the AnFB-MBR performance. The (15) N-tracer analyses elucidated that nitrogen was converted into (15) N2-N and (15) N-biomass accounting for 88.1-93.1 % and 6.4-11.6 % of the total nitrogen produced, respectively. Only 0.3-0.5 % of removed nitrogen was in form of (15)N2O-N in sulfur-oxidizing autotrophic denitrification process, reducing potential risks of a significant amount of N2O emissions. The sulfur-oxidizing autotrophic denitrifying bacterial consortium was composed mainly of bacteria from Proteobacteria, Chlorobi, and Chloroflexi phyla, with genera Thiobacillus, Sulfurimonas, and Ignavibacteriales dominating the consortium. The pyrosequencing assays also suggested that the stable microbial communities corresponded to the elevated performance of the AnFB-MBR. Overall, this research described relatively high nitrate removal, acceptable flux, indicating future potential for the technology in practice.

EXAFS investigation of uranium(6) complexes formed at Acidithiobacillus ferro oxidans types

International Nuclear Information System (INIS)

Merroun, M.; Reich, T.; Hennig, Ch.; Selenska-Pobell, S.

2002-01-01

Mining activities have brought excessive amounts of uranium into the environment. In uranium deposits a number of acidophilic chemo-litho-autotrophic bacteria have been identified which are able to oxidize sulphide minerals, elemental sulphur, ferrous iron and also (in the presence of uranium mineral) U(IV). In particular, the interaction of one representative of the group Acidithiobacillus ferro oxidans (new designation of Thiobacillus ferro oxidans) with uranium has been investigated. Uranium(VI) complex formations at the surfaces of Acidithiobacillus ferro oxidans were studied using uranium L III -edge extended X-ray absorption fine structure (EXAFS) spectroscopy. In all samples uranium is co-ordinated by two axial oxygen atoms (O ax ) at a distance of 1.77-1.78 angstrom. The average distance between uranium and the equatorial oxygen atoms (O eq ) is 2.35 angstrom. The co-ordination number for O eq is 5-6. In comparison to the uranium crystal structure data, the U-O eq distance indicates a co-ordination number of the equatorial oxygen of 5. Within the experimental error, there are no differences in the U-O bond distances between samples from the three types of A. ferro oxidans investigated. The fit to the EXAFS data of samples measured as wet pastes gave the same results as for dried samples. No significant structural differences were observed for the uranium complexes formed by the eco-types of A. ferro oxidans. However, the EXAFS spectra do indicate a formation of uranium complexes which are different from those formed by Bacilli where the bond length of 2.28 angstrom indicates a co-ordination number of 4 for the equatorial oxygen atoms. (authors)

Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, September 11, 1992--December 11, 1992

Energy Technology Data Exchange (ETDEWEB)

Sublette, K.L.

1992-12-31

With the continual increase in the utilization of high sulfur and high nitrogen containing fossil fuels, the release of airborne pollutants into the environment has become a critical problem. The fuel sulfur is converted to SO{sub 2} during combustion. Fuel nitrogen and a fraction of the nitrogen from the combustion air are converted to nitric oxide and nitrogen dioxide, NO{sub x}. For the past five years Combustion Engineering (now Asea Brown Boveri or ABB) and, since 1986, the University of Tulsa (TU) have been investigating the oxidation of H{sub 2}S by the facultatively anaerobic and autotrophic bacterium Thiobacillus denitrificans and have developed a process, concept for the microbial removal of H{sub 2}S from a gas stream the simultaneous removal of SO{sub 2} and NO by D. desulfuricans and T. denitrificans co-cultures and cultures-in-series was demonstrated. These systems could not be sustained due to NO inhibition of D. desulfuricans. However, a preliminary economic analysis has shown that microbial reduction of SO{sub 2} to H{sub 2}S with subsequent conversion to elemental sulfur by the Claus process is both technically and economically feasible if a less expensive carbon and/or energy source can be found. It has also been demonstrated that T. denitrificans can be grown anaerobically on NO(g) as a terminal electron acceptor with reduction to elemental nitrogen. Microbial reduction of NO{sub x} is a viable process concept for the disposal of concentrated streams of NO{sub x} as may be produced by certain regenerable processes for the removal of SO{sub 2} and NO{sub x} from flue gas.

Some Soil Characters and Qualitative Traits of Sunflower Seeds to Different Nutritional Regimes

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F Soleymani

2018-05-01

Full Text Available Introduction To achieve the high economic yield in crops, supplying enough nutrients for plants is important, that much of it, supplied by chemical fertilizers. But excessive use of chemical fertilizers led to environmental problems that these negative effects have caused attention to healthy and ecological sustainable farming systems. One solution to reduce dependence on chemical fertilizers is application of organic and biological products for plant nutrition. Bio-fertilizers are made from one or more species of beneficial microorganisms with preservatives and or their products. In addition, vermicompost is an organic fertilizer and mixed of very active biological bacteria, enzymes, plant residues, manure and earthworm capsule which leads to continued organic matter decomposition and development of microbial and enzymatic activities in soil. Several experiments have shown that the using of biological and organic fertilizers improve growth and quality of products. Materials and Methods To investigate the effect of various nutritional regimes on seed quality characteristics of sunflower (Euroflour cv. and some soil characters, an experiment was carried out as a randomized complete block design with 3 replications in 2015 at the Agricultural Faculty of Bu-Ali Sina University.Treatments included no biological or chemical fertilizer application, 100% of the recommended NP fertilizers (250 kg urea per hectare, 50 kg triple superphosphate per hectare, ½ recomended NP fertilizers, vermicompost (15 ton per hectare mixed with soil, phosphonitrokara (including Bacillus coagulans, Azotobacter chroococcum, Azospirillum lipoferum, 110 ml to inoculate 10 kg seeds, biosulfur (including Thiobacillus,mix 6 kg of fertilizer with 300 kg sulphur for 1 hectare, vermicompost+ phosphonitrokara, vermicompost+ biosulfur, vermicompost+½ NP fertilizers, phosphonitrokara+½ NP fertilizers, biosulfur+½ NP fertilizers, vermicompost+ phosphonitrokara+½ NP fertilizers

Performance and microbial community composition in a long-term sequential anaerobic-aerobic bioreactor operation treating coking wastewater.

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Joshi, Dev Raj; Zhang, Yu; Tian, Zhe; Gao, Yingxin; Yang, Min

2016-09-01

The combined anaerobic-aerobic biosystem is assumed to consume less energy for the treatment of high strength industrial wastewater. In this study, pollutant removal performance and microbial diversity were assessed in a long-term (over 300 days) bench-scale sequential anaerobic-aerobic bioreactor treating coking wastewater. Anaerobic treatment removed one third of the chemical oxygen demand (COD) and more than half of the phenols with hydraulic retention time (HRT) of 42 h, while the combined system with total HRT of 114 h removed 81.8, 85.6, 99.9, 98.2, and 85.4 % of COD, total organic carbon (TOC), total phenols, thiocyanate, and cyanide, respectively. Two-dimensional gas chromatography with time-of-flight mass spectrometry showed complete removal of phenol derivatives and nitrogenous heterocyclic compounds (NHCs) via the combined system, with the anaerobic process alone contributing 58.4 and 58.6 % removal on average, respectively. Microbial activity in the bioreactors was examined by 454 pyrosequencing of the bacterial, archaeal, and fungal communities. Proteobacteria (61.2-93.4 %), particularly Betaproteobacteria (34.4-70.1 %), was the dominant bacterial group. Ottowia (14.1-46.7 %), Soehngenia (3.0-8.2 %), and Corynebacterium (0.9-12.0 %), which are comprised of phenol-degrading and hydrolytic bacteria, were the most abundant genera in the anaerobic sludge, whereas Thiobacillus (6.6-43.6 %), Diaphorobacter (5.1-13.0 %), and Comamonas (0.2-11.1 %) were the major degraders of phenol, thiocyanate, and NHCs in the aerobic sludge. Despite the low density of fungi, phenol degrading oleaginous yeast Trichosporon was abundant in the aerobic sludge. This study demonstrated the feasibility and optimization of less energy intensive treatment and the potential association between abundant bacterial groups and biodegradation of key pollutants in coking wastewater.

Integrated micro-biochemical approach for phytoremediation of cadmium and lead contaminated soils using Gladiolus grandiflorus L cut flower.

