U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Bioenergy Research: Peoria, IL
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    NCAUR Homepage
                    About BER
                        Mission Statement
                                    Strategic Goals
                                    Specialized Research ResourcesSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area Peoria, Illinois National Center for Agricultural Utilization Research Bioenergy Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Research Project: Technologies for Improving Process Efficiencies in Biomass Refineries Location:
                                Bioenergy Research Title:   Author  item
                                            Bowman, Michaelitem
                                            Dien, Bruceitem
                                            Vermillion, Karlitem
                                            Mertens, Jeffrey
  Submitted to: Carbohydrate Research
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 1/23/2015
                                    Publication  Date: 4/30/2015
                                    Publication URL: http://handle.nal.usda.gov/10113/60608Citation: Bowman, M.J., Dien, B.S., Vermillion, K.E., Mertens, J.A. 2015. Isolation and characterization of unhydrolyzed oligosaccharides from switchgrass (Panicum virgatum, L.) xylan after exhaustive enzymatic treatment with commercial enzyme preparations. Carbohydrate Research. 407:42-50.Interpretive Summary: Switchgrass is a perennial grass presently used as for forage and being developed as a bioenergy crop for conversion to biofuels. Up to 30% of switchgrass cell wall associated carbohydrates are xylan. Previously, switchgrass xylan structural features that have not been previously reported were identified in three cultivars. In the current study, these structures were not readily hydrolyzed by commercial enzymes demonstrating that the chemical bond contained in these structures is partially responsible for xylan recalcitrance. Identification of the presence of this variation is relevant to commercial enzyme producers interested in designing improved enzymatic combinations to more effectively hydrolyze xylan to improve bioconversion yields.
                                Technical Abstract: Switchgrass (Panicum virgatum, L.) is a potential renewable source of carbohydrates for use in microbial conversion to biofuels. Xylan comprises approximately 30% of the switchgrass cell wall. To understand the limitations of commercial enzyme mixtures, alkali-extracted, isolated switchgrass xylan was hydrolyzed by the action of two commercial enzyme cocktails, in the presence and absence of an additional alpha-arabinofuranosidase enzyme. The two most abundant enzymatic digestion products from each commercial enzyme treatment were separated and characterized by LC-MSn, linkage analysis, and NMR. The most abundant oligosaccharide from each commercial cocktail was susceptible to hydrolysis when supplemented with a GH62 alpha-arabinofuranosidase enzyme; further characterization confirmed the presence of (1->3)-alpha-arabinose linkages. These results demonstrate the lack of the required selectivity for arabinose-containing substrates in the commercial enzyme preparations tested. One product from each condition remained intact and was found to contain (1->2)-beta-xylose-(1->3)-alpha-arabinose side chains; this linkage acts as a source of oligosaccharide recalcitrance.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov