Characterization of Empty Fruit Bunch Treated with Ionic Liquid Prior to Enzymatic Delignification

The technological utility of enzymes for delignification can be increased by using ionic liquid to open more accessible surface area for biomass transformation into bio-based products. The present paper demonstrates application of ionic liquid (IL) [emim][DEP] 1-ethyl-3 methyllimidazolium-diethyl phospate for empty fruit bunch (EFB) pretreatment process followed by enzymatic delignification by using Laccase.  It was found that [emim][DEP] increased the performance of the enzyme laccase and henced higher cellulose rich materials, whereas also reduced the lignin content in the EFB. The lowest lignin content obtained from IL-laccase treated EFB was approximately 17.92%, lower than the lignin content in the untreated EFB. Both treated and untreated EFB were characterized in chemical and physical properties by using scanning electron microscope (SEM), fourier transform infrared (FTIR), and thermogravimetric analysis (TGA/DTG) to observe the changes resulted from the pretreatment

AOT逆相ミセル反応場におけるC. V.リパーゼの活性化と安定化 : 酵素修飾とミセル修飾

取得学位：博士(学術)，学位授与番号：博甲第887号，学位授与年月日：平成19年3月22

Green Composites from Ionic Liquid-Assisted Processing of Sustainable Resources: A Brief Overview

The massive use of synthetic, petroleum-based polymeric composites has disturbed the fragile environmental equilibrium of our planet. Composites made solely from polysaccharides can offer unique intrinsic properties such as renewability, biodegradability, easy availability, eco-friendliness, facile processing, flexibility, and exciting physico-mechanical characteristics. The development of green processing of lignocellulosic materials and bio-based polymers such as cellulose, starch, chitin, and chitosan, the most abundant biorenewable materials on earth, is urgent from the perspectives of both environmental protection and sustainability in materials industries. Recently, the enormous potential of ionic liquids (ILs) as an alternative to ecologically harmful conventional organic solvents has been well recognized. Presently, a wide range of pronounced approaches have been explored to further improve the performance of ionic liquid-based processing of polysaccharides for green composite manufacturing. This review presents recent technological developments in which the advantages of ionic liquids as a dissolution medium for polysaccharides for production of plethora of green composites have been gradually realized

Micro-Credit as a Tool for Poverty Reduction in Bangladesh

Poverty has remained a global phenomenon and has defied various endeavors at curbing it especially in developing countries. The high and unacceptable number of people within its grip around the world gave it a pride of place as one of the major goals of Millennium Development Goals (MDGs) adopted in 2000. Poverty alleviation was a prime target of the MDGs and micro-credit was recognized as a veritable tool for tackling it. Since the 1970s, especially during the new wave of microfinance in the 1990s, micro-credit has come to be seen as an important development policy and a poverty reduction tool.  In this paper, we examined empirically the effect of micro-credit on poverty alleviation in Bangladesh using secondary data.  The results of the study show that poverty level is still high among the rural populace; but those that have access to micro-credit seems to have managed better than those who have no access to micro-credit. In other words, access to micro-credit has positive but not significant impact on poverty alleviation among the rural populace. The study recommends that government should intensify effort in its recent financial inclusion strategy to ensure that the rural populace has greater access to micro credits. Government should also ensure that interest rate on micro credits are affordable, the terms of the credits flexible and the conditions attached to the credit well liberalized. Keywords: Microcredit, Microfinance, Poverty, Eradication, Challenge

Ionic liquids as a potential solvent for lipase-catalysed reactions: a review

Ionic liquids (ILs) - as environmentally friendly “green” solvents- have been progressively used in various reactions as reagents, solvents and co-solvents including lipase-catalysed reactions. In fact, lipase-catalysed reactions in ILs are considered as a “green”-reaction and are more advantageous than chemical methods owing to the easy recovery of the product and the mild conditions of the reactions. The use of lipase in ILs provides many technological advantages compared to conventionally used solvents, such as selectivity enhancement, enzyme stability improvement, higher conversion rate, and better recyclability and recovery system. Nevertheless, in some cases, especially in hydrophilic ILs, lipase exhibits activity reduction when compared with organic solvents. Currently, various attempts have been made to enhance the performance of lipases in ILs. The main objective of this review is to demonstrate recent developments in the technology of using ILs as reaction media for lipase. It is expected that this review might be an inspiration in ILs assisted lipase-catalysed reactions to produce value-added materials including biofuels as well as biodiesel

Controllable phytosynthesis of gold nanoparticles and investigation of their size and morphology-dependent photocatalytic activity under visible light

© 2020 Elsevier B.V. Plants mediated synthesis of gold nanoparticles (AuNPs) containing desired characteristics for their suitable potential applications has been a challenging task, which is causing a major hindrance towards its commercialization. Therefore, herein phytosynthesis of AuNPs with required size and morphology has been achieved through manipulating the reaction conditions including reaction temperature and volume of Elaeis guineensis leaves (EGL) extract. Furthermore, photocatalytic potential of EGL mediated AuNPs having different size and shape has also been explored for the removal of methylene blue (MB) under visible light irradiation. The reaction temperature and volume of EGL strongly influenced the size and morphology of AuNPs, which are directly associated with the photocatalytic activities. The experimental results revealed that predominantly spherical and ultra-smaller size AuNPs with particle size of 16.26 ± 5.84 nm, formed at 70 °C showed the highest removal efficiency up to 92.55 % in 60 min. This highest photocatalytic activity of AuNPs could be attributed to the availability of higher number of low-coordinated gold (Au) atoms in the MB aqueous solution, which might have boosted the adsorption of the MB on the surface of particles and accelerated the degradation phenomenon. The proposed photocatalytic degradation mechanism of AuNPs for MB was also explained. The highly photoactive EGL mediated AuNPs with controllable morphology and size could be an advance step in future in chemical and biomedical applications