Science.gov (United States)

Mani, Dinesh; Kumar, Chitranjan; Patel, Niraj Kumar

2016-02-01

The potential of vermicompost, elemental sulphur, Thiobacillus thiooxidans and Pseudomonas putida for phytoremediation is well known individually but their integrated approach has not been discovered so far. The present work highlights the consideration of so far overlooked aspects of their integrated treatment by growing the ornamental plant, Gladiolus grandiflorus L in uncontaminated and sewage-contaminated soils (sulphur-deficient alluvial Entisols, pH 7.6-7.8) for phytoremediation of cadmium and lead under pot experiment. Between vermicompost and elemental sulphur, the response of vermicompost was higher towards improvement in the biometric parameters of plants, whereas the response of elemental sulphur was higher towards enhanced bioaccumulation of heavy metals under soils. The integrated treatment (T7: vermicompost 6g and elemental sulphur 0.5gkg(-1) soil and co-inoculation of the plant with T. thiooxidans and P. putida) was found superior in promoting root length, plant height and dry biomass of the plant. The treatment T7 caused enhanced accumulation of Cd up to 6.96 and 6.45mgkg(-1) and Pb up to 22.6 and 19.9mgkg(-1) in corm and shoot, respectively at the contaminated soil. T7 showed maximum remediation efficiency of 0.46% and 0.19% and bioaccumulation factor of 2.92 and 1.21 and uptake of 6.75 and 21.4mgkg(-1) dry biomass for Cd and Pb respectively in the contaminated soil. The integrated treatment T7 was found significant over the individual treatments to promote plant growth and enhance phytoremediation. Hence, authors conclude to integrate vermicompost, elemental sulphur and microbial co-inoculation for the enhanced clean-up of Cd and Pb-contaminated soils. Copyright © 2015 Elsevier Inc. All rights reserved.

Vegetation successfully prevents oxidization of sulfide minerals in mine tailings.

Science.gov (United States)

Li, Yang; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

2016-07-15

The oxidization of metal sulfide in tailings causes acid mine drainage. However, it remains unclear whether vegetation prevents the oxidization of metal sulfides. The oxidization characteristics and microbial indices of the tailings in the presence of various plant species were investigated to explore the effects of vegetation on the oxidization of sulfide minerals in tailings. The pH, reducing sulfur, free iron oxides (Fed), chemical oxygen consumption (COC) and biological oxygen consumption (BOC) were measured. Key iron- and sulfur-oxidizing bacteria (Acidithiobacillus spp., Leptospirillum spp. and Thiobacillus spp.) were quantified using real-time PCR. The results indicate that vegetation growing on tailings can effectively prevent the oxidization of sulfide minerals in tailings. A higher pH and reducing-sulfur content and lower Fed were observed in the 0-30 cm depth interval in the presence of vegetation compared to bare tailings (BT). The COC gradually decreased with depth in all of the soil profiles; specifically, the COC rapidly decreased in the 10-20 cm interval in the presence of vegetation but gradually decreased in the BT profiles. Imperata cylindrica (IC) and Chrysopogon zizanoides (CZ) profiles contained the highest BOC in the 10-20 cm interval. The abundance of key iron- and sulfur-oxidizing bacteria in the vegetated tailings were significantly lower than in the BT; in particular, IC was associated with the lowest iron- and sulfur-oxidizing bacterial abundance. In conclusion, vegetation successfully prevented the oxidization of sulfide minerals in the tailings, and Imperata cylindrica is the most effective in reducing the number of iron- and sulfur-oxidizing bacteria and helped to prevent the oxidization of sulfide minerals in the long term. Copyright © 2016 Elsevier Ltd. All rights reserved.

Site-Specific Bioconjugation of an Organometallic Electron Mediator to an Enzyme with Retained Photocatalytic Cofactor Regenerating Capacity and Enzymatic Activity

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Sung In Lim

2015-04-01

Full Text Available Photosynthesis consists of a series of reactions catalyzed by redox enzymes to synthesize carbohydrates using solar energy. In order to take the advantage of solar energy, many researchers have investigated artificial photosynthesis systems mimicking the natural photosynthetic enzymatic redox reactions. These redox reactions usually require cofactors, which due to their high cost become a key issue when constructing an artificial photosynthesis system. Combining a photosensitizer and an Rh-based electron mediator (RhM has been shown to photocatalytically regenerate cofactors. However, maintaining the high concentration of cofactors available for efficient enzymatic reactions requires a high concentration of the expensive RhM; making this process cost prohibitive. We hypothesized that conjugation of an electron mediator to a redox enzyme will reduce the amount of electron mediators necessary for efficient enzymatic reactions. This is due to photocatalytically regenerated NAD(PH being readily available to a redox enzyme, when the local NAD(PH concentration near the enzyme becomes higher. However, conventional random conjugation of RhM to a redox enzyme will likely lead to a substantial loss of cofactor regenerating capacity and enzymatic activity. In order to avoid this issue, we investigated whether bioconjugation of RhM to a permissive site of a redox enzyme retains cofactor regenerating capacity and enzymatic activity. As a model system, a RhM was conjugated to a redox enzyme, formate dehydrogenase obtained from Thiobacillus sp. KNK65MA (TsFDH. A RhM-containing azide group was site-specifically conjugated to p-azidophenylalanine introduced to a permissive site of TsFDH via a bioorthogonal strain-promoted azide-alkyne cycloaddition and an appropriate linker. The TsFDH-RhM conjugate exhibited retained cofactor regenerating capacity and enzymatic activity.

RNA-based molecular survey of biodiversity of limestone tombstone microbiota in response to atmospheric sulphur pollution.

Science.gov (United States)

Villa, F; Vasanthakumar, A; Mitchell, R; Cappitelli, F

2015-01-01

Outdoor stoneworks sustain biofilm formation and are constantly at risk of deterioration by micro-organisms. In this study, the biofilm microflora of historic limestone tombstones located in a highly polluted urban environment (Cambridge, MA) and in a less polluted location (Lexington, MA) were compared using comprehensive RNA-based molecular analyses of 16S rRNA gene sequences as well as sequences of genes for different pathways of sulphur metabolism (soxB, apsA, dsrA). The metabolically active micro-organisms detected by denaturing gradient gel electrophoresis analysis of 16S rRNA fragments were predominantly represented by cyanobacteria (belonging to the family Nostocaceae and to the genus Chroococcidiopsis) in both polluted and unpolluted environments. The investigation of soxB, apsA, dsrA transcripts reflected the abundance and the diversity of sulphur-oxidizing and sulphate-reducing bacteria in the Cambridge samples in comparison with the Lexington samples. The investigation revealed that in addition to phototrophic sulphur bacteria belonging to the genera Thiocapsa, Halochromatium, Allochromatium, Thiococcus and Thermochromatium, other sulphate-oxidizing prokaryotes (e.g. the genus Thiobacillus) as well as sequences of Deltaproteobacteria from the genus Desulfovibrio occurred at the polluted urban site. The interactions between the main functional groups retrieved from the limestone tombstones were discussed. The biofilm microflora inhabiting historic limestones are a multi-component open ecosystem sensitively reacting to all environmental factors including air pollutants. Little is known about specific target groups that are active in the biofilm and their physiological functions. For the first time, transcripts involved in important energy-yielding processes were investigated to reveal the metabolic capabilities of the microflora in response to atmospheric sulphur pollution. This work provides novel and important information about the ecology of limestone

Bioprocessing of coal - 10 - an application of microbial flotation to mineral processing

Energy Technology Data Exchange (ETDEWEB)

Nagaoka, T. [and others] [CRIEPI, Abiko-shi (Japan). Abiko Research Lab.

1996-09-01

Microbial flotation for coal desulfurization is being developed. Pyrite in coal is removed by bacterial adhesion by changing the surface property of pyrite. The bacterial adhesion of Thiobacillus ferrooxidans to sulfide minerals (pyrite, galena, molybdenite, chalcocite and millerite), and pyrite removal from the mixture of these sulfide minerals by microbial flotation was investigated. To compare the adhesion of T. ferrooxidans to pyrite with that to the other four minerals mentioned, the surface areas of the minerals, where the bacterium could adhere, was measured. It was observed that the roughness on the mineral surfaces was much smaller than the size of the bacterial cells. Hence, it was suggested that the roughness did not affect the bacterial adhesion to mineral surfaces. Bacterial adhesion to pyrite was compared with that to the other minerals. The amount of adhering bacterium was estimated on the basis of the adherable surface area measured with microscopic method. The amount of adhering cells to pyrite was 421.6 x 10{sup 8} cells/cm{sup 2}. On the other hand, the amounts of adhering cells to the minerals, except for pyrite were in a range of 77.1 to 160.8 x 10{sup 8} cells/cm{sup 2}. The bacterium adheres more to pyrite than to the other minerals, and only adheres to pyrite even if the pyrite is mixed with other minerals. Hence, T. ferrooxidans could adhere selectively to pyrite. Pyrite removal from the mineral mixtures was investigated with microbial flotation. Pyrite removal was in a range of 83.7% to 95.1% and mineral recovery was 72.9% to 100%. The grade of recovered minerals was in a range of 79.2 to 86.0% and that of rejected pyrite was in a range of 78.7 to 90.0%. These results suggest that microbial flotation can be a novel technology for mineral processing.

