bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated system for the biological solubilization and precipitation of heavy metals for the remediation of contaminated media
Authors: Cabrera Gema , Gómez Jose M , Cantero Domingo 
Published: February 2008

AbstractBACKGROUND The work described here concerns a laboratory‐scale investigation into the remediation of sand artificially contaminated with a mixture of heavy metals using a two‐step process: the first step involved solubilization of the sand contaminants with sulfur‐oxidizing bacteria and the second step consisted of the precipitation of heavy metals from solution with sulfate‐reducing bacteria. Initially it was necessary to study the immobilization of sulfur‐oxidizing bacteria (Acidithiobacillus ferrooxidans and At. thiooxidans) on polyurethane foam. A support colonized by At. thiooxidans was selected and was added to a reactor for the continuous system. The acidic medium generated in this reactor was added to a column along with 50 g of artificially contaminated sand (85 mg Cr(III), 20 mg Ni(II) and 200 mg Zn(II)). The effluent from this step was collected in a reservoir tank and H2S, which was biologically generated by sulfate‐reducing bacteria (Desulfovibrio sp.), was added in order to carry out the precipitation of metals.RESULTS: When 2.4 L of acid medium was passed through the column, it was observed that 14.6% of Cr(III), 26.7% of Ni(II) and 90.5% of Zn(II) were solubilized. The leachate (2.4 L) was treated with 2.2 L of reducing medium and 2.2% Cr(III), 54% Ni(II) and 28% Zn(II) of metals present in leachate were precipitated.CONCLUSION: The proposed process is therefore suitable for the extraction and deposition of heavy metals from contaminated media and several design changes are currently being made in order to improve and optimize this remediation system. Copyright © 2008 Society of Chemical Industry
Biosorption potential of dried Penicillium restrictum for Reactive Orange 122: isotherm, kinetic and thermodynamic studies
Authors: Ilhan Semra , Iscen Cansu Filik , Caner Necmettin , Kiran Ismail 
Published: February 2008

AbstractBACKGROUND: This paper evaluates the biosorption of Reactive Orange 122 dye (RO 122) by dried Penicillium restrictum cells. The aim was to determine the pH, contact time, temperature and dye concentration for the applicability of biomass as an alternative biosorbent for the removal of RO 122.RESULTS: Optimum initial pH and equilibrium time for RO 122 were determined as 1.0 and 75 min at 25 °C, respectively. The maximum biosorption capacity (qmax) of biomass obtained from the Langmuir fit was 180.7, 190.1 and 219.8 mg g−1 biomass at 25, 40 and 50 °C, respectively. Both Langmuir and Freundlich isotherm models were fitted to the experimental data at constant temperatures of 25, 40 and 50 °C. The biosorption process was found to obey a pseudo‐second‐order kinetic model and was favourable at high temperatures.CONCLUSIONS: The biomass could be an alternative biosorbent to RO 122 dye removal because of having advantages of being easily cultivable, its low cost, high biosorption capacity with low biomass dosage (0.4 g dm−3) and reasonably rapid biosorption rate. Copyright © 2008 Society of Chemical Industry
Comparison of thermo‐oxidative treatments for the anaerobic digestion of sewage sludge
Authors: Takashima M , Tanaka Y 
Published: February 2008

AbstractBACKGROUND: In this study, various thermo‐oxidative treatments were examined and compared with the aim of overcoming the disadvantages of thermal treatment and enhancing the anaerobic digestion of sewage sludge.RESULTS: Oxygen, hydrogen peroxide and ozone were selected as oxidant, accompanied with the addition of either acid (HCl) or alkali (Na2CO3) for oxygen. The temperature and duration were fixed at 170 °C and 1 h, respectively. Anaerobically digested sludge was used as the substrate, to see the effects on the refractory part of sewage sludge. A batch methanogenesis test using 120 mL serum bottles was run at 35 °C for 20 days, and methane production, solids reduction, dewaterability and color intensity were measured. As the strength of the oxidants was increased, methane production tended to decrease, whereas solids reduction was increased. The dewaterability of the sludges and the color in the filtrates became worse for thermo‐oxidative treatment with oxygen and alkali. On the other hand, the dewaterability was improved significantly and color generation was restricted the most for the thermo‐oxidative treatment with oxygen and acid.CONCLUSION: Lowering the pH of thermo‐oxidative treatment is advantageous with respect to the dewaterability and color generation of digested sludge. Based on evaluation of the overall performance, thermo‐oxidative treatment with acid is considered the best among the thermo‐oxidative treatments examined. Copyright © 2008 Society of Chemical Industry
Optimization of medium and process parameters for a constitutive α‐amylase production from a catabolite derepressed Bacillus subtilis KCC103
Authors: Rajagopalan Gobinath , Krishnan Chandraraj 
Published: February 2008

