scholarly journals Optimisation of Various Physicochemical Variables Affecting Molybdenum Bioremediation Using Antarctic Bacterium, Arthrobacter sp. Strain AQ5-05

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2367
Author(s):  
Syazani Darham ◽  
Sharifah Nabilah Syed-Muhaimin ◽  
Kavilasni Subramaniam ◽  
Azham Zulkharnain ◽  
Noor Azmi Shaharuddin ◽  
...  
Keyword(s):  
Environmental Pollutants ◽  
Sodium Molybdate ◽  
Rare Metal ◽  
Industrial Applications ◽  
Microbial Reduction ◽  
Inorganic Contaminants ◽  
Optimal Temperature ◽  
High Concentration ◽  
Antarctic Bacterium ◽  
The Media

The versatility of a rare metal, molybdenum (Mo) in many industrial applications is one of the reasons why Mo is currently one of the growing environmental pollutants worldwide. Traces of inorganic contaminants, including Mo, have been discovered in Antarctica and are compromising the ecosystem. Bioremediation utilising bacteria to transform pollutants into a less toxic form is one of the approaches for solving Mo pollution. Mo reduction is a process of transforming sodium molybdate with an oxidation state of 6+ to Mo-blue, an inert version of the compound. Although there are a few Mo-reducing microbes that have been identified worldwide, only two studies were reported on the microbial reduction of Mo in Antarctica. Therefore, this study was done to assess the ability of Antarctic bacterium, Arthrobacter sp. strain AQ5-05, in reducing Mo. Optimisation of Mo reduction in Mo-supplemented media was carried out using one-factor-at-a-time (OFAT) and response surface methodology (RSM) approaches. Through OFAT, Mo was reduced optimally with substrate concentration of sucrose, ammonium sulphate, and molybdate at 1 g/L, 0.2 g/L, and 10 mM, respectively. The pH and salinity of the media were the best at 7.0 and 0.5 g/L, respectively, while the optimal temperature was at 10 °C. Further optimisation using RSM showed greater Mo-blue production in comparison to OFAT. The strain was able to stand high concentration of Mo and low temperature conditions, thus showing its potential in reducing Mo in Antarctica by employing conditions optimised by RSM.

scholarly journals Prospection of Fungal Lignocellulolytic Enzymes Produced from Jatoba (Hymenaea courbaril) and Tamarind (Tamarindus indica) Seeds: Scaling for Bioreactor and Saccharification Profile of Sugarcane Bagasse

2021 ◽  
Vol 9 (3) ◽  
pp. 533
Author(s):  
Alex Graça Contato ◽  
Tássio Brito de Oliveira ◽  
Guilherme Mauro Aranha ◽  
Emanuelle Neiverth de Freitas ◽  
Ana Claudia Vici ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Temporal Analysis ◽  
Industrial Applications ◽  
Lignocellulolytic Enzymes ◽  
Tamarindus Indica ◽  
Acetyl Xylan Esterase ◽  
Trametes Hirsuta ◽  
Hymenaea Courbaril ◽  
The Media ◽  
Main Components

The lignocellulosic biomass comprises three main components: cellulose, hemicellulose, and lignin. Degradation and conversion of these three components are attractive to biotechnology. This study aimed to prospect fungal lignocellulolytic enzymes with potential industrial applications, produced through a temporal analysis using Hymenaea courbaril and Tamarindus indica seeds as carbon sources. α-L-arabinofuranosidase, acetyl xylan esterase, endo-1,5-α-L-arabinanase, β-D-galactosidase, β-D-glucosidase, β-glucanase, β-D-xylosidase, cellobiohydrolase, endoglucanase, lichenase, mannanase, polygalacturonase, endo-1,4-β-xylanase, and xyloglucanase activities were determined. The enzymes were produced for eight filamentous fungi: Aspergillus fumigatus, Trametes hirsuta, Lasiodiplodia sp., two strains of Trichoderma longibrachiatum, Neocosmospora perseae, Fusarium sp. and Thermothelomyces thermophilus. The best producers concerning enzymatic activity were T. thermophilus and T. longibrachiatum. The optimal conditions for enzyme production were the media supplemented with tamarind seeds, under agitation, for 72 h. This analysis was essential to demonstrate that cultivation conditions, static and under agitation, exert strong influences on the production of several enzymes produced by different fungi. The kind of sugarcane, pretreatment used, microorganisms, and carbon sources proved limiting sugar profile factors.