Extraction of metals from ores by bacterial leaching: present status and future prospects

International Nuclear Information System (INIS)

Kelly, D.P.

1977-01-01

The principal organism effecting bacterial leaching of ferrous and sulfide ores is Thiobacillus ferrooxidans, though other thiobacilli and other bacteria may be involved. The process depends on (a) direct solubilization of metal sulfides by bacterial oxidation; (b) dissolution of metal sulfides or oxides by ferric iron produced by bacterial pyrite oxidation. Mining spoil dumps and low grade ores can be leached for copper or uranium by cheap low-level technology. Dump leaching enables maximum recovery of valuable metal from any ore, but makes possible exploitation of very low grade Cu and U ores. Continuous extraction processes are possible where a continuously growing bacterial culture is fed with pyritic ores (or FeSO 4 or other sulfide) and continuous metal solubilization proceeds. Intimate contact between the bacteria and the ore to be leached (especially with uranium oxide ores) is not always necessary: leaching of UO 2 ores probably depends only on ferric iron reaction with the ore. Degradation of pyrite-containing rocks may also be developed as part of future recovery processes for petroleum from oil shales. Two-stage leaching systems present the best prospect for developing a higher-level technology for metal extraction. State 1: bacterial generation of Fe 3+ from pyrite or a Fe 2+ source; Stage 2: chemical leaching of ore by Fe 3+ in acid solution. Two-stage processes can be surface processes using crushed or milled ores or can be applied to underground solution mining, when an ore (e.g. uranium) can be leached by pumping Fe 3+ solutions through shattered underground deposits, metal recovered (e.g. solvent extraction) and Fe 3+ regenerated by bacterial oxidation at the surface. The use of controlled continuous microbial cultures to generate either bacteria or ferric iron is outlined

Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus "Ferrovum".

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Sophie R Ullrich

Full Text Available Members of the genus "Ferrovum" are ubiquitously distributed in acid mine drainage (AMD waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain "Ferrovum myxofaciens" P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus "Ferrovum" is extremely scarce.In order to access the wider genetic pool of the genus "Ferrovum" we sequenced the genome of a "Ferrovum"-containing mixed culture and successfully assembled the almost complete genome sequence of the novel "Ferrovum" strain JA12.The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct "Ferrovum" species. "Ferrovum" strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that "Ferrovum" strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively.The potential utilisation of urea by "Ferrovum" strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs "Ferrovum" strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin and Acidithiobacillus ferrivorans (iron oxidase indicates the existence of a modified pathway in "Ferrovum" strain JA12

Effects of organic, biological and chemical fertilizers on vegetative indices and essential oil content of coriander (Coriandrum sativum L.

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M Aghhavani Shajari

2016-05-01

Full Text Available This experiment was conducted to study the effects of single and combined application of organic, biological and chemical fertilizers on qualitative and quantitative characteristics of vegetative part of coriander, (Coriandrum sativum L.. The experiment was carried out as split plot in time based on Complete Randomized Block Design with three replications and 12 treatments at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2010-2011. Treatments included: (1 mycorrhiza (Glomus mosseae, (2 biosulfur (Thiobacillus sp., (3 chemical fertilizer (NPK, (4 cow manure, (5 vermicompost, (6 mycorrhiza + chemical fertilizer, (7 mycorrhiza + cow manure, (8 mycorrhiza + vermicompost, (9 biosulfur + chemical fertilizer, (10 biosulfur + cow manure, (11 biosulfur + vermicompost and (12 control. Vegetative parts of coriander were cut at 5% of flowering stage in two dates (19 May and 5 June. Results showed that the highest plant height (28 cm and lateral branches (5.2 were obtained in combined application of biosulfur with cow manure treatment. The highest fresh and dry leaf weight, fresh and dry matter yield and stem dry matter weight were obtained in single application of chemical fertilizer. Single application of biosulfur increased leaf/stem ratio. The highest essential oil percentage and essential oil yield were observed in cow manure treatment (0.2% and 1753 g.ha-1, respectively. The maximum leaf/stem ratio were observed in the first cutting, while the highest lateral branches, stem fresh and dry matter yield, essential oil percentage and essential oil yield were obtained in second cut. Overall, results of this study showed that the plant vegetative yield increased by using chemical fertilizer, while essential oil percentage and essential oil yield of coriander were improved by using organic and biological fertilizers.

A novel approach for rapidly and cost-effectively assessing toxicity of toxic metals in acidic water using an acidophilic iron-oxidizing biosensor.

Science.gov (United States)

Yang, Shih-Hung; Cheng, Kuo-Chih; Liao, Vivian Hsiu-Chuan

2017-11-01

Contamination by heavy metals and metalloids is a serious environmental and health concern. Acidic wastewaters are often associated with toxic metals which may enter and spread into agricultural soils. Several biological assays have been developed to detect toxic metals; however, most of them can only detect toxic metals in a neutral pH, not in an acidic environment. In this study, an acidophilic iron-oxidizing bacterium (IOB) Strain Y10 was isolated, characterized, and used to detect toxic metals toxicity in acidic water at pH 2.5. The colorimetric acidophilic IOB biosensor was based on the inhibition of the iron oxidizing ability of Strain Y10, an acidophilic iron-oxidizing bacterium, by metals toxicity. Our results showed that Strain Y10 is acidophilic iron-oxidizing bacterium. Thiobacillus caldus medium (TCM) (pH 2.5) supplied with both S 4 O 6 2- and glucose was the optimum growth medium for Strain Y10. The optimum temperature and pH for the growth of Strain Y10 was 45 °C and pH 2.5, respectively. Our study demonstrates that the color-based acidophilic IOB biosensor can be semi-quantitatively observed by eye or quantitatively measured by spectrometer to detect toxicity from multiple toxic metals at pH 2.5 within 45 min. Our study shows that monitoring toxic metals in acidic water is possible by using the acidophilic IOB biosensor. Our study thus provides a novel approach for rapid and cost-effective detection of toxic metals in acidic conditions that can otherwise compromise current methods of chemical analysis. This method also allows for increased efficiency when screening large numbers of environmental samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Sulfur Application on Spinach Phytoremedaiton Process of Cadmium in Contaminated Calcareous Soils

Directory of Open Access Journals (Sweden)

Ali Kasraian

2012-07-01

Full Text Available Recently, cadmium (Cd concentration has increased in croplands through sewage sludge and phosphorous fertilizers application. On the other hand, some special methods, like phytoremedation, were introduced in order to decrease soil contamination hazard. Calcium carbonate plays an important role in Cd solubility in highly calcareous soils. Sulfurs oxidation, by dissolving Cd carbonate fraction, may improve phytoremediation efficiency. An experiment was conducted to study the effects of S application (equivalent to 0, 2, 4 and 6 Mg S ha-1 on Diethylene Triamine Pentaacetic Acid  (DTPA extractable Cd and also on Cd uptake and extraction by spinach (Spinacea oleracea L. in calcareous soils which were contaminated by 40mg Cd kg-1. To ensure biological S oxidation, all S-treated samples were inoculated by Thiobacillus spp. and incubated for 50 days. The soil pH, EC and soluble sulfate were affected by S application and it clearly showed that S oxidation process was occurred in Cd treated soils. The most significant change for pH and sulfate were observed at 4 Mg S ha-1 and for electrical conductivity (EC of soil it occurred at 6Mg S ha-1. Application of S had no effect on DTPA extractable Cd in soils whereas; its concentration increased 73.55% in average in plant tissue. Plant dry matter decreased significantly (about 63 percent following Cd application. Although the highest rate of S oxidation was observed at 4 and 6 Mg S ha-1 tٰٰٰhe maximum Cd extraction (2.5µg Cd pot-1 was observed at 2 Mg S ha-1 . This may be due to adverse effect of Cd toxicity and increase of soluble salt resulted by S oxidation in higher level of S application.

Improved quinoa growth, physiological response, and seed nutritional quality in three soils having different stresses by the application of acidified biochar and compost.