AbstractBACKGROUND: In Bacillus subtilis KCC103 α‐amylase is hyper‐produced and not catabolite repressed by glucose. Various sugars, raw starches and nitrogen sources were tested for their repression effect on α‐amylase synthesis. Enhancement of α‐amylase production by supplementing micronutrients and surfactants was studied. Using optimized medium, process parameters were optimized for improved α‐amylase production.RESULTS: α‐Amylase was produced from KCC103 utilizing simple sugars indicating the absence of catabolite repression. Raw potato and yeast extract were best carbon and nitrogen sources for α‐amylase production. α‐Amylase synthesis was enhanced by micronutrients cysteine, thiamine, Mg2+ and SDS. Maximum α‐amylase (394 IU mL−1) was produced in the optimized medium consisting of (in g L−1) raw potato (30.0), yeast extract (20.0), cysteine (0.3), thiamine (0.2), SDS (0.2) and MgSO4 (0.5 mmol L−1) at 36–48 h under optimal conditions (pH 7.0, 37 °C, 200 rpm). The α‐amylase production was further enhanced to 537.7 IU mL−1 with shorter time (15–18 h) in a bioreactor with optimized agitation rate of 700 rpm at 30% dissolved oxygen.CONCLUSION: Since there was no carbon catabolite repression of α‐amylase synthesis, sugar mixture from various agro‐residues hydrolysates could be utilized for α‐amylase production. The study showed the feasibility of utilization of raw potato for α‐amylase production from the KCC103, which would lead to a significant reduction in process cost. Copyright © 2008 Society of Chemical Industry
Strategies of pH control and glucose‐fed batch fermentation for production of succinic acid by Actinobacillus succinogenes CGMCC1593
Authors: Liu Yu‐Peng , Zheng Pu , Sun Zhi‐Hao , Ni Ye , Dong Jin‐Jun , Wei Ping 
Published: February 2008

AbstractBACKGROUND: Succinic acid is an important precursor of numerous products, including pharmaceuticals, feed additives, green solvents, and biodegradable polymers. In this work, strategies of pH control and glucose‐fed batch fermentation for producing succinic acid using Actinobacillus succinogenes CGMCC1593 were carefully optimized.RESULTS: The production of succinic acid was stable within the pH range 6.0–7.2. Both cell growth and succinic acid production were inhibited by high concentrations of sodium and calcium ions, while there was no significant inhibition by magnesium ions. With an initial glucose concentration of 25 g L−1, and glucose concentration was maintained between 10 and 15 g L−1 during the course of fed batch fermentation, succinic acid concentration, productivity and yield were 60.2 g L−1, 1.3 g L−1 h−1 and 75.1%, respectively.CONCLUSION: Of all the neutralization reagents used for pH control of A. succinogenes CGMCC1593, solid MgCO3 was the most satisfactory. With increase of initial glucose concentration, the time course showed a longer growth lag period and the maximum biomass declined, while more carbon was diverted to succinate synthesis. The results obtained in this study should be helpful for the design of a highly efficient succinic acid production process. Copyright © 2008 Society of Chemical Industry
Modulated gluconic acid production from immobilized cells of Aspergillus niger ORS‐4.410 utilizing grape must
Authors: Singh Om V 
Published: February 2008

AbstractBACKGROUND: Gluconic acid (GA) production by immobilized cells of mutant Aspergillus niger ORS‐4.410 on polyurethane sponge (PUS) and calcium‐alginate (Ca‐alginate) was evaluated in repeated batches of solid state surface fermentation (SSF) and submerged fermentation (SmF) conditions, respectively, utilizing rectified grape must as carbon source.RESULTS: The passive immobilization of cells in fermentation medium solid support of having 0.4 cm3 cube size, 4% spore suspension, 0.6 g inoculum of PUS immobilized cells at 32 °C and 2.0 L min−1 resulted in the maximum GA production (88.16 g L−1) with a 92.8% yield, while the Ca‐alginate matrix with a 0.5 cm diameter bead size, 2–3% spore suspension, 15 g inoculum at 34 °C and 150 rpm agitation speed revealed 67.19 g L−1 GA with a 85.2% yield. Repeated use of PUS showed higher levels of GA (110.94 g L−1) in the third–fourth fermentation cycles with 95–98% yield and 22.50 g L−1 d−1 productivity under SSF that was 2.5‐fold higher than the productivity obtained from a typical fermentation cycle, and 54% greater than the productivity obtained with repetitive use of Ca‐alginate immobilized cells of A. niger under SmF.CONCLUSION: Using immobilized cells of A. niger in PUS, the rectified form of grape must can be utilized for GA production as an alternative source of carbohydrate by replacing the conventional fermentation conditions. Copyright © 2008 Society of Chemical Industry
Simultaneous phenol removal and biological reduction of hexavalent chromium in a packed‐bed reactor
Authors: Tziotzios George , Dermou Eftychia , Politi Dorothea , Vayenas Dimitris V 
Published: February 2008

