An artificial neural network (ANN) model was developed to simulate the biodegradation of herbicide glyphosate [2-(Phosphonomethylamino) acetic acid] in a solution with varying parameters pH, inoculum size and initial glyphosate concentration. The predictive ability of ANN model was also compared with Monod model. The result showed that ANN model was able to accurately predict the experimental results. A low ratio of self-inhibition and half saturation constants of Haldane equations (< 8) exhibited the inhibitory effect of glyphosate on bacteria growth. The value of K(i)/K(s) increased when the mixed inoculum size was increased from 10(4) to 10(6) bacteria/mL. It was found that the percentage of glyphosate degradation reached a maximum value of 99% at an optimum pH 6-7 while for pH values higher than 9 or lower than 4, no degradation was observed.
In this study, the performance of glyphosate removal in an electrocoagulation batch with two electrodes formed by the same metal type, consisting of aluminum, iron, steel and copper have been compared. The aim of this study intends to remove glyphosate from an aqueous solution by an electrocoagulation process using metal electrode plates, which involves electrogeneration of metal cations as coagulant agents. The production of metal cations showed an ability to bind together to form aggregates of flocs composed of a combination of glyphosate and metal oxide. Electrocoagulation using aluminum electrodes indicated a high percentage removal of glyphosate, 94.25%; followed by iron electrodes, 88.37%; steel electrodes, 62.82%; and copper electrodes, 46.69%. The treated aqueous solution was then analyzed by Fourier Transform Infrared Spectroscopy. Percentages of Carbon, Hydrogen, Nitrogen, Sulfur remaining in the treated aqueous solution after the electrocoagulation process have been determined. The treated water and sludge were characterized and the mechanism of the overall process was concluded as an outcome. An X-Ray Diffraction analysis of dried sludge confirmed that new polymeric compounds were formed during the treatment. The sludge composed of new compounds were also verified the removals. This study revealed that an electrocoagulation process using metal electrodes is reliable and efficient.
Two optimization strategies, codon usage modification and glycine supplementation, were adopted to improve the extracellular production of Bacillus sp. NR5 UPM β-cyclodextrin glycosyltransferase (CGT-BS) in recombinant Escherichia coli. Several rare codons were eliminated and replaced with the ones favored by E. coli cells, resulting in an increased codon adaptation index (CAI) from 0.67 to 0.78. The cultivation of the codon modified recombinant E. coli following optimization of glycine supplementation enhanced the secretion of β-CGTase activity up to 2.2-fold at 12 h of cultivation as compared to the control. β-CGTase secreted into the culture medium by the transformant reached 65.524 U/mL at post-induction temperature of 37 °C with addition of 1.2 mM glycine and induced at 2 h of cultivation. A 20.1-fold purity of the recombinant β-CGTase was obtained when purified through a combination of diafiltration and nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography. This combined strategy doubled the extracellular β-CGTase production when compared to the single approach, hence offering the potential of enhancing the expression of extracellular enzymes, particularly β-CGTase by the recombinant E. coli.
This study investigates adsorption-desorption and the leaching potential of glyphosate and aminomethylphosphonic acid (AMPA) in control and amended-addition of cow dung or rice husk ash-acidic Malaysian soil with high oxide mineral content. The addition of cow dung or rice husk ash increased the adsorptive removal of AMPA. The isotherm data of glyphosate and AMPA best fitted the Freundlich model. The constant Kf for glyphosate was high in the control soil (544.873 mg g-1) followed by soil with cow dung (482.451 mg g-1) then soil with rice husk ash (418.539 mg g-1). However, for AMPA, soil with cow dung was high (166.636 mg g-1) followed by soil with rice husk ash (137.570 mg g-1) then the control soil (48.446 mg g-1). The 1/n values for both glyphosate and AMPA adsorptions were
Pesticides are developed with carriers to improve their physicochemical properties and, accordingly, the bioefficacy of the applied formulation. For foliar-applied herbicide, generally less than 0.1% of the active ingredient reaching the target site could reduce pesticide performance. Recently, a carrier of nanoemulsion consisting of oil, surfactant and water, with a particle size of less than 200 nm, has been shown to enhance drug permeability for skin penetration in pharmaceutical delivery systems. In the present work, the aim was to formulate a water-soluble herbicide, glyphosate isopropylamine (IPA), using a green nanoemulsion system for a biological activity study against the weeds creeping foxglove, slender button weed and buffalo grass.
Cancer is the second leading cause of death-1 in 6 deaths globally is due to cancer. Cancer metabolism is a complex and one of the most actively researched area in cancer biology. Metabolic reprogramming in cancer cells entails activities that involve several enzymes and metabolites to convert nutrient into building blocks that alter energy metabolism to fuel rapid cell division. Metabolic dependencies in cancer generate signature metabolites that have key regulatory roles in tumorigenesis. In this minireview, we highlight recent advances in the popular methods ingrained in biochemistry research such as stable and flux isotope analysis, as well as radioisotope labeling, which are valuable in elucidating cancer metabolites. These methods together with analytical tools such as chromatography, nuclear magnetic resonance spectroscopy and mass spectrometry have helped to bring about exploratory work in understanding the role of important as well as obscure metabolites in cancer cells. Information obtained from these analyses significantly contribute in the diagnosis and prognosis of tumors leading to potential therapeutic targets for cancer therapy.
