Pectinases, member of the hydrolases family of enzymes, are one of the important enzymes of the biotechnological sector with 25% share in the global food and beverage enzyme market. They hold a ...leading position among the commercially produced industrial enzymes. These enzymes are sustainable and environmentally-friendly tool of nature with wide application perspective in many industrial processes, such as, retting and degumming of plant fibers, fermentation of tea and coffee, oil extraction, clarification of fruit juices and wine, valorization of industrial wastes, debasement of cellulosic biomass for biofuel production, wastewater remediation, desizing, scouring and bleaching of fabric, animal feed production, and protoplast fusion technology etc. However, like many other industrial enzymes, pectinases also face the constraint of low yield and productivity in its economized production. Therefore, pectinases have been the target of studies aiming to achieve the expression levels on a commercial scale. Among the natural sources of pectinases, microbial pectinases are employed frequently owing to its ease of production and unique physicochemical properties. This review mainly focuses on the production of pectinase enzymes along with different types of recent strategies used for their production optimization to get overexpression/production. The promise of genetic engineering approaches applied so far to get the higher production of these enzymes using simpler molecular devices and simple fermentation media is also covered in this review.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In view of promising adsorption efficiency of biocomposites, the removal of imidacloprid was studied using biocomposites of polypyrole (PPY), polyaniline (PAN) and sodium alginate (Na-Alginate) with ...peanut husk (PH). The affecting variables such as pH, insecticide concentration, composite dose, contact time, temperature were optimized for efficient removal of imidacloprid. The biocomposites showed promising efficiency for the removal of imidacloprid. Among all composites polypyrole composite exhibited maximum efficiency at pH 3, 0.05 g adsorbent dose, 90 min contact time, 25 mg/L initial concentration at 35 °C. Langmuir, Freundlich, Harkins-Jura and Temkin isotherms models were applied on the experimental data. The best fitted were Langmuir and Freundlich isotherms with R2 value > 0.904 and >0.97, respectively. Insecticide adsorption followed the pseudo first order kinetics model. Thermodynamics (free energy, enthalpy and entropy) study revealed that the insecticide adsorption process on to biocomposites was spontaneous and exothermic in nature. This study revealed that the polypyrole, polyaniline and sodium alginate composites with peanut husk have promising adsorption potential and this class of adsorbent could be used for the remediation of wastewater contains imidacloprid insecticide.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Lipase-mediated polymer degradation is a robust alternative approach to conventional methods due to biocompatibility and mild conditions. In the present study, response surface methodology was ...applied to improve the production of lipase from
Penicillium fellutanum
by optimization of various process parameters. Under the optimized bioprocess conditions of pH 5.0, incubation time 24 h, temperature 35 °C, and lactose as an additional carbon source in 40 experimental runs, the maximum lipase titer of 1038.86 U/gds was achieved, 2.05-fold higher than the lipase yield in basal medium. All the linear and interactive coefficients (except linear carbon source) were found significant by analysis of variance. The as-synthesized cell-free lipase extract was partially purified by ammonium sulfate fractionation and dialysis (2.06-folds, 272.37 U/mg proteins) and applied to the degradation of polyester vylon 200. The biocatalytic action of the enzyme results in an 81% weight loss of PV-200 after 7 days of incubation at pH 7.5 and 35 °C. Different characterization techniques, i.e., SEM, FT-IR, and DSC corroborated the lipase-catalyzed degradation of PV-200. The untreated polyester film had a smooth surface, while after enzymatic treatment, deformities and various micron-sized holes and cracks appeared on the film surface. In conclusion, the outcomes of study display a high potential of lipase as green and ecofriendly biocatalyst for efficient degradation and depolymerization of polyester for environmental safety.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Recent progress in the recycling and recovery of polyurethane and polyurethane composites is reviewed. The various types of polyurethane waste products, consisting of either old recycled parts or ...production waste, are generally reduced to a more usable form, such as flakes, powder or pellets, depending on the particular type of polyurethane that is being recycled. The various recycling technologies for material and chemical recycling of PU materials have greatly contributed to improve the overall image regarding the recyclability of polyurethanes in recent years, by far the most important being regrinding and glycolysis. These technologies open an emerging, effective and economic route for recycling polyurethane rigid foams and composite. Polyurethane foam in automotive seating has been successfully recycled using regrind technology. Glycolysis of polyurethanes can be economically acceptable, but still requires more development in order to tolerate more contamination in the post-consumer material. Current technologies can recover the inherent energy value of polyurethanes and reduce fossil fuel consumption. Energy recovery is considered the only suitable disposal method for recovered material for which no markets exist or can be created. Increasing waste-to-energy and other thermal processing activities involving gasification, pyrolysis and two-stage combustion has contributed for the disposal of significant amounts of scrap PU without many difficulties. It is concluded that many of the plastic feedstock recycling processes appear to be technically feasible and robust enough to warrant further development in the future.