AbstractBACKGROUND: Phenol and hexavalent chromium are considered industrial pollutants that pose severe threats to human health and the environment. The two pollutants can be found together in aquatic environments originating from mixed discharges of many industrial processes, or from a single industry discharge. The main objective of this work was to study the feasibility of using phenol as an electron donor for Cr(VI) reduction, thus achieving the simultaneous biological removal/reduction of the two pollutants in a packed‐bed reactor.RESULTS: A pilot‐scale packed‐bed reactor was used to estimate phenol removal with simultaneous Cr(VI) reduction through biological mechanisms, using a new mixed bacterial culture originated from Cr(VI)‐reducing and phenol‐degrading bacteria, operated in draw–fill mode with recirculation. Experiments were performed for feed Cr(VI) concentration of about 5.5 mg L−1, while phenol concentration ranged from 350 to 1500 mg L−1. The maximum reduction/removal rates achieved were 0.062 g Cr(VI) L−1 d−1 and 3.574 g phenol L−1 d−1, for a phenol concentration of 500 mg L−1.CONCLUSION: Phenol removal with simultaneous biological Cr(VI) reduction is feasible in a packed‐bed attached growth bioreactor. Phenol was found to inhibit Cr(VI) reduction, while phenol removal was rather unaffected by Cr(VI) concentration increase. However, the recorded removal rates of phenol and Cr(VI) were found to be much lower than those obtained from previous research, where the two pollutants were examined separately. Copyright © 2008 Society of Chemical Industry
Characterization of a novel glutamate decarboxylase from Streptococcus salivarius ssp. thermophilus Y2
Authors: Yang Sheng‐Yuan , Lin Qian , Lu Zhao‐Xin , Lü Feng‐Xia , Bie Xiao‐Mei , Zou Xiao‐Kui , Sun Li‐Jun 
Published: February 2008

AbstractBACKGROUND: γ‐Aminobutyric acid with several well‐known physiological functions is biosynthesized via the irreversible α‐decarboxylation of L‐glutamate catalysed by glutamate decarboxylase (GAD). Although Streptococcus salivarius ssp. thermophilus has been widely applied to the dairy, the characterization of its GAD has not been reported. In this paper, the purification and the characterization of S. salivarius ssp. thermophilus GAD were investigated.RESULTS: GAD was purified 22‐fold from crude protein extracts with a yield of 7.8% in five steps. The final preparation gave a single band on SDS‐PAGE. The molecular weight of GAD determined by SDS‐PAGE and gel filtration was 46.9 kDa and 103.6 kDa, respectively, indicating that the enzyme exists as a dimmer of homological subunits. The optimum temperature and pH of GAD was 55 °C and pH 4.0, respectively. The enzyme reacted only with L‐glutamate among 19 α‐amino acids with apparent Km at 2.3 mmol L−1 and did not react with D‐glutamic acid. Activity of the enzyme could significantly be activated by 5 mmol L−1 of BaCl2 and inhibited by FeSO4, ZnSO4, CuSO4, MnSO4, Na2SO4, AgNO3, CoCl2, LiCl and KCl, respectively. The N‐terminal amino acid sequence of GAD was NH2‐MNEKLFREI.CONCLUSION: Both the characterization and the deduced amino sequence (ABI31651) showed the purified enzyme was a novel GAD. Copyright © 2008 Society of Chemical Industry
Biological Cr(VI) reduction in a trickling filter under continuous operation with recirculation
Authors: Dermou Eftychia , Vayenas Dimitris V 
Published: February 2008

