1,721,020 research outputs found
Review of US and EU initiatives toward development, demonstration, and commercialization of lignocellulosic biofuels
No full textConversion of biomass into renewable energy and renewable fuels/product
Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and Liquid Chromatography-Multiplexed Collision Induced Dissociation-Mass Spectrometry
No full textThermochemical pretreatment of cellulosic biomass improves cell wall enzymatic digestibility, while simultaneously releasing substantial amounts of soluble oligosaccharides. Profiling of oligosaccharides released during pretreatment yield information essential for choosing glycosyl hydrolases necessary for cost-effective conversion of cellulosic biomass to desired biofuel/biochemical end-products. In this report we present a methodology for profiling of soluble neutral oligosaccharides released from ammonia fiber expansion (AFEXTM)-pretreated corn stover. Our methodology employs solid phase extraction (SPE) enrichment of oligosaccharides based on porous graphitized carbon (PGC), followed by high performance liquid chromatography (HPLC) separation using a polymeric amine based column (Prevail Carbohydrate ES) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) in both positive and negative modes. For structural elucidation on the chromatographic time scale, nonselective multiplexed collision-induced dissociation was performed for quasi-simultaneous acquisition of accurate molecular and fragment masses of neutral oligosaccharids in a single analysis. These analyses directly revealed presence of glucans up to degree of polymerization (DP) 22 without side-chain modifications. Additionally, arabinoxylans with DP up to 6 were detected in the pretreated biomass samples (post-enzymatic digestion). All linkages between sugar units in glucans and arabinoxylans were identified to be p-1-4 linkages based on cross-ring fragment masses. Comprehensive profiling of soluble oligosaccharides also demonstrated that arabinoxylan acetylation was reduced by greater than 85% post-AFEXTM treatment.Published version: Vismeh, Ramin, Humpula, James F., Chundawat, Shishir P. S., Balan, Venkatesh, Dale, Bruce E. & Jones, A. Daniel. (2013). Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and LC-TOF MS. Carbohydrate Polymers 94(2), 791-799. http://dx.doi.org/10.1016/j.carbpol.2013.02.00
Probing the nature of AFEX-pretreated corn stover derived decomposition products that inhibit cellulase activity
No full textSequential fractionation of AFEX-pretreated corn stover extracts was carried out using ultra-centrifugation, ultra-filtration, and solid phase extraction to isolate various classes of pretreatment products to evaluate their inhibitory effect on cellulases. Ultra-centrifugation removed dark brown precipitates that caused no appreciable enzyme inhibition. Ultra-filtration of ultra-centrifuged AFEX-pretreated corn stover extractives using a 10 kDa molecular weight cutoff (MWCO) membrane removed additional high molecular weight components that accounted for 24–28% of the total observed enzyme inhibition while a 3 kDa MWCO membrane removed 60–65%, suggesting significant inhibition is caused by oligomeric materials. Solid phase extraction (SPE) of AFEX-pretreated corn stover extractives after ultra-centrifugation removed 34–43% of the inhibition; ultra-filtration with a 5 kDa membrane removed 44–56% of the inhibition and when this ultra-filtrate was subjected to SPE a total of 69–70% of the inhibition were removed. Mass spectrometry found several phenolic compounds among the hydrophobic inhibition removed by SPE adsorption.Published version: Humpula, James F., Uppugundla, Nirmal, Vismeh, Ramin, Sousa, Leonardo, Chundawat, Shishir P. S., Jones, A. Daniel, Balan, Venkatesh, Dale, Bruce E. & Cheh, Albert M. (2014). Probing the nature of AFEX-retreated corn stover derived decomposition products that inhibit cellulase activity. Bioresource Technology 152, 38-45. http://dx.doi.org/10.1016/j.biortech.2013.10.08
Saccharification of newspaper waste after ammonia fiber expansion or extractive ammonia
