Biological activity of leaves and stems extracts of Artemisia herba-alba from the Oriental region of Morocco and extraction of Cellulose from this plant (isolation, modification and applications)

 Biopolymers are polymers that originate from biological sources. Due to their renewable biodegradability and abundance, they present themselves as a high potential source of innovation for several industrial applications. Polysaccharides, and in particular cellulose, today arouse great interest due to its high abundance, wide distribution, and low cost. It is considered one of the most popular organic polymers and an almost eternal source of raw materials for the growing demand for environmentally eco-friendly materials. First, we evaluated the biological activity (Antioxidant and Antimicrobial) of aqueous and organic extracts of Artemisia herba-alba. Second, we extracted and isolated cellulose from the stems and leaves of this plant. Third, the cellulose was modified to improve its solubility and activity using an acrylamide compound. Finally, we investigated the ability of cellulose acrylate to trap copper(II) ions in water. The objective of the study is to promote and maintain an eco-friendly environment with emphasis on water as a vital source

Comparative study of inhibitory efficacy of methionine and its derivatives in acidic medium by mild steel

Corrosion inhibition effect of L-Methionine (MT1), L-Methionine sulfoxide (MT2) and L-Methionine sulfone (MT3) on mild steel corrosion in 1M HCl solution was studied by using weight loss, electrochemical polarization and electrochemical impedance spectroscopy (EIS) techniques. The experimental results showed that the inhibitory efficiency of the three aminoacids improves with the increase of concentration to reach the maximum value of 95.20% for MT1, 94.14% for MT2 and 88.92% for MT3 for a concentration of 10-3M, which translates that the surface covered by the inhibitor increases with the concentration. The effect of temperature on the corrosion rate was investigated and some thermodynamic parameters were calculated. Polarization studies show that three studied inhibitors suggested that three inhibitors control the anodic as well as cathodic reactions and act as mixed type in nature. The results show that MT1, MT2 and MT3 are good inhibitors, and the adsorption of each inhibitor on mild steel surface obeys Flory-Huggins and Langmuir, with a better fit of the Langmuir isotherm through mixed adsorption (physisorption as well as chemisorption) process. In addition, the quantum approach based on density functional theory (DFT), monte Carlo (MC) and molecular dynamics (MD) simulations was confirmed the reactivity of the studied compound towards the corrosion process

Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

<p>Abstract</p> <p>Background</p> <p>The model bacterium <it>Clostridium cellulolyticum </it>efficiently degrades crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H₂and CO₂, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels production. Therefore genetic engineering will likely be required to improve the ethanol yield. Plasmid transformation, random mutagenesis and heterologous expression systems have previously been developed for <it>C. cellulolyticum</it>, but targeted mutagenesis has not been reported for this organism, hindering genetic engineering.</p> <p>Results</p> <p>The first targeted gene inactivation system was developed for <it>C. cellulolyticum</it>, based on a mobile group II intron originating from the <it>Lactococcus lactis </it>L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous <smcaps>L</smcaps>-lactate dehydrogenase (<it>Ccel_2485; ldh</it>) and <smcaps>L</smcaps>-malate dehydrogenase (<it>Ccel_0137; mdh</it>) genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain, resulting in a substantial shift in fermentation toward ethanol production. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products, corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant's tricarboxylic acid pathway.</p> <p>Conclusions</p> <p>The efficient intron-based gene inactivation system produced the first non-random, targeted mutations in <it>C. cellulolyticum</it>. As a key component of the genetic toolbox for this bacterium, markerless targeted mutagenesis enables functional genomic research in <it>C</it>. <it>cellulolyticum </it>and rapid genetic engineering to significantly alter the mixture of fermentation products. The initial application of this system successfully engineered a strain with high ethanol productivity from cellobiose, cellulose and switchgrass.</p

Aspects of follicular and oocyte maturation that affect the developmental potential of embryos

International audienc

Ovarian stimulation following repeated injections of LH or LH+FSH in Ile-de-France sheep in early and mid-seasonal anoestrus

International audienc

Ovarian stimulation following repeated injections of LH or LH+FSH in Ile-de-France sheep in early and mid-seasonal anoestrus

International audienc