scholarly journals Glyceraldehyde-3-Phosphate Ferredoxin Oxidoreductase from Methanococcus maripaludis

2007 ◽  
Vol 189 (20) ◽  
pp. 7281-7289 ◽  
Author(s):  
Myong-Ok Park ◽  
Taeko Mizutani ◽  
Patrik R. Jones
Keyword(s):  
Pyrococcus Furiosus ◽  
Substrate Inhibition ◽  
Physiological Role ◽  
Sodium Molybdate ◽  
Rare Metal ◽  
Growth Conditions ◽  
Defined Medium ◽  
Methanococcus Maripaludis ◽  
Ferredoxin Oxidoreductase ◽  
Gapdh Activity

ABSTRACT The genome sequence of the non-sugar-assimilating mesophile Methanococcus maripaludis contains three genes encoding enzymes: a nonphosphorylating NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPN), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR); all these enzymes are potentially capable of catalyzing glyceraldehyde-3-phosphate (G3P) metabolism. GAPOR, whose homologs have been found mainly in archaea, catalyzes the reduction of ferredoxin coupled with oxidation of G3P. GAPOR has previously been isolated and characterized only from a sugar-assimilating hyperthermophile, Pyrococcus furiosus (GAPORPf), and contains the rare metal tungsten as an irreplaceable cofactor. Active recombinant M. maripaludis GAPOR (GAPORMm) was purified from Escherichia coli grown in minimal medium containing 100 μM sodium molybdate. In contrast, GAPORMm obtained from cells grown in medium containing tungsten (W) and W and molybdenum (Mo) or in medium without added W and Mo did not display any activity. Activity and transcript analysis of putative G3P-metabolizing enzymes and corresponding genes were performed with M. maripaludis cultured under autotrophic conditions in chemically defined medium. The activity of GAPORMm was constitutive throughout the culture period and exceeded that of GAPDH at all time points. As GAPDH activity was detected in only the gluconeogenic direction and GAPN activity was completely absent, only GAPORMm catalyzes oxidation of G3P in M. maripaludis. Recombinant GAPORMm is posttranscriptionally regulated as it exhibits pronounced and irreversible substrate inhibition and is completely inhibited by 1 μM ATP. With support from flux balance analysis, it is concluded that the major physiological role of GAPORMm in M. maripaludis most likely involves only nonoptimal growth conditions.

scholarly journals Introducing a Thermo-Alkali-Stable, Metallic Ion-Tolerant Laccase Purified From White Rot Fungus Trametes hirsuta

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Si ◽  
Hongfei Ma ◽  
Yongjia Cao ◽  
Baokai Cui ◽  
Yucheng Dai
Keyword(s):  
Specific Activity ◽  
Endocrine Disrupting Chemicals ◽  
Environmental Pollutants ◽  
Fold Increase ◽  
Industrial Applications ◽  
White Rot ◽  
White Rot Fungus ◽  
Metallic Ions ◽  
Trametes Hirsuta ◽  
Ph Range

This study introduces a valuable laccase, designated ThLacc-S, purified from white rot fungus Trametes hirsuta. ThLacc-S is a monomeric protein in nature with a molecular weight of 57.0 kDa and can efficiently metabolize endocrine disrupting chemicals. The enzyme was successfully purified to homogeneity via three consecutive steps consisting of salt precipitation and column chromatography, resulting in a 20.76-fold increase in purity and 46.79% yield, with specific activity of 22.111 U/mg protein. ThLacc-S was deciphered as a novel member of the laccase family and is a rare metalloenzyme that contains cysteine, serine, histidine, and tyrosine residues in its catalytic site, and follows Michaelis-Menten kinetic behavior with a Km and a kcat/Km of 87.466 μM and 1.479 s–1μM–1, respectively. ThLacc-S exerted excellent thermo-alkali stability, since it was markedly active after a 2-h incubation at temperatures ranging from 20 to 70°C and retained more than 50% of its activity after incubation for 72 h in a broad pH range of 5.0–10.0. Enzymatic activities of ThLacc-S were enhanced and preserved when exposed to metallic ions, surfactants, and organic solvents, rendering this novel enzyme of interest as a green catalyst for versatile biotechnological and industrial applications that require these singularities of laccases, particularly biodegradation and bioremediation of environmental pollutants.