Science.gov (United States)

Ramzani, Pia Muhammad Adnan; Shan, Lin; Anjum, Shazia; Khan, Waqas-Ud-Din; Ronggui, Hu; Iqbal, Muhammad; Virk, Zaheer Abbas; Kausar, Salma

2017-07-01

Quinoa (Chenopodium quinoa Willd.) is a traditional Andean agronomical resilient seed crop having immense significance in terms of high nutritional qualities and its tolerance against various abiotic stresses. However, finite work has been executed to evaluate the growth, physiological, chemical, biochemical, antioxidant properties, and mineral nutrients bioavailability of quinoa under abiotic stresses. Depending on the consistency in the stability of pH, intended rate of S was selected from four rates (0.1, 0.2, 0.3, 0.4 and 0.5% S) for the acidification of biochar and compost in the presence of Thiobacillus thiooxidans by pH value of 4. All three soils were amended with 1% (w/w) acidified biochar (BC A ) and compost (CO A ). Results revealed that selective plant growth, yield, physiological, chemical and biochemical improved significantly by the application of BC A in all stressed soils. Antioxidants in quinoa fresh leaves increased in the order of control > CO A  > BC A , while reactive oxygen species decreased in the order of control < CO A  < BC A . A significant reduction in anti-nutrients (phytate and polyphenols) was observed in all stressed soils with the application of BC A . Moreover, incorporation of CO A and BC A reduced the pH of rhizosphere soil by 0.4-1.6 units in all stressed soils, while only BC A in bulk soil decreased pH significantly by 0.3 units. These results demonstrate that BC A was more effective than CO A to enhance the bioavailability, translocation of essential nutrients from the soil to plant and their enhanced bioavailability in the seed. Copyright © 2017. Published by Elsevier Masson SAS.

The effect of plant growth promoting rhizobacteria (PGPR on quantitative and qualitative characteristics of Sesamum indicum L. with application of cover crops of Lathyrus sp. and Persian clover (Trifolium resopinatum L.

Directory of Open Access Journals (Sweden)

M. Jahan

2016-05-01

Full Text Available Cover crops cultivation and application of plant growth rhizobacteria are the key factors to enhance agroecosystem health. A field experiment was conducted at the Research Farm of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2009-2010. A split plot arrangement based on a complete randomized block design with three replications was used. Cultivation and no cultivation of Lathyrus sp. and Persian clover (Trifolium resopinatum in autumn assigned to the main plots. The sub plot factor consisted of three different types of biofertilizers plus control, including 1-nitroxin (containing of Azotobacter sp. and Azospirillum sp., 2- phosphate solubilizing bacteria (PSB (containing of Bacillus sp. and Pseudomonas sp., 3- biosulfur (containing of Thiobacillus ssp. and 4- control (no fertilizer. The results showed the effect of cover crops on seed number and seed weight per plant, biological and seed yield was significant, as the seed yield increased of 9 %. In general, biofertilizers showed superiority due to the most studied traits compared to control. Nitroxin, PSB and biosulfur increased biological yield of 44, 28 and 26 % compared to control, respectively. Cover crops and biofertilizers interactions, showed significant effect on all studied traits, as the highest and the lowest harvest index resulted in cover crop combined with biofertilizers (22.1% and cultivation and no cultivation of cover crops combined with control (15.3%, respectively. The highest seed oil and protein content resulted from cover crops plus biofertilizers (42.4% and cover crops plus PSB (22.5%, respectively. In general, the results showed cover crops cultivation in combination with biofertilizers application could be an ecological alternative for chemical fertilizers, in addition of achieving advantages of cover crops. According to the results, it should be possible to design an ecological cropping system and produce appropriate and healthy

NOTE TASSONOMICHE E NOMENCLATORIALI SU ALCUNE SPECIE PALEARTICHE DI SIBINIA E TYCHIUS (COLEOPTERA, CURCULIONIDAE

Directory of Open Access Journals (Sweden)

Roberto Caldara

2009-10-01

. = Sibinia sobrina Voss, 1936 n. syn.; Sibinia variata Gyllenhal, 1836 = Sibinia rubripes Desbrochers, 1907 n. syn.; Sibi­nia viscariae (Linnaeus = Sibinia submeticollis Desbrochers, 1908 n. syn.; Tychiusar­ gentatus Chevrolat, 1859 = Tychius dimidiatipennis Desbrochers, 1873 n. syn. = Tychius argenteosquamosus Desbrochers, 1908 n. syn. = Tychius seductor Desbrochers, 1908 n. syn.; Tychius medicaginis C. Brisout, 1862 = Tychius griseus Petri, 1915 (non Schaeffer, 1908 n. syn.; Tychius breviusculus Desbrochers, 1873 = Tychius humeralis Desbrochers, 1908 n. syn.; Tychius cinnamomeus Kiesenwetter, 1851 = Tychius adspersus Desbrochers, 1908 n. syn. = Tychius barcelonicus Desbrochers, 1908 n. syn.; Tychius cu­prifer (Panzer, 1799 = Myllocerus subcostatus Kolenati, 1858 n. syn.; Tychius cuprinus Rosenhauer, 1856 = Tychius tuberculirostris Hustache, 1944 n. syn.; Tychius dieckmanni Caldara, 1986 = Lepidotychius babaevi Bajtenov & Soyunov, 1990 n. syn.; Tychius ele­gantulus C. Brisout, 1862 = Tychius pulcher Pic, 1925 n. syn.; Tychius elongatulus Desbrochers, 1897 = Tychius longitarsis Desbrochers, 1898 n. syn.; Tychius grenieri C. Brisout, 1861 = Tychius sparsus Hustache, 1944; Tychius immaculicollis Desbrochers, 1907 = Tychius elegans Desbrochers, 1896 (non Brullé, 1832 = Tychius ifranensis Hustache, 1944 n. syn. = Tychius kocheri Hustache, 1944 n. syn. = Tychius teluetensis Hustache, 1944 n. syn.; Tychius lautus Gyllenhal, 1836 = Tychius obductus Hochhuth, 1851 n. syn. = Tychius cilicensis Pic, 1905 n. syn.; Tychius oschianus Faust, 1885 = Tychius pubicol­lis Petri, 1915 n. syn.; Tychius pardalis Escalera, 1914 = Tychius circulatus Hustache, 1944 n. syn.; Tychius picirostris (Fabricius, 1787 = sTychius parvulus Stephens, 1831 n. syn.; Tychius polylineatus (Germar, 1824 = Tychius orbiculatus Hustache, 1944 n. syn.; Tychius stephensi Schoenherr, 1836 = Tychius pallidicornis Desbrochers, 1875 n. syn. Sono considerati nomi infrasubspecifici e pertanto non utilizzabili: Sibinia

System evaluation and microbial analysis of a sulfur cycle-based wastewater treatment process for Co-treatment of simple wet flue gas desulfurization wastes with freshwater sewage.

Science.gov (United States)

Qian, Jin; Liu, Rulong; Wei, Li; Lu, Hui; Chen, Guang-Hao

2015-09-01

A sulfur cycle-based wastewater treatment process, namely the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated process (SANI(®) process) has been recently developed for organics and nitrogen removal with 90% sludge minimization and 35% energy reduction in the biological treatment of saline sewage from seawater toilet flushing practice in Hong Kong. In this study, sulfate- and sulfite-rich wastes from simple wet flue gas desulfurization (WFGD) were considered as a potential low-cost sulfur source to achieve beneficial co-treatment with non-saline (freshwater) sewage in continental areas, through a Mixed Denitrification (MD)-SANI process trialed with synthetic mixture of simple WFGD wastes and freshwater sewage. The system showed 80% COD removal efficiency (specific COD removal rate of 0.26 kg COD/kg VSS/d) at an optimal pH of 7.5 and complete denitrification through MD (specific nitrogen removal rate of 0.33 kg N/kg VSS/d). Among the electron donors in MD, organics and thiosulfate could induce a much higher denitrifying activity than sulfide in terms of both NO3(-) reduction and NO2(-) reduction, suggesting a much higher nitrogen removal rate in organics-, thiosulfate- and sulfide-based MD in MD-SANI compared to sulfide alone-based autotrophic denitrification in conventional SANI(®). Diverse sulfate/sulfite-reducing bacteria (SRB) genera dominated in the bacterial community of sulfate/sulfite-reducing up-flow sludge bed (SRUSB) sludge without methane producing bacteria detected. Desulfomicrobium-like species possibly for sulfite reduction and Desulfobulbus-like species possibly for sulfate reduction are the two dominant groups with respective abundance of 24.03 and 14.91% in the SRB genera. Diverse denitrifying genera were identified in the bacterial community of anoxic up-flow sludge bed (AnUSB) sludge and the Thauera- and Thiobacillus-like species were the major taxa. These results well explained the successful operation of the lab

Effect of particle-particle shearing on the bioleaching of sulfide minerals.