AbstractBACKGROUND: Hexavalent chromium (Cr(VI)) is toxic to humans, animals and plants. Conventional treatment technologies reduce Cr(VI) to the less toxic and mobile Cr(III), but these methods are usually expensive and generate secondary waste. Microbial Cr(VI) reduction has recently gained attention as a detoxification process, since it enables Cr(VI) reduction through relatively cheap and simple methods. The aim of this work was to investigate the mechanism and the performance of biological Cr(VI) reduction using mixed cultures originated from industrial sludge under continuous operation with recirculation in a pilot‐scale trickling filter.RESULTS: Biological Cr(VI) reduction was studied using a pilot‐scale trickling filter filled with plastic media under continuous operation with recirculation and the use of indigenous bacterial population. The effect of the organic carbon (electron donor) concentration was examined for constant Cr(VI) influent concentration at about 5.5 mg L−1 and volumetric flow rates ranging from 60 to 900 mL min−1. The highest reduction rate achieved was 1117 g Cr(VI) m−2 d−1 for a volumetric flow rate of 900 mL min−1. The system's reduction capacity was significantly affected by chromate loadings, resulting in frequent backwashing of the filter. The determination of the reduction mechanism was also studied using batch cultures of free suspended cells and culture supernatant.CONCLUSION: The high reduction rates combined with the low operating cost indicate that the above technology can be a viable solution for the treatment of industrial chromate effluents. Copyright © 2008 Society of Chemical Industry
Use of ionic liquids for the efficient utilization of lignocellulosic materials
Authors: Zhu Shengdong 
Published: February 2008

AbstractLignocellulosic materials are the most abundant renewable resource in the world and their efficient utilization provides a practical route to maintain social sustainable development. Application of ionic liquids has opened new avenues for the efficient utilization of lignocellulosic materials in such areas as fractionation, preparation of cellulose composites and derivatives, analysis, and removal of pollutants. However, there are still many challenges in putting these potential applications into practical use, for example, the high price of ionic liquids and lack of basic physico‐chemical and toxicological data. Further research and financial support are required to address such challenges. Copyright © 2008 Society of Chemical Industry
Radiosynthesis of novel 18F‐labelled derivatives of indiplon as potential GABAA receptor imaging tracers for PET
Authors: Fischer Steffen , Hiller Achim , Scheunemann Matthias , Deuther‐Conrad Winnie , Hoepping Alexander , Diekers Michael , Wegner Florian , Brust Peter , Steinbach Jörg 
Published: February 2008

AbstractThe involvement of gamma amino butyric acid (GABA) receptors in a variety of neurological and psychiatric diseases has promoted the development and use of radiolabelled benzodiazepines (BZ) for brain imaging by PET. However, these radioligands are unable to distinguish between the various subtypes of GABAA receptors. Novel non‐BZ such as the pyrazolo‐pyrimidine indiplon proved to be selective for the α1‐subunit of the GABAA receptor. Here, we describe the syntheses of four novel 18F‐labelled indiplon derivatives. Radiosyntheses were performed via n.c.a. 18F‐nucleophilic substitution starting from the tosyl, bromo, and 4‐nitrobenzoyl precursors to obtain fluorine substituted N‐alkylamide side chain derivatives of indiplon, followed by multistep purification using semi‐preparative high‐performance liquid chromatography and solid phase extraction. Tosyl and bromo precursors were converted into 18F‐labelled indiplon derivatives with good and reproducible radiochemical yield (RCY) (35–70%, decay corrected), high radiochemical purity (≥98.5%), and high specific activity ( > 150 GBq/µmol). By contrast, a low RCY (5–10%) and specific activity (10–15 GBq/µmol) were achieved for the 4‐nitrobenzoyl precursor. Copyright © 2008 John Wiley & Sons, Ltd.
Experimental micromechanics of the cement–bone interface
Authors: Mann Kenneth A. , Miller Mark A. , Cleary Richard J. , Janssen Dennis , Verdonschot Nico 
Published: February 2008

AbstractDespite the widespread use of cement as a means of fixation of implants to bone, surprisingly little is known about the micromechanical behavior in terms of the local interfacial motion. In this work, we utilized digital image correlation techniques to quantify the micromechanics of the cement–bone interface of laboratory‐prepared cemented total hip replacements subjected to nondestructive, quasistatic tensile and compressive loading. Upon loading, the majority of the displacement response localized at the contact interface region between cement and bone. The contact interface was more compliant (p = 0.0001) in tension (0.0067 ± 0.0039 mm/MPa) than compression (0.0051 ± 0.0031 mm/MPa), and substantial hysteresis occurred due to sliding contact between cement and bone. The tensile strength of the cement–bone interface was inversely proportional to the compliance of the interface and proportional to the cement/bone contact area. When loaded beyond the ultimate strength, the strain localization process continued at the contact interface between cement and bone with microcracking (damage) to both. More overall damage occurred to the cement than to the bone. The opening and closing at the contact interface from loading could serve as a conduit for submicron size particles. In addition, the cement mantle is not mechanically supported by surrounding bone as optimally as is commonly assumed. Both effects may influence the longevity of the reconstruction and could be considered in preclinical tests. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:872–879, 2008
Full‐length bovine spp24 [spp24 (24‐203)] inhibits BMP‐2 induced bone formation
Authors: Sintuu Chananit , Murray Samuel S. , Behnam Keyvan , Simon Robert , Jawien Janusz , Silva Jose Denison Prado , Duarte Maria Eugenia Leite , Brochmann Elsa J. 
Published: February 2008