Cutinase catalyzes the hydrolysis of water-soluble esters and long-chain triglycerides and belongs to the family of serine hydrolases. The enzyme is thought to represent an evolutionary link between the esterase and lipase families and has potential applications in a wide range of industrial hydrolytic processes, for which an understanding of the molecular basis of its substrate specificity is critical. Glomerella cingulata cutinase has been cloned and the protein has been overexpressed in Escherichia coli, purified and subsequently crystallized in a wide range of different crystal forms in the presence and absence of inhibitors. The best crystals are those of the apo cutinase, which diffract to beyond 1.6 A resolution and belong to space group P4(1)2(1)2 or P4(3)2(1)2. Crystals of cutinase with the inhibitors PETFP or E600 belong to space groups P2(1)2(1)2(1) and P2(1), respectively, and diffract to approximately 2.5 A resolution. All of the crystals are suitable for structural studies, which are currently ongoing.
A series of ternary copper(II)-1,10-phenanthroline complexes with glycine and methylated glycine derivatives, [Cu(phen)(aa)(H(2)O)]NO(3)·xH(2)O 1-4 (amino acid (aa): glycine (gly), 1; DL: -alanine (DL: -ala), 2; 2,2-dimethylglycine (C-dmg), 3; sarcosine (sar), 4), were synthesized and characterized by FTIR, elemental analysis, electrospray ionization-mass spectra (ESI-MS), UV-visible spectroscopy and molar conductivity measurement. The determined X-ray crystallographic structures of 2 and 3 show each to consist of distorted square pyramidal [Cu(phen)(aa)(H(2)O)](+) cation, a nitrate counter anion, and with or without lattice water, similar to previously reported structure of [Cu(phen)(gly)(H(2)O)]NO(3)·1½H(2)O. It is found that 1-4 exist as 1:1 electrolytes in aqueous solution, and the cationic copper(II) complexes are at least stable up to 24 h. Positive-ion ESI-MS spectra show existence of only undissociated [Cu(phen)(aa)](+) species. Electron paramagnetic resonance, gel electrophoresis, fluorescence quenching, and restriction enzyme inhibition assay were used to study the binding interaction, binding affinity and selectivity of these complexes for various types of B-form DNA duplexes and G-quadruplex. All complexes can bind selectively to DNA by intercalation and electrostatic forces, and inhibit topoisomerase I. The effect of the methyl substituents of the coordinated amino acid in the above complexes on these biological properties are presented and discussed. The IC(50) values (24 h) of 1-4 for nasopharyngeal cancer cell line HK1 are in the range 2.2-5.2 μM while the corresponding values for normal cell line NP69 are greater than 13.0 μM. All complexes, at 5 μM, induced 41-60 % apoptotic cell death in HK1 cells but no significant cell death in NP69 cells.
A dynamic supported liquid membrane tip extraction (SLMTE) procedure for the effective extraction and preconcentration of glyphosate (GLYP) and its metabolite aminomethylphosphonic acid (AMPA) in water has been investigated. The SLMTE procedure was performed in a semi-automated dynamic mode and demonstrated a greater performance against a static extraction. Several important extraction parameters such as donor phase pH, cationic carrier concentration, type of membrane solvent, type of acceptor stripping phase, agitation and extraction time were comprehensively optimized. A solution of Aliquat-336, a cationic carrier, in dihexyl ether was selected as the supported liquid incorporated into the membrane phase. Quantification of GLYP and AMPA was carried out using capillary electrophoresis with contactless conductivity detection. An electrolyte solution consisting of 12 mM histidine (His), 8 mM 2-(N-morpholino)ethanesulfonic acid (MES), 75 microM cetyltrimethylammonium bromide (CTAB), 3% methanol, pH 6.3, was used as running buffer. Under the optimum extraction conditions, the method showed good linearity in the range of 0.01-200 microg/L (GLYP) and 0.1-400 microg/L (AMPA), acceptable reproducibility (RSD 5-7%, n=5), low limits of detection of 0.005 microg/L for GLYP and 0.06 microg/L for AMPA, and satisfactory relative recoveries (90-94%). Due to the low cost, the SLMTE device was disposed after each run which additionally eliminated the possibility of carry-over between runs. The validated method was tested for the analysis of both analytes in spiked tap water and river water with good success.
Glutamate receptors are the integral cellular components associated with excitotoxicity mechanism induced by the ischemic cascade events. Therefore the glutamate receptors have become the major molecular targets of neuroprotective agents in stroke researches. Recent studies have demonstrated that a Group I metabotropic glutamate receptor agonist, (S)-3,5-dihydroxyphenylglycine ((S)-3,5-DHPG) preconditioning elicits neuroprotection in the hippocampal slice cultures exposed to toxic level of N-methyl-d-aspartate (NMDA). We further investigated the preconditioning effects of (S)-3,5-DHPG on acute ischemic stroke rats. One 10 or 100μM of (S)-3,5-DHPG was administered intrathecally to Sprague-Dawley adult male rats, 2h prior to induction of acute ischemic stroke by middle cerebral artery occlusion (MCAO). After 24h, neurological deficits were evaluated by modified stroke severity scores and grid-walking test. All rats were sacrificed and infarct volumes were determined by 2,3,5-triphenyltetrazolium chloride staining. The serum level of neuron-specific enolase (NSE) of each rat was analyzed by enzyme-linked immunosorbent assay (ELISA). One and 10μM of (S)-3,5-DHPG preconditioning in the stroke rats showed significant improvements in motor impairment (P<0.01), reduction in the infarct volume (P<0.01) and reduction in the NSE serum level (P<0.01) compared to the control stroke rats. We conclude that 1 and 10μM (S)-3,5-DHPG preconditioning induced protective effects against acute ischemic insult in vivo.