Isolation and characterization of heavy metal tolerant Gram-positive bacteria with bioremedial properties from municipal waste rich soil of Kestopur canal (Kolkata), West Bengal, India

Biologia ◽  
2012 ◽  
Vol 67 (5) ◽  
Author(s):  
Kamala Gupta ◽  
Chitrita Chatterjee ◽  
Bhaskar Gupta
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Tolerance ◽  
Environmental Pollutants ◽  
Heavy Metal Tolerance ◽  
Antibiotic Sensitivity ◽  
Bacterial Strains ◽  
High Concentration ◽  
Isolation And Characterization ◽  
Bacillus Weihenstephanensis

AbstractThe present study was conducted to determine the culturable bacterial profile from Kestopur canal (Kolkata, India) and analyze their heavy metal tolerance. In addition to daily sewage including solid and soluble wastes, a considerable load of toxic metals are released into this water body from industries, tanneries and agriculture, household as well as health sectors. Screening out microbes from such an environment was done keeping in mind their multifunctional application especially for bioremediation. Heavy metals are major environmental pollutants when present in high concentration in soil and show potential toxic effects on growth and development in plants and animals. Some edible herbs growing in the canal vicinity, and consumed by people, were found to harbour these heavy metals at sub-toxic levels. The bioconcentration factor of these plants being <1 indicates that they probably only absorb but not accumulate heavy metals. All the thirteen Grampositive bacteria isolated from these plants rhizosphere were found to tolerate high concentration of heavy metals like Co, Ni, Pb, Cr, Fe. Phylogenetic analysis of their 16S rDNA genes revealed that they belonged to one main taxonomic group — the Firmicutes. Seven of them were found to be novel with 92–95% sequence homology with known bacterial strains. Further microbiological analyses show that the alkaliphilic Bacillus weihenstephanensis strain IA1 and Exiguobacterium aestuarii strain CE1, with selective antibiotic sensitivity along with high Ni2+ and Cr6+ removal capabilities, respectively, can be prospective candidates for bioremediation.

A Novel Approach of Fabricating Monodispersed Spherical MoSiBTiC Particles for Additive Manufacturing

2021 ◽  
Author(s):  
Zhenxing Zhou ◽  
Suxia Guo ◽  
Weiwei Zhou ◽  
Naoyoki Nomura
Keyword(s):  
Additive Manufacturing ◽  
Melting Process ◽  
Industrial Applications ◽  
Elemental Distribution ◽  
Drying Process ◽  
High Concentration ◽  
Novel Approach ◽  
Composition Ratios ◽  
Mesh Structures ◽  
Ejection Method

Abstract It is very challenging to fabricate spherical refractory material powders for additive manufacturing (AM) because of their high melting points and complex compositions. In this study, a novel technique, freeze-dry pulsated orifice ejection method (FD-POEM), was developed to fabricate spherical MoSiBTiC particles without a melting process. Elemental nanopowders were dispersed in water to prepare a high-concentration slurry, which was subsequently extruded from an orifice by diaphragm vibration and frozen instantly in liquid nitrogen. After a freeze-drying process, spherical composite particles with arbitrary composition ratios were obtained. The FD-POEM particles had a narrow size range and uniform elemental distribution. Mesh structures were formed within the FD-POEM particles, which was attributed to the sublimation of ice crystals. Furthermore, owing to their spherical morphology, the FD-POEM particles had a low avalanche angle of 42.6°, exhibiting good flowability. Consequently, the combination of FD-POEM and additive manufacturing has great potential for developing complex refractory components used in industrial applications.

scholarly journals Recent advances in synthetic biosafety

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2118 ◽  
Author(s):  
Anna J. Simon ◽  
Andrew D. Ellington
Keyword(s):  
Biomedical Applications ◽  
Environmental Pollutants ◽  
Industrial Applications ◽  
Environmentally Benign ◽  
Industrial Chemicals ◽  
Recent Advances ◽  
Modern Development ◽  
Benign Synthesis ◽  
Recent Developments ◽  
Synthetic Organisms

Synthetically engineered organisms hold promise for a broad range of medical, environmental, and industrial applications. Organisms can potentially be designed, for example, for the inexpensive and environmentally benign synthesis of pharmaceuticals and industrial chemicals, for the cleanup of environmental pollutants, and potentially even for biomedical applications such as the targeting of specific diseases or tissues. However, the use of synthetically engineered organisms comes with several reasonable safety concerns, one of which is that the organisms or their genes could escape their intended habitats and cause environmental disruption. Here we review key recent developments in this emerging field of synthetic biocontainment and discuss further developments that might be necessary for the widespread use of synthetic organisms. Specifically, we discuss the history and modern development of three strategies for the containment of synthetic microbes: addiction to an exogenously supplied ligand; self-killing outside of a designated environment; and self-destroying encoded DNA circuitry outside of a designated environment.

scholarly journals Effect of Dissolved Organic Matter on Agglomeration and Removal of CuO Nanoparticles by Coagulation

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 455 ◽  
Author(s):  
Rizwan Khan ◽  
Muhammad Ali Inam ◽  
Muhammad Akram ◽  
Ahmed Uddin ◽  
Sarfaraz Khan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Industrial Applications ◽  
Water Bodies ◽  
Hydrodynamic Diameter ◽  
Excess Charge ◽  
High Concentration ◽  
Potential Threat ◽  
Cuo Nps ◽  
Coagulation Process

Engineered nanomaterials (ENMs), such as copper oxide nanoparticles (CuO NPs), are emerging as pollutants extensively used in many commercial and industrial applications, thus raising environmental concerns due to their release into water bodies. It is, therefore, essential to remove these pollutants from water bodies in order to minimize the potential threat to the aquatic environment and human health. The objective of this study was to investigate the removal of CuO NPs from waters by the coagulation process. This study also explored the efficiency of coagulation to remove hydrophobic/hydrophilic dissolved organic matter (DOM) and turbidity with varying polyaluminum chloride (PACl) doses. According to the results, a high concentration of DOM affects both the CuO NPs zeta potential and hydrodynamic diameter, thereby decreasing the agglomeration behavior. At effective coagulation zone (ECR), high removal of CuO NPs (>95%) was observed for all studied waters (hydrophobic and hydrophilic waters), above ECR excess charge induced by coagulant restabilized particles in solution. Furthermore, waters containing hydrophobic DOM and those with high UV254nm values needed more coagulant dose than hydrophilic waters to obtain similar CuO NP removals. The primary mechanism involved in CuO NPs removal might be charge neutralization. These findings suggest that PACl is an effective coagulant in the removal of CuO NPs; however, water characteristics are an influencing factor on the removal performance of ENMs during the coagulation process.

Inhibition of prostaglandin effects by ouabain in the canine vascular tissue

1969 ◽  
Vol 47 (10) ◽  
pp. 871-879 ◽  
Author(s):  
D. Kadar ◽  
F. A. Sunahara
Keyword(s):  
Vascular Tissue ◽  
Prostaglandin E ◽  
High Concentration ◽  
Low Concentration ◽  
Mesenteric Vein ◽  
Dependent Atpase ◽  
Prostaglandin F ◽  
The Media ◽  
Spontaneous Contractions ◽  
Dose Dependent