Science.gov (United States)

Chong, N; Karamanev, D G; Margaritis, A

2002-11-05

The biological leaching of sulfide minerals, used for the production of gold, copper, zinc, cobalt, and other metals, is very often carried out in slurry bioreactors, where the shearing between sulfide particles is intensive. In order to be able to improve the efficiency of the bioleaching, it is of significant importance to know the effect of particle shearing on the rate of leaching. The recently proposed concept of ore immobilization allowed us to study the effect of particle shearing on the rate of sulfide (pyrite) leaching by Thiobacillus ferrooxidans. Using this concept, we designed two very similar bioreactors, the main difference between which was the presence and absence of particle-particle shearing. It was shown that when the oxygen mass transfer was not the rate-limiting step, the rate of bioleaching in the frictionless bioreactor was 2.5 times higher than that in a bioreactor with particle friction (shearing). The concentration of free suspended cells in the frictionless bioreactor was by orders of magnitude lower than that in the frictional bioreactor, which showed that particle friction strongly reduces the microbial attachment to sulfide surface, which, in turn, reduces the rate of bioleaching. Surprisingly, it was found that formation of a layer of insoluble iron salts on the surface of sulfide particles is much slower under shearless conditions than in the presence of particle-particle shearing. This was explained by the effect of particle friction on liquid-solid mass transfer rate. The results of this study show that reduction of the particle friction during bioleaching of sulfide minerals can bring important advantages not only by increasing significantly the bioleaching rate, but also by increasing the rate of gas-liquid oxygen mass transfer, reducing the formation of iron precipitates and reducing the energy consumption. One of the efficient methods for reduction of particle friction is ore immobilization in a porous matrix. Copyright 2002

A Novel Uncultured Bacterium of the Family Gallionellaceae: Description and Genome Reconstruction Based on the Metagenomic Analysis of Microbial Community in Acid Mine Drainage.

Science.gov (United States)

Kadnikov, V V; Ivasenko, D A; Beletsky, A V; Mardanov, A V; Danilova, E V; Pimenov, N V; Karnachuk, O V; Ravin, N V

2016-07-01

Drainage waters at the metal mining areas often have low pH and high content of dissolved metals due to oxidation of sulfide minerals. Extreme conditions limit microbial diversity in- such ecosystems. A drainage water microbial community (6.5'C, pH 2.65) in an open pit at the Sherlovaya Gora polymetallic open-cast mine (Transbaikal region, Eastern Siberia, Russia) was studied using metagenomic techniques. Metagenome sequencing provided information for taxonomic and functional characterization of the micro- bial community. The majority of microorganisms belonged to a single uncultured lineage representing a new Betaproteobacteria species of the genus Gallionella. While no.acidophiles are known among the cultured members of the family Gallionellaceae, similar 16S rRNA gene sequences were detected in acid mine drain- ages. Bacteria ofthe genera Thiobacillus, Acidobacterium, Acidisphaera, and Acidithiobacillus,-which are com- mon in acid mine drainage environments, were the minor components of the community. Metagenomic data were -used to determine the almost complete (-3.4 Mb) composite genome of the new bacterial. lineage desig- nated Candidatus Gallionella acididurans ShG14-8. Genome analysis revealed that Fe(II) oxidation probably involved the cytochromes localized on the outer membrane of the cell. The electron transport chain included NADH dehydrogenase, a cytochrome bc1 complex, an alternative complex III, and cytochrome oxidases of the bd, cbb3, and bo3 types. Oxidation of reduced sulfur compounds probably involved the Sox system, sul- fide-quinone oxidoreductase, adenyl sulfate reductase, and sulfate adenyltransferase. The genes required for autotrophic carbon assimilation via the Calvin cycle were present, while no pathway for nitrogen fixation was revealed. High numbers of RND metal transporters and P type ATPases were probably responsible for resis- tance to heavy metals. The new microorganism was an aerobic chemolithoautotroph of the group of

Microbial control of hydrogen sulfide production

Energy Technology Data Exchange (ETDEWEB)

Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J. [Univ. of Oklahoma, Tulsa, OK (United States)] [and others

1995-12-31

A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

A field demonstration of the microbial treatment of sour produced water

Energy Technology Data Exchange (ETDEWEB)

Sublette, K.L. [Univ. of Tulsa, OK (United States); Morse, D.; Raterman, K. [Amoco Production Co., Tulsa, OK (United States)

1995-12-31

The potential for detoxification and deodorization of sulfide-laden water (sour water) by microbial treatment was evaluated at a petroleum production site under field conditions. A sulfide-tolerant strain of the chemautotroph and facultative anaerobe, Thiobacillus denitrificans, was introduced into an oil-skimming pit of the Amoco Production Company LACT 10 Unit of the Salt Creek Field, Wyoming. Field-produced water enters this pit from the oil/water separation treatment train at an average flowrate of 5,000 bbl/D (795 m{sup 3}/D) with a potential maximum of 98,000 bbl/D (15,580 m{sup 3}/D). Water conditions at the pit inlet are 4,800 mg/l TDS, 100 mg/l sulfide, pH 7.8, and 107{degrees}F. To this water an aqueous solution of ammonium nitrate and diphosphorous pentoxide was added to provide required nutrients for the bacteria. The first 20% of the pit was aerated to a maximum depth of 5 ft (1.5 m) to facilitate the aerobic oxidation of sulfide. No provisions for pH control or biomass recovery and recycle were made. Pilot operations were initiated in October 1992 with the inoculation of the 19,000 bbl (3,020 m{sup 3}) pit with 40 lb (18.1 kg) of dry weight biomass. After a brief acclimation period, a nearly constant mass flux of 175 lb/D (80 kg/D) sulfide was established to the pit. Bio-oxidation of sulfide to elemental sulfur and sulfate was immediate and complete. Subsequent pilot operations focused upon process optimization and process sensitivity to system upsets. The process appeared most sensitive to large variations in sulfide loading due to maximum water discharge events. However, recoveries from such events could be accomplished within hours. This paper details all pertinent aspects of pilot operation, performance, and economics. Based on this body of evidence, it is suggested that the oxidation of inorganic sulfides by T denitrificans represents a viable concept for the treatment of sour water coproduced with oil and gas.

Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus “Ferrovum”

Science.gov (United States)

Ullrich, Sophie R.; Poehlein, Anja; Tischler, Judith S.; González, Carolina; Ossandon, Francisco J.; Daniel, Rolf; Holmes, David S.; Schlömann, Michael; Mühling, Martin

2016-01-01

Background Members of the genus “Ferrovum” are ubiquitously distributed in acid mine drainage (AMD) waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain “Ferrovum myxofaciens” P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus “Ferrovum” is extremely scarce. Objective In order to access the wider genetic pool of the genus “Ferrovum” we sequenced the genome of a “Ferrovum”-containing mixed culture and successfully assembled the almost complete genome sequence of the novel “Ferrovum” strain JA12. Phylogeny and Lifestyle The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct “Ferrovum” species. “Ferrovum” strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that “Ferrovum” strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively. Unique Metabolic Features The potential utilisation of urea by “Ferrovum” strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs “Ferrovum” strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin) and Acidithiobacillus

Bacterial diversity exploration in hydrocarbon polluted soil: metabolic potential and degrader community evolution revealed by isotope labeling

International Nuclear Information System (INIS)

Martin, F.

2011-01-01

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds produced by incomplete combustion of organic matter. They are a source of environmental pollution, especially associated to oil product exploitation, and represent a threat for living organisms including human beings because of their toxicity. Many bacteria capable of degrading PAHs have been isolated and studied. However, since less than 5% of soil bacteria can be cultivated in the laboratory, bacterial species able to degrade PAHs in situ have been poorly studied. The first goal of this study was to identify bacteria that degrade PAHs in soil using culture-independent molecular methods. To this end, a strategy known a stable isotope probing has been implemented based on the use of phenanthrene, a three rings PAH, in which the natural isotope of carbon was replaced by 13 C. This molecule has been introduced as a tracer in microcosms containing soil from a constructed wetlands collecting contaminated water from highway runoff. Bacteria having incorporated the 13 C were then identified by 16 S rRNA gene sequence analysis after PCR amplification from labeled genomic DNA extracted from soil. The results show that so far little studied Betaproteobacteria, belonging to the genera Acidovorax, Rhodoferax, Hydrogenophaga and Thiobacillus, as well as Rhodocyclaceae, were the key players in phenanthrene degradation. Predominance of Betaproteobacteries was established thanks to quantitative PCR measurements. A dynamic analysis of bacterial diversity also showed that the community structure of degraders depended on phenanthrene bioavailability. In addition, the phylogenetic diversity of ring-hydroxylating di-oxygenases, enzymes involved in the first step of PAH degradation, has been explored. We detected new sequences, mostly related to di-oxygenases from Sphingomonadales and Burkholderiales. For the first time, we were able to associate a catalytic activity for oxidation of PAHs to partial gene sequences

Search for the algorithm of genes distribution during the process of microbial evolution

Science.gov (United States)

Pikuta, Elena V.

