Emerging Technologies for the Pretreatment of Lignocellulosic Biomass

Pretreatment of lignocellulosic biomass to overcome its intrinsic recalcitrant nature prior to the production of valuable chemicals has been studied for nearly 200 years. Research has targeted eco-friendly, economical and time-effective solutions, together with a simplified large-scale operational approach. Commonly used pretreatment methods, such as chemical, physico-chemical and biological techniques are still insufficient to meet optimal industrial production requirements in a sustainable way. Recently, advances in applied chemistry approaches conducted under extreme and non-classical conditions has led to possible commercial solutions in the marketplace (e.g. High hydrostatic pressure, High pressure homogenizer, Microwave, Ultrasound technologies). These new industrial technologies are promising candidates as sustainable green pretreatment solutions for lignocellulosic biomass utilization in a large scale biorefinery. This article reviews the application of selected emerging technologies such as ionizing and non-ionizing radiation, pulsed electrical field, ultrasound and high pressure as promising technologies in the valorization of lignocellulosic biomass

Lignocellulosic Biorefineries in Europe: Current State and Prospects

Lignocellulosic biorefining processes plant-derived biomass into a range of bio-based products. Currently, more than 40 lignocellulosic biorefineries are operating across Europe. Here, we address the challenges and future opportunities of this nascent industry by elucidating key elements of the biorefining sector, including feedstock sourcing, processing methods, and the bioproducts market

Rhetoric in the language of real estate marketing

“Des. Res.”, “rarely available”, “viewing essential” – these are all part of the peculiar parlance of housing advertisements which contain a heady mix of euphemism, hyperbole and superlative. Of interest is whether the selling agent’s penchant for rhetoric is spatially uniform or whether there are variations across the urban system. We are also interested in how the use of superlatives varies over the market cycle and over the selling season. For example, are estate agents more inclined to use hyperbole when the market is buoyant or when it is flat, and does it matter whether a house is marketed in the summer or winter? This paper attempts to answer these questions by applying textual analysis to a unique dataset of 49,926 records of real estate transactions in the Strathclyde conurbation over the period 1999 to 2006. The analysis opens up a new avenue of research into the use of real estate rhetoric and its interaction with agency behaviour and market dynamics

Moving Towards the Second Generation of Lignocellulosic Biorefineries in the EU: Drivers, Challenges, and Opportunities

The EU aims to achieve a variety of ambitious climate change mitigation and sustainable development goals by 2030. To deliver on this aim, the European Commission (EC) launched the bioeconomy strategy in 2012. At the heart of this policy is the concept of the sustainable Biorefinery, which is based centrally on a cost-effective conversion of lignocellulosic biomass into bioenergy and bioproducts. The first generation of biorefineries was based on utilization of edible food crops, which raised a “food vs. fuel” debate and questionable sustainability issues. To overcome this, lignocellulosic feedstock options currently being pursued range from non-food crops to agroforestry residues and wastes. Notwithstanding this, advanced biorefining is still an emerging sector, with unanswered questions relating to the choice of feedstocks, cost-effective lignocellulosic pretreatment, and identification of viable end products that will lead to sustainable development of this industry. Therefore, this review aims to provide a critical update on the possible future directions of this sector, with an emphasis on its role in the future European bioeconomy, against a background of global developments

Moving Towards the Second Generation of Lignocellulosic Biorefineries in the EU: Drivers, Challenges, and Opportunities

The EU aims to achieve a variety of ambitious climate change mitigation and sustainable development goals by 2030. To deliver on this aim, the European Commission (EC) launched the bioeconomy strategy in 2012. At the heart of this policy is the concept of the sustainable Biorefinery, which is based centrally on a cost-effective conversion of lignocellulosic biomass into bioenergy and bioproducts. The first generation of biorefineries was based on utilization of edible food crops, which raised a “food vs. fuel” debate and questionable sustainability issues. To overcome this, lignocellulosic feedstock options currently being pursued range from non-food crops to agroforestry residues and wastes. Notwithstanding this, advanced biorefining is still an emerging sector, with unanswered questions relating to the choice of feedstocks, cost-effective lignocellulosic pretreatment, and identification of viable end products that will lead to sustainable development of this industry. Therefore, this review aims to provide a critical update on the possible future directions of this sector, with an emphasis on its role in the future European bioeconomy, against a background of global developments

Biofabrication of magnetic nanoparticles and their use as carriers for pectinase and xylanase

In this study, superparamagnetic iron oxide nanoparticles (MNPs) were synthesized via exposure of fungal cell filtrate from Aspergillus flavus to aqueous iron ions. The extracellular synthesis of MNPs was monitored by UV–Vis spectrophotometry and showed an absorption peak at 310 nm. The morphology of MNPs was found to be flake-like, as confirmed by Field Emission Scanning Electron Microscopy (FESEM), while the average crystallite size was ∼16 nm, as determined by X-ray diffraction (XRD). Energy dispersive X-ray (EDX) analysis was performed to confirm the presence of elemental Fe in the sample. Pectinase and xylanase were covalently immobilized on MNPs with efficiencies of ∼84% and 77%, respectively. Compared to the free enzymes, the immobilized enzymes were found to exhibit enhanced tolerance to variation of pH and temperature and demonstrated improved storage stability. Furthermore, the residual activity of the immobilized enzymes was about 56% for pectinase and 52% for xylanase, after four and three consecutive use cycles, respectively

A Review on Bioconversion of Agro-Industrial Wastes to Industrially Important Enzymes

Agro-industrial waste is highly nutritious in nature and facilitates microbial growth. Most agricultural wastes are lignocellulosic in nature; a large fraction of it is composed of carbohydrates. Agricultural residues can thus be used for the production of various value-added products, such as industrially important enzymes. Agro-industrial wastes, such as sugar cane bagasse, corn cob and rice bran, have been widely investigated via different fermentation strategies for the production of enzymes. Solid-state fermentation holds much potential compared with submerged fermentation methods for the utilization of agro-based wastes for enzyme production. This is because the physical–chemical nature of many lignocellulosic substrates naturally lends itself to solid phase culture, and thereby represents a means to reap the acknowledged potential of this fermentation method. Recent studies have shown that pretreatment technologies can greatly enhance enzyme yields by several fold. This article gives an overview of how agricultural waste can be productively harnessed as a raw material for fermentation. Furthermore, a detailed analysis of studies conducted in the production of different commercially important enzymes using lignocellulosic food waste has been provided

Bioprocessing of brewers\u27 spent grain for production of xylanopectinolytic enzymes by Mucor sp.

The potential of microwave and ultrasound was evaluated for the pretreatment of brewer\u27s spent grain (BSG). Under optimal conditions of microwave and ultrasound pretreatments, reducing sugar yields per 1 g of pretreated BSG were 64.4 ± 7 mg and 39.9 ± 6 mg, respectively. Subsequently, the pretreated BSG was evaluated as a substrate for production of Xylanopectinolytic enzymes using fungi isolated from spoiled fruits. Out of twenty-nine (29) isolates recovered, Mucor sp. (AB1) isolated from Bramley apple (Malus domestica) produced xylanopectinolytic enzymes with higher specific activity, and was selected for further studies. The highest enzyme activity (137 U/g, and 67 U/g BSG, for pectinase and xylanase, respectively) was achieved in a medium that contained 15 g of BSG, at pH 6, temperature of 30 °C, supplemented with 1% xylan or pectin for inducing the production of xylanase or pectinase, respectively. The partially purified xylanopectinolytic enzymes were optimally active at 60 °C and pH 5