Hemicellulose, a structural polysaccharide and often underutilized co-product stream of biorefineries, could be used to produce prebiotic ingredients with novel functionalities. Since hot water pre-extraction is a cost-effective strategy for integrated biorefineries to partially fractionate hemicellulose and improve feedstock quality and performance for downstream operations, the approach was applied to process switchgrass (SG), hybrid poplar (HP), and southern pine (SP) biomass at 160°C for 60 min. As a result, different hemicellulose-rich fractions were generated and the chemical characterization studies showed that they were composed of 76-91% of glucan, xylan, galactan, arabinan, and mannan oligosaccharides.
View Article and Find Full Text PDFBackground: Lignocellulosic biomass requires either pretreatment and/or fractionation to recover its individual components for further use as intermediate building blocks for producing fuels, chemicals, and products. Numerous ionic liquids (ILs) have been investigated for biomass pretreatment or fractionation due to their ability to activate lignocellulosic biomass, thereby reducing biomass recalcitrance with minimal impact on its structural components. In this work, we studied and compared 1-allyl-3-methylimidazolium formate ([AMIM][HCOO]) to the commonly used 1-ethyl-3-methylimidazolium acetate ([EMIM][CHCOO]) for its potential to activate hybrid poplar biomass and enable high cellulose and hemicellulose enzymatic conversion.
View Article and Find Full Text PDFLoblolly pine residues have enormous potential to be the raw material for advanced biofuel production due to extensive sources and high cellulose content. Hot water (HW) pretreatment, while being a relatively economical and clean technology for the deconstruction of lignocellulosic biomass, could also inhibit the ensuing enzymatic hydrolysis process because of the production of inhibitors. In this study, we investigated the effect of oligosaccharide fractions purified from HW pre-hydrolyzate of pinewood using centrifugal partition chromatography (CPC) on three recombinant cellulolytic enzymes (E1, CBHI and CBHII), which were expressed in the transgenic corn grain system.
View Article and Find Full Text PDFSynthesizing lignin-based copolymers would valorize a major coproduct stream from pulp and paper mills and biorefineries as well as reduce the dependence on petrochemical-based consumer goods. In this study, we used organosolv lignin isolated from hybrid poplar ( Populus trichocarpa × P. deltoides) to generate lignin-containing methacrylate hydrogels.
View Article and Find Full Text PDFBackground: The recent intense attention to hospital readmissions and their implications for quality, safety, and reimbursement necessitates understanding specific subsets of readmitted patients. Frequently admitted patients, defined as patients who are admitted 5 or more times within 1 year, may have some distinguishing characteristics that require novel solutions.
Methods: A comprehensive administrative database (University HealthSystem Consortium's Clinical Data Base/Resource Manager) was analyzed to identify demographic, social, and clinical characteristics of frequently admitted patients in 101 US academic medical centers.
Laccases have wide range of substrate specificity and find applications from pulp industry to waste water remediation. Laccases have also been used in combined pretreatment of biomass hydrolyzates to remove enzymatic and fermentation inhibitors. In this study, laccase production by Trametes versicolor strains isolated from different regions of the United States was induced using copper salts.
View Article and Find Full Text PDFPretreatment and enzymatic saccharification are two major upstream processes that affect the economic feasibility and sustainability of lignocellulosic biofuel production. Cellulase-inhibiting degradation products, generated during dilute acid pretreatment, increase enzyme usage, and therefore, it is essential to mitigate their production. In an attempt to elucidate the most deleterious degradation product to enzymatic hydrolysis, hydrolyzates were generated from rice straw, and their effect on enzyme activity was determined.
View Article and Find Full Text PDFXylose oligomers are the intermediate products of xylan depolymerization into xylose monomers. An understanding of xylan depolymerization kinetics is important to improve the conversion of xylan into monomeric xylose and to minimize the formation of inhibitory products, thereby reducing ethanol production costs. The study of xylan depolymerization requires copious amount of xylose oligomers, which are expensive if acquired commercially.
View Article and Find Full Text PDFXylose oligomers, which have a prebiotic effect, have been used as additives to human and animal food. These oligomers are also the primary intermediate in hemicellulose degradation during the pretreatment of biomass. Centrifugal partition chromatography (CPC) was used in this study to separate and purify xylan-derived oligomers from birchwood xylan.
View Article and Find Full Text PDFPopulus sp. are hardwood feedstocks that grow in forest management areas that are logged for softwoods; however, they are also being considered as an energy-destined feedstock. The objective of this work was to determine the effect of xylose yield from dilute acid and hot water pretreatments performed in unstirred batch stainless steel reactors at temperatures ranging from 140 to 200°C.
View Article and Find Full Text PDFBiotechnol Prog
January 2011
Antioxidant stilbenoids, such as resveratrol, arachidin-1, and arachidin-3, have demonstrated beneficial effects on human health. Although resveratrol is commercially available, arachidin-1 and arachidin-3 are not, resulting in an opportunity to explore purification methods and to confirm biological activity. Recently, Arachis hypogaea hairy root cultures (produced via Agrobacterium rhizogenes-mediated transformation) were reported to secrete stilbenoids into liquid growth media upon elicitation in quantities sufficient for commercial production.