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► Microbial transformation is an important tool for structural modification of compounds. ► Steroidal compounds are responsible for important biological functions in the cells. ► Structural ...modifications of bioactive steroids by microorganisms have been reported. ► The review covers the literature from 1994 to 2011.
Microbial transformation is an important tool for structural modification of organic compounds, especially natural products with complex structures like steroids. It can be used to synthesize chemical structures that are difficult to obtain by ordinary methods and as a model of mammalian metabolism due to similarity between mammalian and microbial enzyme systems. During recent years research has been focused on the structural modifications of bioactive steroids by using various microorganisms, in order to obtain biologically potent compounds with diverse structures. Steroidal compounds are responsible for important biological functions in the cells and manifest a variety of activities. This article covers the microbial transformation of sterols, steroidal hormones and some new types of steroids known as bufadienolides. Emphasis has placed on reporting metabolites that may be of general interest and on the practical aspects of work in the field of microbial transformations. The review covers the literature from 1994 to 2011.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The present study deals with the utilization of an inexpensive agro-industrial waste rice husk for the removal of Direct Red-31 and Direct Orange-26 from aqueous solutions in a batch mode. ...Experiments were carried out as function of pH, biosorbent dose, particle size of biosorbent, initial dyes concentration, contact time and temperature. The equilibrium biosorption data were analyzed by Langmuir, Freundlich, Temkin, Doubinin–Radushevich (D–R) and Harkins–Jura isotherm models. The results indicated that the Langmuir model provided the best correlation of the experimental data for both dyes. The biosorption kinetic data were modeled using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetic equations. It was observed that the pseudo-second-order kinetic equation could explain the biosorption kinetics of dyes on rice husk. Thermodynamic parameters such as enthalpy change (ΔH°), entropy change (ΔS°) and free energy change (ΔG°) were also investigated. Free energy change showed that biosorption of Direct Red-31 and Direct Orange-26 was spontaneous at all studied temperatures (30–70
°C). Surface adsorption of both the dyes at specific binding sites was confirmed through and Fourier Transform infrared spectroscopic (FT-IR) analysis. The changes in surface morphology of rice husk before and after adsorption was investigated through scanning electron microscopy (SEM). It was implied that rice husk may be suitable as an adsorbent for removal of direct dyes from aqueous solutions.
► We used low cost rice husk for the removal of direct dyes from aqueous solution. ► pH of the medium strongly affected the removal of direct dyes. ► Langmuir model provided the best correlation of the experimental data dyes. ► Thermodynamics showed that removal of dyes was spontaneous at studied temperature. ► Results indicated that optimum removal of dyes depends on process parameters.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Slag produced as a byproduct in industrial processes, contains considerable metals contents, which need to be recovered to avoid environmental contamination. In present review, the types, ...applications, recovery of metals from slag and their hazardous effects have been discussed. Gravimetric, magnetic, floatation, pyrometallurgical and hydrometallurgical treatments are discussed for processing of charge chrome, steel, copper smelter, brass smelter, tin, incineration, ferrochrome and silico-manganese slags for the extraction of various metal ions (Mg, Cu, Zn, Pb, Cd, Ni, Co, Mn, Fe, As, Cr, Al, Nb, Ag, Au, Nb, Ta, Cu, Co, Ni, Fe, V, Cr). The possibility of biometallurgical processing of slags is also evaluated. Merits and demerits of extraction and purification techniques are highlighted with possible suggestions and possibility of integrated leaching techniques is also discussed.