The effects of prostaglandins on the isolated mesenteric vein and artery of the dog were investigated. Prostaglandin E1 (PGE1) inhibited spontaneous contractions of the tissue whereas prostaglandin F1α (PGF1α) and prostaglandin F2α (PGF2α) stimulated them. The effects of prostaglandins were not influenced by pretreatment with atropine, phenoxybenzamine, propranolol, or tetrodotoxin. The norepinephrine-induced contractions were inhibited by PGE1 and enhanced by PGF1α and PGF2α Both these contrasting effects were enhanced in a low concentration of K+ (1.2 mM) and diminished when the media contained K+ in high concentration (23.2 mM). Pretreatment of the tissue with ouabain in sufficiently high concentration (1.5 × 10−5 M) produced an initial contracture followed by relaxation. PGE1 and PGF1α had no effect on the ouabain-treated tissue but PGF2α still induced dose-dependent contractions. In the ouabain-treated tissue the effects of PGE1 and PGF1α on the norepinephrine-induced contraction were also absent. From these experiments it is concluded that the transport enzyme (Na+ + K+)-dependent ATPase is necessary for PGE1 and PGF1α to elicit their action on vascular tissue. The PGF2α effect is probably mediated by an enzyme which is not sensitive to ouabain.

Properties of Phytase from Aspergillus oryzae093

2010 ◽  
Vol 113-116 ◽  
pp. 1833-1836
Author(s):  
Na Zhang ◽  
Xiao Mei Li ◽  
Qing Qi Guo
Keyword(s):  
Optimal Condition ◽  
Heat Stability ◽  
Phytase Activity ◽  
Enzyme Properties ◽  
Optimal Temperature ◽  
High Concentration ◽  
Sodium Phytate ◽  
Low Concentration ◽  
Food And Feed ◽  
Phytate Hydrolysis

Optimal condition, stability and Km of phytase which was from Aspergillus oryzae093 were studied. The optimal temperature and pH for sodium-phytate hydrolysis by Aspergillus oryzae093 phytase is 50°C and 5.5 respectively. Phytase has better heat stability as temperature below 45°C. The phytase activity remained 90% when pH is 5.0 to 6.0. Low concentration Fe2+ and Mg2+ can promote phytase activity, while Cu2+, Mn2+, Fe3+, Al3+ or high concentration Fe2+ and Mg2+ can inhibite the activity of phytase. The Km is about 4.8×10-5 mol•L-1 when sodium phytate as substrate. The enzyme properties of Aspergillus oryzae093 phytase make it could apply to food and feed to reduce the phosphorus exhausted to environment.

scholarly journals Comparative molecular studies of halophilic bacteria from saline water and soil in the Saudi environment

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Mohamed Ahmed ◽  
Md. Mohibul Alam Khan ◽  
Saleh M. S. Al-Garni ◽  
Roop Singh Bora ◽  
Saleh A. Kabli
Keyword(s):  
Red Sea ◽  
Saline Water ◽  
Halophilic Bacteria ◽  
16S Rrna Gene Sequencing ◽  
Industrial Applications ◽  
Rrna Gene ◽  
Bacterial Isolates ◽  
High Concentration ◽  
Biochemical Tests ◽  
Water And Soil Samples

Halophilic bacteria are a microorganism that grows optimally in the presence of the very high concentration of sodium chloride. Halophiles are vital sources of various enzymes including hydrolases, which are very stable and catalytically highly efficient at high salt concentration and other extreme conditions such as high temperature, pH and presence of organic solvents.  Several hydrolases such as amylases, proteases, and lipases have been obtained from halophilic bacteria and are commonly used for various industrial applications. We initiated a screening project to isolate and characterize the halophilic bacteria from the Red Sea, which is one of the saltiest bodies of water in the world. Water and soil samples, collected from the Red Sea coast, Jeddah, Saudi Arabia, were screened for isolation of halophilic bacteria. Ten bacterial isolates were obtained, which were characterized by biochemical tests and 16S rRNA gene sequencing. Hydrolase producing bacteria among the isolates were screened by plate assay on starch and gelatin agar plates for amylase and protease, respectively.  Two bacterial isolates i.e Bacillus haynesii and Enterobacter cloacae subsp. were found to possess significant amylase and protease activity. Further characterization of both the strains is in progress.

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