Full text linkThe lignocellulosic fractions of municipal solid waste (MSW) can be used as renewable resources due to the widespread availability, predictable and low pricing and suitability for most conversion technologies. In particular, after the typical paper recycling loop, the newspaper waste (NW) could be further valorized as feedstock in biorefinering industry since it still contains up to 70 % polysaccharides. In this study, two different physicochemical methods—ammonia fiber expansion (AFEX) and extractive ammonia (EA) were tested for the pretraetment of NW. Furthermore, based on the previously demonstrated ability of the recombinant enzymes endocellulase rCelStrep, α-l-arabinofuranosidase rPoAbf and its evolved variant rPoAbf F435Y/Y446F to improve the saccharification of different lignocellulosic pretreated biomasses (such as corn stover and Arundo donax), in this study these enzymes were tested for the hydrolysis of pretreated NW, with the aim of valorizing the lignocellulosic fractions of the MSW. In particular, a mixture of purified enzymes containing cellulases, xylanases and accessory hemicellulases, was chosen as reference mix and rCelStrep and rPoAbf or its variant were replaced to EGI and Larb. The results showed that these enzymatic mixes are not suitable for the hydrolysis of NW after AFEX or EA pretreatment. On the other hand, when the enzymes rCelStrep, rPoAbf and rPoAbf F435Y/Y446F were tested for their effect in hydrolysis of pretreated NW by addition to a commercial enzyme mixture, it was shown that the total polysaccharides conversion yield reached 37.32 % for AFEX pretreated NW by adding rPoAbf to the mix whilst the maximum sugars conversion yield for EA pretreated NW was achieved 40.80 % by adding rCelStrep. The maximum glucan conversion yield obtained (45.61 % for EA pretreated NW by adding rCelStrep to the commercial mix) is higher than or comparable to those reported in recent manuscripts adopting hydrolysis conditions similar to those used in this study
Extracting Mushroom Polysaccharides for Intended Benefits of Immunostimulation and Therapeutic Uses
No full textThe use of mushrooms adjuvant in clinical studies to boost immunity and prevent malignancies and viral infections has been promoted by the discovery of bioactive compounds with immunomodulatory capabilities. It is possible to genetically modify mushrooms to produce the desired bioactive compounds in large numbers, which may then be separated for use in both clinical and commercial settings. The purpose of this study is to identify a novel bioactive molecule in Calocybe Indica mushroom sample, which we found to have immunomodulatory properties and potential clinical uses. The research question in action is how to extract and identify polysaccharides and their composition from Calocybe Indica. The methodology used was a hot water extraction set up to extract water-soluble constituents, the concentration of extract, and precipitation of polysaccharides ethanol and centrifugation. Next, to identify the monosaccharide composition, three Thin Layer Chromatography methods were selected, and the Aniline Diphenylamine Phosphoric Acid method produced the best results when tested with sugar samples. Currently, the ongoing experiment involves hydrolyzing the polysaccharides into monomers and conducting a Thin-Layer Chromatography experiment with the hydrolyzed sample to determine the composition of the Calocybe Indica monomers. To further confirm the results of TLC (Thin Layer Chromatography), HPLC (High-Performance Liquid Chromatography) protocol has been developed and is currently being tested. The future work of this project involves optimization of TLC and HPLC protocols, followed by fractionation by gel-filtration chromatography and MALDI analysis of Calocybe Indica extracts.Honors CollegeEngineering Technology, Department o
Optimizing Harvest of Corn Stover Fractions Based on Overall Sugar Yields following AFEX Pretreatment and Enzymatic Hydrolysis
No full textBackground: Corn stover composition changes considerably throughout the growing season and also varies between the various fractions of the plant. These differences can impact optimal pretreatment conditions, enzymatic digestibility and maximum achievable sugar yields in the process of converting lignocellulosics to ethanol. The goal of this project was to determine which combination of corn stover fractions provides the most benefit to the biorefinery in terms of sugar yields and to determine the preferential order in which fractions should be harvested. Ammonia fiber expansion (AFEX) pretreatment, followed by enzymatic hydrolysis, was performed on early and late harvest corn stover fractions (stem, leaf, husk and cob). Sugar yields were used to optimize scenarios for the selective harvest of corn stover assuming 70% or 30% collection of the total available stover.
Results: The optimal AFEX conditions for all stover fractions, regardless of harvest period, were: 1.5 (g NH(3) g(-1) biomass); 60% moisture content (dry-weight basis; dwb), 90 degrees C and 5 min residence time. Enzymatic hydrolysis was conducted using cellulase, beta-glucosidase, and xylanase at 31.3, 41.3, and 3.1 mg g(-1) glucan, respectively. The optimal harvest order for selectively harvested corn stover (SHCS) was husk > leaf > stem > cob. This harvest scenario, combined with optimal AFEX pretreatment conditions, gave a theoretical ethanol yield of 2051 L ha(-1) and 912 L ha(-1) for 70% and 30% corn stover collection, respectively.