2015-09-01

Previous two and three dimensional graph analysis of eco-physiological data of Archaea demonstrated specific geometry for distribution of major Prokaryotic groups in a hyperboloid function. The function of a two-sheet hyperboloid covered all known biological groups, and therefore, could be applied for the entire evolution of life on Earth. The vector of evolution was indicated from the point of hyper temperature, extreme acidity and low salinity to the point of low temperature and increased alkalinity and salinity. According to this vector, the following groups were chosen for the gene screening analysis. In the vector "High-Temperature → Low-Temperature" within extreme acidic pH (0-3), it is: 1) the hyperthermophilic Crenarchaeota - order Sulfolobales, 2) moderately thermophilic Euryarchaeota - Class Thermoplasmata, and 3) mesophilic acidophiles- genus Thiobacillus and others. In the vector "Low pH → High pH" the following groups were selected in three temperature ranges: a) Hyperthermophilic Archaea and Eubacteria, b) moderately thermophilic - representatives of the genera Anaerobacter and Anoxybacillus, and c) mesophilic haloalkaliphiles (Eubacteria and Archaea). The genes associated with acidophily (H+ pump), chemolitho-autotrophy (proteins of biochemichal cycles), polymerases, and histones were proposed for the first vector, and for the second vector the genes associated with halo-alkaliphily (Na+ pumps), enzymes of organotrophic metabolisms (sugar- and proteolytics), and others were indicated for the screening. Here, an introduction to the phylogenetic constant (ρη) is presented and discussed. This universal characteristic is calculated for two principally different life forms -Prokaryotes and Eukaryotes; Existence of the second type of living forms is impossible without the first one. The number of chromosomes in Prokaryotic organisms is limited to one (with very rare exceptions, to two), while in Eukaryotic organisms this number is larger. Currently

蔬菜连作改为蓝莓种植后土壤细菌群落多样性变化的分析%Changes in Soil Bacterial Community Diversity Caused by Cropping System Alteration from Vegetable Continuous Cropping to Blueberry Planting

Institute of Scientific and Technical Information of China (English)

祁石刚; 田畅; 却枫; 徐志胜; 王枫; 熊爱生

2016-01-01

基于第二代Illumina Miseq高通量测序平台，利用16S rDNA技术分析了江苏省宿迁市蔬菜连作改为蓝莓种植后土壤细菌多样性的分布和细菌群落多样性的变化。结果表明：Kaistobacter、假交替单胞菌属（ Pseud oaltre omno as）、硫杆状菌属（ Thiobacillus）、Rubritalea、浮霉菌属（ Planctomyces）、Lysobacter、纤维弧菌属（ Cellvibrio）、噬氢菌属（ Hdy roeg nohp a-ga ）、鞘脂单胞菌属（ Sphingomona s）和热单胞菌属（ Thermomonas）为蔬菜连作改为蓝莓种植后土壤细菌的主要类群； Spo-rosarcina、Alicyclobacillus、氨氧化古细菌（ Candidatus nitrososphaera）和P ontibatc er是蔬菜连作土壤细菌的主要类群；蔬菜连作改为种植蓝莓后，土壤细菌多样性和丰度降低，优势菌群也出现了显著的变化。%Based on the second-generation high-throughput sequencing platform Illumina Miseq , using the 16S rDNA gene sequencing technology, the author analyzed the changes in soil bacterial community diversity caused by the cropping system altera-tion from vegetable continuous cropping to blueberry planting in Suqian city of Jiangsu province .The results showed that:Kaisto-bacter, Pseudoalteromonas, Thiobacillus, Rubrti alea, Planctomyces, Lysobacter, Cellvibrio, Hydrogenophaga, Sphingomonas and Thermomonas were the dominant bacterial populations in the soil after cropping system alteration from vegetable continuous crop-ping to blueberry planting;Sporosarcina, Alicyclobacillus, Cand idatus nitrososphaera and Pontbi acter were the dominant bacterial populations in the soil of continuous-cropping vegetable field;after the alteration from vegetable continuous cropping to blueberry planting, the diversity and abundance of soil bacteria were reduced , and the dominant bacterial community also changed obvious-ly.

Iron sulfide oxidation as influenced by calcium carbonate application

Energy Technology Data Exchange (ETDEWEB)

Hossner, L.R.; Doolittle, J.J. [Texas A& M University, College Station, TX (USA). Dept. of Soil & Crop Science

2003-06-01

Two overburden materials, with different FeS{sub 2} contents (1.9 and 4.1%) and low acid neutralization potential, were limed with CaCO{sub 3} at rates of 0, 25,50,75, 100, and 125% based on the amount of CaCO{sub 3} needed to provide an acid-base account deficit (A/B-a) of zero (A/B-a = neutratization potential - potential acidity - exchangeable acidity). The limed overburden materials were inoculated with Thiobacillus ferrooxidans and leached weekly with deionized water. Residual FeS{sub 2} and CaCO{sub 3} were determined in samples over a 378-d period. Oxidation followed zero-order kinetics with respect to FeS{sub 2} concentration at pH values greater than 4 and first-order kinetics at pH values less than 4. Zero-order oxidation rates ranged from 0.01 to 0.46 {mu}mol g{sup -1} d{sup -1} in the overburden with 1.9% FeS{sub 2} and from 0.01 to 0.22 {mu}mol g{sup -1} d{sup -1} in the overburden with 4.1% FeS{sub 2}. Oxidation following the first-order rate law had a first-order rate constant of 0.03 d{sup -1} in the 1.9% FeS{sub 2} overburden and 0.01 d{sup -1} in the 4.1% FeS{sub 2} overburden. The calculated half-life was 23 d for the 1.9% FeS{sub 2} overburden and 69 d for the 4.1% FeS{sub 2} overburden. Additions of CaCO{sub 3} affected FeS{sub 2} oxidation by controlling the pH of the system. Liming to greater than 50% of the acid-base account deficit did not significantly affect the zero-order oxidation rate. Dissolution of the applied CaCO{sub 3} was found to be faster than the oxidation of FeS{sub 2} at pH values greater than 4. It was projected that at lime rates up to 125%, the CaCO{sub 3} would dissolve and leach out of the system before all the FeS{sub 2} oxidized, leaving the potential for acid minesoil formation.

Impact of clay mineral, wood sawdust or root organic matter on the bacterial and fungal community structures in two aged PAH-contaminated soils.

Science.gov (United States)

Cébron, Aurélie; Beguiristain, Thierry; Bongoua-Devisme, Jeanne; Denonfoux, Jérémie; Faure, Pierre; Lorgeoux, Catherine; Ouvrard, Stéphanie; Parisot, Nicolas; Peyret, Pierre; Leyval, Corinne

2015-09-01

development of PAH-degrading bacteria holding Gram-negative PAH-ring hydroxylating dioxygenase, catechol-1,2-dioxygenase and catechol-2,3-dioxygenase genes. Regarding the total community structure, bacteria closely related to Thiobacillus (β-Proteobacteria) and Steroidobacter (γ-Proteobacteria) genera were favoured by wood sawdust amendment. In both soils, plant rhizospheres induced the development of fungi belonging to Ascomycota and related to Alternaria and Fusarium genera. Bacteria closely related to Luteolibacter (Verrucomicrobia) and Microbacterium (Actinobacteria) were favoured in alfalfa and ryegrass rhizosphere.