AbstractSecreted phosphoprotein 24 kDa (spp24) is a bone matrix protein. It contains a TGF‐β receptor II homology 1 (TRH1) domain. A cyclic, synthetic 19 amino acid peptide (bone morphogenetic protein binding peptide or BBP) based on the sequence of the TRH1 domain enhances BMP‐2 induced osteogenesis. Many observations suggest that different size forms of this protein have very different effects (inhibiting or enhancing) on BMP‐2 induced osteogenesis. Using the stable recombinant Met(His)6‐tagged secretory form of full‐length (fl) bovine spp24 [Met(His)6‐spp24 (residues 24–203)] and transgenic (TG) mice expressing fl bovine spp24 (residues 1–203), we have demonstrated that spp24 inhibits BMP‐2 induced bone formation. The effects of Met(His)6‐spp24 (24–203) were determined in the ectopic bone‐forming bioassay in male mice. Implantation of 5 µg of BMP‐2 stimulated bone formation, assessed densitometrically as bone area and mineral content. When Met(His)6‐spp24 (24–203) was implanted with BMP‐2, it elicited a dose‐dependent decrease in BMP‐2‐medicated ectopic bone formation. When added at a 50‐fold excess (w/w), Met(His)6‐spp24 (24–203) completely ablated the effects of BMP‐2, while addition of a 10‐fold excess had no effect. Constitutive expression of fl bovine spp24 (1–203) under the control of the osteocalcin promoter in TG female mice reduced femoral and vertebral bone mineral density at 3 months of age and reduced femoral BMD at 8 months of age, but had no effects in male mice, which can exhibit less osteocalcin‐promoter driven gene transcription than females. Histomorphometric analysis demonstrated that bone volume and trabecular thickness were lower in TG female mice at 3 months of age than in sex‐ and age‐matched wild type (WT) controls. Thus, fl spp24 and its secretory isoform (Met(His)6‐spp24 [24–203]), which contain a BMP‐binding or TRH1 motif, inhibit ectopic bone formation in male mice and adversely affects BMD and histological parameters related to bone mass and formation in female mice expressing the human transgene. Under these conditions, fl spp24 acts as a BMP antagonist in vivo. © 2008 Orthopaedic Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:753–758, 2008
SERS characterization of metallic silver nanoparticle self‐assembly within thin films
Authors: Whitcomb D. R. , Stwertka B. J. , Chen S. , Cowdery‐Corvan P. J. 
Published: February 2008

AbstractClusters of silver nanoparticles are generated by the thermally initiated reduction of silver carboxylates (long‐chain fatty acids) in the thin polymer films. The size, shape, and aggregation of these nanoparticles are affected by the reduction reaction in the presence of capping agents. In order to understand the mechanism(s) controlling the silver structure formation, it is essential to understand the surface coordination chemistry occurring during this process. We now report the first application of surface‐enhanced Raman spectroscopy (SERS) to directly characterize adsorbates on the surfaces of silver nanoparticles within a thin film imaging construction containing multiple components. In addition, SERS investigation of model silver substrates was used to confirm the identify of specific adsorbates of silver complexes. This is a powerful tool for revealing the chemistry involved with the control of silver nanoparticle aggregation during thermally induced metallic silver formation within thin films. Both the catechol‐reducing agent and the phthalazinone (PAZ) particle aggregation agent are observed on the metallic silver surface at the initial particle formation and during its crystal growth. However, careful attention to excitation wavelength is required in order to observe all the surface species. PAZ appears to be more effective at stabilizing individual silver particles than other aggregation agents investigated. An understanding of the roles of the aggregation/reducing agents in the growth and aggregation of silver nanoparticles is important for preparing different types of silver particles for specific applications including silver‐based thermal imaging systems. Copyright © 2008 John Wiley & Sons, Ltd.