Effect of gold and iron nanoparticles on photocatalytic behaviour of titanium dioxide towards 1-butyl-3-methylimidazolium chloride ionic liquid

© 2019 Elsevier B.V. The high water solubility, chemical stability and low volatility of ionic liquids (ILs) have made them potentially persistent than conventional pollutants and toxic to the aquatic organisms. Therefore, extensive research efforts are being directed with an aim to develop cheap and efficient protocols to reduce the uncontrolled release of ILs in the environment. In the same line of action, titanium dioxide (TiO2) loaded with gold and iron nanoparticles were trialled for the photocatalytic degradation of highly concentrated 1-butyl-3-methylimidazolium chloride [BmimCl] ionic liquid. Furthermore, results pertaining to the degradation of the [BmimCl] using TiO2 loaded with gold nanoparticles (AuNPs) were compared with results obtained by using TiO2 loaded with Fe (NO3)3.9H2O and pristine TiO2 under same set of conditions. It was found that TiO2 decorated AuNPs demonstrated 7 times higher photocatalytic degradation for highly concentrated [BmimCl] in 60 min of reaction time in comparison to the pristine TiO2. Congruently, investigations also revealed that TiO2 loaded AuNPs expressed 3.3 times higher photocatalytic degradation of [BmimCl] in comparison to conventional photocatalyst TiO2@Fe under same reaction conditions. The higher photocatalytic performance associated with TiO2 loaded AuNPs was due to the enhanced Schottky barrier, which could have minimized the photocharge carrier resistance separation and migration. The mechanism for photocatalytic degradation of [BmimCl] using TiO2 loaded AuNPs has been also been described

Improved biological delignification of wood biomass via Ionic liquids pretreatment: A one step process

The enzymatic pretreatment of wood biomass for degrading lignin, a complex aromatic polymer, has received much attention as an environmentally safe or “green” process. However, this process for lignin degradation has been found to be very slow, even needed several months. To overcome this limitation, this study reports a new approach for enhanced enzymatic delignification of wood biomass using room temperature ionic liquids (RTILs)- a potentially attractive “green” and “designer” solvent- as (co)solvents or/and pretreated agents. The method comprised pretreatment of wood biomass prior to enzymatic delignification in ILs-aqueous systems with the aim of overcoming low delignification efficiency associated with the difficulties in enzyme accessibility to the solid substrate and the poor substrate and products solubility in aqueous system. The results showed that IL [emim] [OAc] (1-ethyl-3-methylimidazolium acetate) was better solvent for wood delignification than IL [bmim][Cl] (1-butyl-3-methylimidazolium chloride). The recovered cellulose rich materials obtained from combination effects of IL and biological pretreatment contained significantly lower amounts of lignin as compared to the amounts found when each method applied alone. The produced cellulose rich materials were characterized by acid hydrolysis, Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and X-ray diffractometry (XRD). SEM and XRD revealed considerable microstructural and crystallinity index changes in the pretreated cellulose rich materials.  We believe that this newly developed process will play a great role in converting cellulosic biomass- the most abundant renewable biomaterials in the world- to biomaterials, biopolymers, biofuels, bioplastics and hydrocarbons. Keywords: ionic liquids, wood biomass, cellulose, lignin, laccase, enzymatic delignification

Ecotoxicity Study of Amino Acid Ionic Liquids Towards Danio Rerio Fish: Effect of Cations

AbstractSix Ionic Liquids (ILs) were prepared based on phosphonium, ammonium and choline cations, with two types of amino acids specifically taurine and phenylalanine as anions. Good yields were obtained in the synthesis of the ILs. The toxicity of the synthesized ILs was checked against the Danio rerio fish (OECD 203). All six tested Amino Acid Ionic Liquids (AAILs) shows remarkably low toxicity towards Danio rerio fish

Facilitating enzymatic reactions by using ionic liquids: a mini review

Over the past two decades, ionic liquids (ILs) have been widely used for enzymatic conversions of substrates — especially substrates that are insoluble in common organic solvents and water — resulting in high conversion rates, high selectivity, and improved enzyme stability, wherein the ILs are recoverable and recyclable. Compared with performance in first-generation ILs, researchers recently considerably improved the technological utility of enzymes in second- and third-generation ILs composed of enzyme-benign cations and anions. Use of upgraded ILs with enzymes offers further improved activity and stability compared with research studies in the past decade, rendering IL-assisted biocatalytic processes more environmentally and economically attractive. This short review briefly presents recent developments of enzymatic reactions in ILs. The review covers approaches for and modifications of enzymes and ILs within the past 2 years for improved enzymes performance in ILs