Chemical composition influence of cement based mortars on algal biofouling

Science.gov (United States)

Estelle, Dalod; Alexandre, Govin; Philippe, Grosseau; Christine, Lors; René, Guyonnet; Denis, Damidot

2013-04-01

The main cause of building-facade biodegradation is the growth of microorganisms. This phenomenon depends on several parameters such as the geographical situation, the environmental conditions and the surface state of the substrate. Several researches have been devoted to the study of the effect of porosity and roughness on the biofouling of stones and mortars. However, none of them have addressed the influence of the mortar chemistry on the microorganism growth kinetic. The main objective of this study is to highlight the influence of the mortar chemistry in relationship with its physical properties on biological weathering. Earlier work showed a good resistance of Calcium Aluminate Cements to biodeterioration by acidogenic bacteria (Thiobacillus) and fungi (Alternaria alternata, Aspergillus Niger and Coniosporium uncinatum). In order to characterize the influence of the mortar chemistry on biofouling, two Portland cements and two alumina cements are used. Among micro-organisms able to grow, green algae are most involved in the aesthetic deterioration of facades. Indeed, they can colonize any type of media and can be a source of nutrients for other micro-organisms such as fungi. The green algae Klebsormidium flaccidum is chosen because of its representativeness. It is indeed the species the most frequently identified and isolated from samples taken on sites. The biofouling kinetic is followed on samples exposed outdoor and on samples tested in a laboratory bench which consists in spraying an algae culture on mortar specimens. The results obtained by in situ trials are compared with the results obtained on the laboratory bench. The microorganism growth kinetic is measured by image analysis. To improve the detection of algae on the surface of the cementitious samples, the raw image is converted in the YIQ color space. Y, I and Q correspond respectively to luminance, in-phase, and quadrature. On the Q channel, the areas covered by algae and the areas of clean mortar

Denitrification, anammox and fixed nitrogen removal in the water column of a tropical great lake

Science.gov (United States)

Darchambeau, François; Roland, Fleur; Crowe, Sean A.; De Brabandere, Loreto; Llirós, Marc; Garcia-Armisen, Tamara; Inceoglu, Ozgul; Michiels, Céline; Servais, Pierre; Morana, Cédric D. T.; Bouillon, Steven; Meysman, Filip; Veuger, Bart; Masilya, Pascal M.; Descy, Jean-Pierre; Borges, Alberto V.

2013-04-01

If rates of microbial denitrification in aquatic systems are poorly constrained, it is much more the case for tropical water bodies. Lake Kivu [2.50° S 1.59° S, 29.37° E 28.83° E] is one of the great lakes of the East African Rift. It is an oligotrophic lake characterized by anoxic deep waters rich in dissolved gases (methane and carbon dioxide) and nutrients, and by well oxygenated and nutrient-depleted surface waters. During the seasonally stratified rainy season (October to May), a nitrogenous zone characterized by the accumulation of nitrite (NO2-) and nitrate (NO3-) is often observed in the lower layer of the mixolimnion. It results from nitrification of ammonium released by decaying organic matter. With the seasonal uplift of the oxygen minimum zone, the nitrogenous zone becomes anoxic and might be the most preferential area for fixed nitrogen (N) removal in Lake Kivu. Our work aimed at identifying and quantifying the processes of N losses by denitrification and/or anammox in the nitrogenous zone of the Lake Kivu water column. During 5 sampling campaigns (March 2010, October 2010, June 2011, February 2012 and September 2012), isotopic labelling experiments were used to quantify denitrification and anammox rates along vertical profiles at two pelagic stations of the main lake. Moreover, N2:Ar ratios were estimated during the September 2012 campaign, and 16S rDNA pyrosequencing was used to describe bacterial community composition during the last 2 campaigns. No bacteria related to organisms performing anammox was observed and labelling experiments failed to detect anammox at any locations and any depths. In Lake Kivu, denitrifying bacteria were mainly related to Denitratisoma and Thiobacillus genus. Significant denitrification rates were observed at several occasions, especially under the oxic-anoxic interface in the bottom of the nitracline. The annual average denitrification rate was estimated at ~150 μmoles N m-2 d-1. Denitrification was not the only

First Microbial Community Assessment of Borehole Fluids from the Deep Underground Science and Engineering Laboratory (DUSEL)

Science.gov (United States)

Moser, D. P.; Anderson, C.; Bang, S.; Jones, T. L.; Boutt, D.; Kieft, T.; Sherwood Lollar, B.; Murdoch, L. C.; Pfiffner, S. M.; Bruckner, J.; Fisher, J. C.; Newburn, J.; Wheatley, A.; Onstott, T. C.

2010-12-01

Proteobacteria and closely related to known or expected aerobes including: Thiobacillus, Siderooxidans, Leptothrix, Hydrogenophaga, Pseaudomonas, Methylomonas and Thiothrix, consistent with possible mine water or air contamination. Conversely, Deltaproteobacteria and Firmicute clones, often very closely related to others detected from deep mine or sediment habitats, suggests a deep subsurface component as well. Archaeal clones from 4100L were dominated by a deeply-branching clade with no cultivated representatives; whereas, those from 4850 were mostly related to known methanogens (e.g. Methanolobus). Collectively, this dataset suggests mixed end-member or deeply-sourced water partially overprinted by mine-related artifacts. However, until more is known concerning the deep hydrogeology of this system, it will be difficult to ascertain indigenous from impacted microbial communities in DUSEL.

Sulfur isotopic fractionation of carbonyl sulfide during degradation by soil bacteria and enzyme

Science.gov (United States)

Kamezaki, Kazuki; Hattori, Shohei; Ogawa, Takahiro; Toyoda, Sakae; Kato, Hiromi; Katayama, Yoko; Yoshida, Naohiro

2017-04-01

Carbonyl sulfide (COS) is an atmospheric trace gas that possess great potential for tracer of carbon cycle (Campbell et al., 2008). COS is taken up by vegetation during photosynthesis like absorption of carbon dioxide but COS can not emit by respiration of vegetation, suggesting possible tracer for gross primary production. However, some studies show the COS-derived GPP is larger than the estimates by using carbon dioxide flux because COS flux by photolysis and soil flux are not distinguished (e.g. Asaf et al., 2013). Isotope analysis is a useful tool to trace sources and transformations of trace gases. Recently our group developed a promising new analytical method for measuring the stable sulfur isotopic compositions of COS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ enabling us to easily analyze sulfur isotopes in COS (Hattori et al., 2015). Soil is thought to be important as both a source and a sink of COS in the troposphere. In particular, soil has been reported as a large environmental sink for atmospheric COS. Bacteria isolated from various soils actively degrade COS, with various enzymes such as carbonic anhydrase and COSase (Ogawa et al., 2013) involved in COS degradation. However, the mechanism and the magnitude of bacterial contribution in terms of a sink for atmospheric COS is still uncertain. Therefore, it is important to quantitatively evaluate this contribution using COS sulfur isotope analysis. We present isotopic fractionation constants for COS by laboratory incubation experiments during degradation by soil bacteria and COSase. Incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia, Cupriavidus, and Thiobacillus, isolated from natural soil or activated sludge and enzyme purified from a bacteria. As a result, the isotopic compositions of OCS were increased during degradation of

The effect of organic, biological and chemical fertilizers on yield, essential oil percentage and some agroecological characteristics of summer savory (Satureja hortensis L. under Mashhad conditions

Directory of Open Access Journals (Sweden)

E Gholami Sharafkhane

2016-05-01

Full Text Available Introduction Savory (Satureja hortensis L. is an annual herbaceous plant that belongs to the Lamiaceae family. Nowadays, the use of biofertilizers is increased in agriculture and their role in increasing the crops production has been demonstrated in many research works (Vessey, 2003; Chen, 2006; Mahfouz & Sharaf- Eldin, 2007. One of the most important visions is sustainable production of enough food plus paying attention to social, economical and environmental aspects. (Gliessman, 1998 stated that the first step to achieve this goal is optimization and improvement of resources use efficiencies. Considering medicinal importance of savory and its role in the food and pharmaceutical industries (Omidbeigi, 2000, beside the limited nutrient resources and need to increase healthy production through using ecological inputs, this study was designed and conducted aimed to evaluate agroecological characteristics of savory as affected by the application of bio fertilizers, chemical and organic fertilizers under Mashhad conditions. Materials and methods In order to study the effects of organic, biological and chemical fertilizers on quantitative and qualitative characteristics of summer savory, a split-plot design based on RCBD with three replications was conducted during the growing season of 2012 at the Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran. Different levels of cattle manure (0 and 25 t.ha-1 were assigned to the main plots and different types of bio fertilizers (Nitroxin, containing Azotobacter sp. and Azospirillum sp., Biophosphor, containing phosphate-solubilizing bacteria (Bacillus sp. and Pseudomonas sp., Biosulfur, containing sulfur-solubilizing bacteria (Thiobacillus ssp., combination of Nitroxin+Biophosphor+ Biosulfur, vermicompost (7 t.ha-1, chemical fertilizers (NPK: 60, 60 and 70 kg.ha-1 and control (no fertilizer were used in the sub- plots. Results and discussion According to the results

Status Report from Yugoslavia [Processing of Low-Grade Uranium Ores

Energy Technology Data Exchange (ETDEWEB)

Bunji, B [Institute for Technology of Nuclear and Other Raw Materials, Belgrade, Yugoslavia (Serbia)