Conclusion: Changing the proportion of stover fractions collected had a smaller impact on theoretical ethanol yields (29 - 141 L ha(-1)) compared to the effect of altering pretreatment and enzymatic hydrolysis conditions (150 - 462 L ha(-1)) or harvesting less stover (852 - 1139 L ha(-1)). Resources may be more effectively spent on improving sustainable harvesting, thereby increasing potential ethanol yields per hectare harvested, and optimizing biomass processing rather than focusing on the selective harvest of specific corn stover fractions.Peer reviewed
'Cradle-to-grave' assessment of existing lignocellulose pretreatment technologies
No full textPretreatment is considered to be a central unit process in a biorefinery to convert lignocellulosic biomass into fuels and chemicals, affecting all other operations in the process. A variety of technologies to pretreat lignocellulosic biomass are available today, which encompass a wide range of physical, chemical, and biological based processes. Among these, chemical based pretreatments are considered to be the most promising for future biorefineries. However, several key criteria regarding technical, economical, and environmental considerations should be critically analyzed when adapting these technologies for the nascent biorefinery industry. This review will discuss the most important pretreatment methods available today and will highlight key criteria for the development of a future ideal pretreatment.Peer reviewed
Integrated Process for Red Algae Culturing and Processing High Value Algal Products: EPS & CPS, B-PE and PUFAs
No full textThe global demand for algae and algal products are increasing over years. However, the cost for current commercial processing and purifying of algae products for good biological activities is quite high. This project aims to develop an integrated process to increase the Exopolysaccharide (EPS) and Capsular polysaccharide (CPS) yield and produce other high value co-products (B-phycoerythrin(B-PE), and poly-unsaturated fatty acids (PUFAs)) from red algae. The two-state culture process with white and green light is promising for high yield of EPS. The EPS is successful extracted by the acid precipitate method for commercial algae water. The enzyme-based extraction with the combination of alpha- and gluco-amylase enzyme yield much more B-PE compared to other reported methods. PUFA extraction by low-cost solvent helps reduce the production cost and promises for recycle of the water. This integrated process is not only promising to produce algal products at low cost but also recycle processing water for subsequent algae cultivation benefiting environment.Chemical and Biomolecular Engineering, William A. Brookshire Department ofHonors Colleg
Fractionation of Mushroom Stems to Various Bioactive Molecules and Processing Chitin to Hydrogel for Wound Healing Application
No full textOyster Mushrooms have several medicinally active ingredients, such as polysaccharides and vitamins, and their extractives are widely used as nutritional supplements. After the oyster mushrooms are produced, most of the stems are discarded since they are tough to cook and usually end up in landfills. This research is about fractionating mushrooms stems to various bioactive molecules using a combination of re-usable organic solvents and enzymes. A mass balance was completed to quantify various components such as beta-glucans, lipids, vitamins, polyphenols, proteins, and chitin. The mass of each component was identified by measuring the dry weight of mushroom powder left after the extraction. The extracted components were further subjected to spectroscopy [FT-Infrared (FT-IR), powder X-ray diffraction, GC-MS, UV-Visible HPLC] analysis to confirm their structure and composition. The mushroom chitin could be de-acetylated to chitosan and converted to methacrylate chitosan by chemical processing. This chitosan derivative could be crosslinked with the help of the photo initiator Irgacure 2959 and UV light to produce a hydrogel and 3D printed to bio patches used for wound dressing applications. To demonstrate the proof of concept, we took the shrimp shell chitosan and produced methacrylate chitosan and cross-linked to produce hydrogels. We confirmed the reaction by performing FT-IR analysis at different stages. Overall, this research work provides a foundation for converting wasted mushroom stems to chitin which could be further processed to produce chitosan hydrogel bio patches used for wound dressing.Engineering Technology, Department ofHonors CollegeBiology and Biochemistry, Department o
Producing Peptostreptococcus Magnus Protein L and binding domain using E. Coli
No full textProtein L is an antibody-binding protein that interacts with the light chains. There are multiple domains within the protein and there could be a possibility to increase the binding capabilities. The area of protein L that binds to the antibody comprises several domains, the focus is the B1 domain. The protein cannot be produced on its own, it must be produced using a host organism. The host organism is BL21 and this was picked because it has the opportunity to allow proteins to grow due to the absence of proteases that would usually break down proteins. The next factor taken into consideration was the plasmid that would contain the gene of interest, the plasmid chosen was pET 28a, and the plasmid was chosen based on its antibiotic resistance to kanamycin, which would allow for the selection process to isolate the plasmids possibly containing the gene of interest. Lastly, the cut enzymes were chosen because of their location in contrast to the 6x His Tag. This project will be expanded into future processes such as the mass production of the protein and purifying the protein even further.Engineering Technology, Department ofHonors Colleg
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