View Article and Find Full Text PDFLiquidambar styraciflua L., also known as sweetgum, is an understory hardwood species that has widespread distribution in the southeast USA, especially in pine plantations. In addition to being a possible biorefinery feedstock, sweetgum contains shikimic acid, which is a precursor for the drug Tamiflu.
View Article and Find Full Text PDFSwitchgrass (Panicum virgatum L.) has recently received significant attention as a possible feedstock for the production of liquid fuels such as ethanol. In addition, switchgrass may also be a source of valuable co-products, such as antioxidants, and our laboratory recently reported that switchgrass contains policosanols and alpha-tocopherol.
View Article and Find Full Text PDFUsing switchgrass ( Panicum virgatum L.) as a cellulosic feedstock for the production of ethanol could lead to the extraction of co-products prior to the pretreatment step, thereby adding value to the ethanol conversion process. Policosanols, registered as 142583-61-7, are present in Poaceae and are a mixture of long-chained primary alcohols.
View Article and Find Full Text PDFSilymarin encompasses a group of flavonolignans that are extracted from Silybum marianum (Asteraceae) fruits. The silymarins have previously been reported to lower low-density lipoprotein (LDL) levels associated with high-fat diets. The present study reports the efficacy of the silymarins in inhibiting oxidized low-density lipoprotein (oxLDL) generation and subsequent scavenger receptor (SR) mediated monocyte adherence to oxLDL.
View Article and Find Full Text PDFCytochrome P450 2D6 (CYP2D6), an important CYP isoform with regard to drug-drug interactions, accounts for the metabolism of approximately 30% of all medications. To date, few studies have assessed the effects of botanical supplementation on human CYP2D6 activity in vivo. Six botanical extracts were evaluated in three separate studies (two extracts per study), each incorporating 16 healthy volunteers (eight females).
View Article and Find Full Text PDFSilybum marianum contains flavonolignans, termed silymarin (SM), that are therapeutic agents for many inflammation-based diseases including atherosclerosis. Oxidation of human low-density lipoprotein was induced by CuSO4 or J774 macrophage cells and measured by the formation of thiobarbituric acid reactive substances (TBARS). SM was extracted by pressurized hot water (PHWE) or ethanol, and the effects of these extracts on TBARS formation were evaluated in comparison with those of SM preparations made from blending masses of individual flavonolignan standards in ratios identical to those of the water and ethanol extracts.
View Article and Find Full Text PDFMilk thistle (Silybum marianum L.) seed meal is extracted for the flavonolignans, silychristin, silydianin, silybinin A, silybinin B, isosilybinin A and isosilybinin B, which are collectively known as the silymarin complex. To obtain the flavonolignans, the meal is usually treated with successive washes of petroleum ether to remove the lipids, followed by extraction of the flavonolignans with ethanol.
View Article and Find Full Text PDFHigh-value phytochemicals could be extracted from biomass prior to the current cellulosic pretreatment technologies (i.e., lime, ammonia, dilute acid, or pressurized hot water treatments) provided that the extraction is performed with a solvent that is compatible with the pretreatment.
View Article and Find Full Text PDFAppl Biochem Biotechnol
September 2006
Mimosa, an excellent energy crop candidate because of its high growth yield, also contains, on a dry basis, 0.83% hyperoside and 0.90% quercitrin.
View Article and Find Full Text PDFOxygen radical absorbance capacity (ORAC) values showed that methanolic extracts of Albizia julibrissin foliage displayed antioxidant activity. High performance liquid chromatography (HPLC) and mass spectrometry (MS) techniques were utilized in the identification of the compounds. The analysis confirmed the presence of three compounds in A.
View Article and Find Full Text PDFPhytochemical-mediated modulation of cytochrome P450 enzymes (CYPs) may underlie many herb-drug interactions. This study's purpose was to assess the effects of milk thistle and black cohosh supplementation on CYP3A activity and compare them to a clinically recognized inducer, rifampin, and inhibitor, clarithromycin. Healthy volunteers were randomly assigned to receive a standardized milk thistle (900 mg) or black cohosh (80 mg) supplement for 14 days.
View Article and Find Full Text PDFSperm gain full ability to bind to the zona(e) pellucida(e) (ZP) during capacitation. Since lipid rafts are implicated in cell adhesion, we determined whether capacitated sperm lipid rafts had affinity for the ZP. We demonstrated that lipid rafts, isolated as low-density detergent resistant membranes (DRMs), from capacitated pig sperm had ability to bind to homologous ZP.
View Article and Find Full Text PDFKudzu (Pueraria lobata) foliage has been touted as a possible energy crop. High-performance liquid chromatography and mass spectrometry analysis of the methanolic kudzu foliage extracts confirmed the presence of robinin (kaempferol-3-O-robinoside-7-O-rhamnoside). Robinin accounted for 0.
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