1967-06-15

barren solution has resulted in important savings on reagent. The overall economy compared under local conditions with ion-exchange or solvent extraction is in favour of the reduction process. Some research work on heap leaching and leaching in situ is included in our activities. In connection with the conditions at Kalna it was possible to carry out large-scale heap leaching and leaching in situ. The former was carried out on waste rocks with a uranium content below the cut-off grade. To avoid solution losses, the surface area from the heap pile is covered with thin plastic sheets. Good drainage from the bottom is obtained by using perforated 10-in. asbestos-concrete pipes. The technique of construction of the heap pile is as usual, and mostly depends on local conditions. The heap leach pile is about 12 m high. The solution retention time is about 8 days. The barren solution from the reduction plant or mine water with a uranium content in the range of 2 to 6 g/m{sup 3} is used for the heap leaching. The pregnant solution is returned into the processing plant. Because the heap leach pile obtained is practically without any charge, the operating and the construction costs of the heap pile need only be in balance with the value of the recovered uranium. Investigation of bacterial leaching has shown some influence on the leaching rate. The bacteria belonging to the Thiobacillus-Ferrobacillus group were obtained from mine water, selected and cultivated. It seems that the concentration of bacteria has some influence on the extraction time and percentage of extracted uranium, and it can be said that the application of bacteria in heap leaching and leaching in situ will in the future be one of the most effective methods of uranium extraction from ore that is below cut-off grade. (author)

Characterization of microbial communities in former neutral uranium mines in Saxony and studies on the microbial immobilization of uranium and arsenic

International Nuclear Information System (INIS)

Gagell, Corinna

2015-01-01

Abandoned uranium mines contribute significantly to the emission of contaminants such as uranium and arsenic into partly densely populated regions due to emerging flood water. To get a deeper understanding of ongoing processes in underground environments and for the development of alternative strategies to conventional, cost-intensive water treatment, the objective of this thesis was to characterize microbial communities from three former uranium mines in Saxony, namely Poehla, Schlema, and Zobes representing different flooding stages and to investigate the microbial influence on the mobility of uranium and arsenic. To find out which microorganisms could affect hydrochemical processes in underground environments, the diversity and compostion of microbial communities was investigated by pyrosequencing of a 16S rRNA gene (16S rDNA) fragment together with CARD-FISH. Though cluster analyses showed that planktonic communities differed with regard to bacterial composition between the three uranium mines, all were dominated by chemolithotrophic sulfur oxidizers of Betaproteobacteria with members of genus Thiobacillus and Sulfuritalea and Epsilonproteobacteria belonging to Sulfuricurvum and Sulfurimonas. Unlike planktonic communities, in situ biofilms grown on BACTRAPs during three month of exposition in flood water consisted of metal and sulfate reducing Deltaproteobacteria to a substantial or even dominant proportion based on pyrosequencing results. In biofilm communities from Zobes mainly Geobacter sp. were detected which are known Fe(III)- and U(VI)-reducing bacteria. Although CARD-FISH analysis revealed that Archaea represented only a very small part of the planktonic communities, planktonic Euryarchaeota of the Thermoprotei class were detected in all mines by pyrosequencing. In planktonic communities and 3-month biofilms of Poehla and Zobes methanogenic Crenarchaeota, especially Methanobacteria and partially Methanomicrobia, were determined, too. 16S rRNA analysis

The Effects of Soil Amendments and Bio-fertilizers Inoculation on Morphological Characteristics and Yield of Echium amoenum

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M.B. Amiri

2017-10-01

one of the most important medicinal plants in Iranian traditional medicine. Petals of Iranian oxtongue have been advocated for a variety of effects such as demulcent, anti-inflammatory and analgesic, especially for common cold, anxiolytic, sedative and other psychiatric symptoms including obsession in folk medicine of Iran. Despite many research on the effects of organic acids and bio-fertilizers on different crops, there is scarce information on the effects of these factors for many medicinal plants. Therefore, in this study effect of organic acids and bio-fertilizers on morphological characteristics and yield of Echium amoenum in a low input cropping system was studied. Materials and methods: In order to evaluate the effects of soil amendments and different bio-fertilizers on morphological characteristics and seed yield of Echium amoenum, an experiment was conducted based on randomized complete block design with three replications during 2011-2013 growing seasons, at the Research Farm of Ferdowsi University of Mashhad, Iran. Treatments were eight different types of soil amendments and bio-fertilizers concluding: 1 Humic acid, 2 Fulvic acid, 3 Nitroxin® (Azotobacter spp. and Azospirillum spp., 4 Biophosphorous® (Bacillus sp. and Pseudomonas sp., 5 Biosulfur® (Thiobacillus spp., 6 Mycorrhiza (Glomus mosseae, 7 Mycorrhiza (Glomus intraradices, and 8 no fertilizer as control. Result and Discussion: The results showed that mycorrhiza species increased flower yield compared with control, as the flower yield in treatments of G. mosseae and G. intraradices were 24 and 11 percent more than control, respectively. Soil amendments and different bio-fertilizers increased the number of flower cycle per plant compared with control. Although the effect of biophosphorous® was more pronounced, as the number of flower cycle per plant increased from 342 to 1322 cycles in control and biophosphorous® , respectively. Humic acid treatment increased seed yield, biological yield, seed

Effects of Single and Combined Application of Organic, Biological and Chemical Fertilizers on Quantitative and Qualitative Yield of Coriander (Coriandrum sativum

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M. Aghhavani Shajari

2016-07-01

Full Text Available Introduction: Medicinal plants were one of the main natural resources of Iran from ancient times. Coriander (Coriandrum sativum L. is from Apiaceae family that it has cultivated extensively in the world. Management and environmental factors such as nutritional management has a significant impact on the quantity and quality of plants. Application of organic fertilizers in conventional farming systems is not common and most of the nutritional need of plants supply through chemical fertilizers for short period. Excessive and unbalanced use of fertilizers in the long period, reduce crop yield and soil biological activity, accumulation of nitrates and heavy metals, and finally cause negative environmental effects and increase the cost of production. The use of bio-fertilizers and organic matter are taken into consideration to reduce the use of chemical fertilizers and increase the quality of most crops. Stability and soil fertility through the use of organic fertilizers are important due to having most of the elements required by plants and beneficial effects on physical, chemical, biological and soil fertility. Therefore, the aim of this research was to evaluate the effects of organic, biological and chemical fertilizers on quality and quantity characteristics of coriander. Materials and Methods: In order to study the effects of single and combined applications of organic, biological and chemical fertilizers on quantitative and qualitative characteristics of Coriander (Coriandrum sativum, an experiment was conducted based on a randomized complete block design with three replications and 12 treatments at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in - 2011. Treatments included: (1 mycorrhizae (Glomus mosseae (2 biosulfur (Thiobacillus sp., (3 chemical fertilizer (NPK, (4 cow manure, 5( vermin compost, 6( mycorrhizae + chemical fertilizer, 7( mycorrhizae + cow manure, 8( mycorrhizae + vermicompost, 9( biosulfur

The effect of biological fertilizers on yield, yield components and seed oil contents of three cultivars of canola (Brassica napus L.

Directory of Open Access Journals (Sweden)

A Koocheki

2016-05-01

achieve this goal is optimization and improvement of resources use efficiencies. Considering medicinal importance of savory and its role in the food and pharmaceutical industries (Omidbeigi, 2000, beside the limited nutrient resources and need to increase healthy production through using ecological inputs, this study was designed and conducted aimed to evaluate agroecological characteristics of savory as affected by the application of bio fertilizers, chemical and organic fertilizers under Mashhad conditions. Materials and methods In order to study the effects of organic, biological and chemical fertilizers on quantitative and qualitative characteristics of summer savory, a split-plot design based on RCBD with three replications was conducted during the growing season of 2012 at the Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran. Different levels of cattle manure (0 and 25 t.ha-1 were assigned to the main plots and different types of bio fertilizers (Nitroxin, containing Azotobacter sp. and Azospirillum sp., Biophosphor, containing phosphate-solubilizing bacteria (Bacillus sp. and Pseudomonas sp., Biosulfur, containing sulfur-solubilizing bacteria (Thiobacillus ssp., combination of Nitroxin+Biophosphor+ Biosulfur, vermicompost (7 t.ha-1, chemical fertilizers (NPK: 60, 60 and 70 kg.ha-1 and control (no fertilizer were used in the sub- plots. Results and discussion According to the results, all studied characteristics including plant height, lateral branches, flowering shoot yield, stem yield, percentage of essential oil and dry matter yield were affected positively by cattle manure. The highest plant height and number of lateral branches resulted from vermicompost and combination of Nitroxin+Biophosphor+Biosulfur, respectively. Biosulfur fertilizer produced the highest dry matter yield, flowering shoot yield and stem yield. Percentage of essential oil was also significantly affected by fertilizer treatments as the most