The use of routine monitoring of donor-derived cell-free DNA (dd-cfDNA) after kidney transplant may allow clinicians to identify subclinical allograft injury and intervene prior to development of clinically evident graft injury. To evaluate this, data from 1092 kidney transplant recipients monitored for dd-cfDNA over a three-year period was analyzed to assess the association of dd-cfDNA with histologic evidence of allograft rejection. Elevation of dd-cfDNA (0.
View Article and Find Full Text PDFBackground: Producing valuable fuels and chemicals from lignin is a key factor for making lignocellulosic biomass economically feasible; however, significant roadblocks exist due to our lack of detailed understanding of how lignin is enzymatically depolymerized and of the range of possible lignin fragments that can be produced. Development of suitable enzymatic assays for characterization of putative lignin active enzymes is an important step towards improving our understanding of the catalytic activities of relevant enzymes. Previously, we have successfully built an assay platform based on glycan substrates containing a charged perfluorinated tag and nanostructure-initiator mass spectrometry to study carbohydrate active enzymes, especially various glycosyl hydrolyses.
View Article and Find Full Text PDFDepolymerization of procyanidin polymers into oligomers enhances their bioavailability and bioactivity because oligomers are bioavailable. Hydrogenolysis was applied in this study to depolymerize hi-tannin sorghum bran procyanidin polymers into oligomers. The yield and composition of oligomers under different hydrogenolysis conditions was investigated.
View Article and Find Full Text PDFBy mimicking natural lignin degradation systems, the Fenton catalyst (Fe(3+), H2O2) can effectively facilitate lignin depolymerization in supercritical ethanol (7 MPa, 250 °C) to give organic oils that consist of mono- and oligomeric aromatics, phenols, dicarboxylic acids, and their derivatives in yields up to (66.0±8.5) %.
View Article and Find Full Text PDFBiotechnol Biofuels
December 2014
Background: A key focus in sustainable biofuel research is to develop cost-effective and energy-saving approaches to increase saccharification of lignocellulosic biomass. Numerous efforts have been made to identify critical issues in cellulose hydrolysis. Aerobic fungal species are an integral part of the carbon cycle, equip the hydrolytic enzyme consortium, and provide a gateway for understanding the systematic degradation of lignin, hemicelluloses, and cellulose.
View Article and Find Full Text PDFOleaginous fungi capable of accumulating a considerable amount of lipids are promising sources for lipid-based biofuel production. The specific productivities of filamentous fungi in submerged fermentation are often correlated with morphological forms. However, the relationship between morphological development and lipid accumulation is not known.
View Article and Find Full Text PDFThe structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation chromatography (GPC), quantitative (13)C, and 2-D nuclear magnetic resonance (NMR). The structural analysis revealed that ethanol extractable lignin preserved basic lignin structure, but had relatively lower amount of β-O-4 linkages, syringyl/guaiacyl units ratio (S/G), p-coumarate/ferulate ratio, and other ending structures.
View Article and Find Full Text PDFJ Agric Food Chem
November 2013
A further understanding of the structure of lignin from herbaceous crops is needed for advancing technologies of lignocellulosic biomass processing and utilization. A method was established in this study for analyzing structural motifs found in milled straw lignin (MSL) and cellulase-digested lignin (CEL) isolated from wheat straw by combining quantitative (13)C and HSQC NMR spectral analyses. The results showed that guaiacyl (G) was the predominant unit in wheat straw cell wall lignin over syringyl (S) and hydroxyphenyl (H) units.
View Article and Find Full Text PDFCulture conditions including nitrogen source and concentration, xylose concentration, and inoculum level were evaluated for the effect on cell growth and lipid production of an oleaginous fungus, Mortierella isabellina, grown on xylose. Yeast extract and ammonium sulfate were found to be the best amongst the organic and inorganic nitrogen sources tested, respectively. Subsequent combination of these two nitrogen sources at a nitrogen ratio of 1:1 further enhanced lipid production.
View Article and Find Full Text PDFVarious carbon sources including monosugars, disaccharides and carboxymethyl-cellulose (CMC) were used for single-cell oil production by the filamentous fungus Mortierella isabellina. In addition, the inhibitory effects of lignocellulose-derived compounds (lignin aldehydes, furan aldehydes and weak acid) were investigated. C6 sugars were preferably used for growth compared to C5 sugars.
View Article and Find Full Text PDFBackground: Lipids produced from filamentous fungi show great promise for biofuel production, but a major limiting factor is the high production cost attributed to feedstock. Lignocellulosic biomass is a suitable feedstock for biofuel production due to its abundance and low value. However, very limited study has been performed on lipid production by culturing oleaginous fungi with lignocellulosic materials.
View Article and Find Full Text PDFInorganic salts and tween 80 are known to induce the lignin degrading peroxidase expression of Phanerochaete chrysosporium in submerged culture. In this study, the wheat straw pretreatment supplemented with inorganic salts (salts group), tween 80 (plus) and no supplementation to the biomass (minus) were examined. Among the solid state fermentation groups, salts group resulted in a substantial degradation of wheat straw within one week, along with the highest lignin loss (25%) and ∼250% higher efficiency for the total sugar release through enzymatic hydrolysis.
View Article and Find Full Text PDF