Textile industries use dyes to color their products and release waste water containing dyes, causing water pollution which is a serious problem for survival of human life on earth. The decolorization ...of basic turquise blue X-GB (BTB X-GB) 250% and basic blue X-GRRL (BB X GRRL) 250% dyes was examined by advanced (Fenton process) oxidation process. The effects of different parameters (initial dye concentration, pH, concentrations of hydrogen peroxide (H
) and reaction time) have been examined and optimum conditions were determined. It has been noted that percentage decolorization of both dyes (50 mg/L) increases with increase in concentration of H
. At optimum conditions (pH=3.0, H
=4.8 mM, temperature=50°C, time=80 min of BTB X-GB, and pH=5.0, H
=5.6 mM, temperature=40°C, time=60 min of BB X-GRRL) the decolorization obtained by Fenton process was 85.83% of BTB X-GB and 74.98% for BB X-GRRL. 1
order, 2
order and BMG kinetic models were used to analyze the data. BMG model gives us the higher values of correlation coefficients for all data. Results showed that Fe
/H
are most effective for oxidation treatment of waste water effluents containing dyes as main pollutants.
Batch and column adsorption modes were compared for the adsorption of U(VI) ions using rice husk waste biomass (RHWB). Response surface methodology was employed for the optimization of process ...variables, i.e., (pH (A), adsorbent dose (B), initial ion concentration (C)) in batch mode. The B, C and C
affected the U(VI) adsorption significantly in batch mode. The developed quadratic model was found to be validated on the basis of regression coefficient as well as analysis of variance. The predicted and actual values were found to be correlated well, with negligible residual value, and B, C and C
were significant terms. The column study was performed considering bed height, flow rate and initial metal ion concentration, and adsorption efficiency was evaluated through breakthrough curves and bed depth service time and Thomas models. Adsorption was found to be dependent on bed height and initial U(VI) ion concentration, and flow rate decreased the adsorption capacity. Thomas models fitted well to the U(VI) adsorption onto RHWB. Results revealed that RHWB has potential to remove U(VI) ions and batch adsorption was found to be efficient versus column mode.
Anticancer-drug delivery is now becoming a challenging approach for researchers as it allows controlled drug delivery near cancerous cells with minimized generic collection and the avoidance of ...secondary side effects. Hence in this work, the applications of nanostructures as anticancer drug-delivery carriers were widely investigated to target cancerous tissues. Based on DFT calculations, we investigated the transition metal-doped boron nitride nanostructure as a drug-delivery agent for the gemcitabine drug utilizing the B3LYP/6-31G (d, p) level of theory. In this research, the adsorption energy and electronic parameters of gemcitabine on the interaction with the metal-doped BN nanostructures were studied. It has been observed that metal doping significantly enhances the drug-delivery properties of BN nanostructures. Among the investigated nanostructures, Ni-BN has been found to be the most prominent nanostructure to transport gemcitabine with an elevated value of adsorption energy in both the gas phase (−45.79) and water media (−32.46). The interaction between gemcitabine and BN nanostructures was confirmed through frontier molecular orbitals and stabilization energy analysis. The fractional charge transfer, MEP, NCI, and NBO analyses exposed the charge transfer from drug molecule to the BN nanostructures. Transition density maps and UV-VIS spectra were also plotted to investigate the excited-state properties of the designed complexes. Thus, the present study provides an in-depth interaction mechanism of the gemcitabine drug with BN, which reveals that metal-doped BN nanostructures can be a favorable drug-delivery vehicle for the gemcitabine anticancer drug.
Anticancer-drug delivery is now becoming a challenging approach for researchers as it allows controlled drug delivery near cancerous cells with minimized generic collection and the avoidance of secondary side effects.
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