{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/34403"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/34403","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Optimizing pentose sugar utilization in Escherichia coli for the production of biofuels","abstract":"The hydrolysis of biomass yields a sugar mixture consisting mainly of glucose, arabinose and xylose. Effective metabolism of all sugars in biomass by a microorganism is regarded as essential for commercial biofuel production. However, two of the major challenges that we are currently faced with are the transport of sugars into the microorganism and the co-utilization of these sugars once they are in the cell. In order to engineer simultaneous multiple sugar utilization in Escherichia coli, a better understanding of the pentose sugar pathways is required. In this work, we have investigated the transport of sugars and the regulation of the sugar metabolic pathways within E. coli to engineer a strain most efficient in producing biofuels. While extensive research has been carried out to examine the transport mechanisms of sugars into the cell, this research shows that in addition to transporters that pump sugars into the cell, a number of proteins that pump sugars out of the cell are also expressed by E. coli. Using genetic approaches, we have demonstrated that by either deleting or overexpressing these efflux transporters we can respectively increase or decrease the uptake of pentose sugars, namely arabinose and xylose, which are abundantly present in the hemicellulose of biomass. In addition to examining transport mechanisms, this work has also focused on studying and controlling the metabolism of the pentose sugars. By using a novel targeted approach, we can utilize constitutive promoters and chromosomal integration to control the expression of certain metabolic genes, while relieving repression effects. This enables us to regulate the metabolism of pentose sugars such as xylose that are utilized by the cell less efficiently and allows for simultaneous metabolism of sugars, hence leading to a more efficient biofuel production process.","abstract_html":"The hydrolysis of biomass yields a sugar mixture consisting mainly of glucose, arabinose and xylose. Effective metabolism of all sugars in biomass by a microorganism is regarded as essential for commercial biofuel production. However, two of the major challenges that we are currently faced with are the transport of sugars into the microorganism and the co-utilization of these sugars once they are in the cell. In order to engineer simultaneous multiple sugar utilization in Escherichia coli, a better understanding of the pentose sugar pathways is required. In this work, we have investigated the transport of sugars and the regulation of the sugar metabolic pathways within E. coli to engineer a strain most efficient in producing biofuels. While extensive research has been carried out to examine the transport mechanisms of sugars into the cell, this research shows that in addition to transporters that pump sugars into the cell, a number of proteins that pump sugars out of the cell are also expressed by E. coli. Using genetic approaches, we have demonstrated that by either deleting or overexpressing these efflux transporters we can respectively increase or decrease the uptake of pentose sugars, namely arabinose and xylose, which are abundantly present in the hemicellulose of biomass. In addition to examining transport mechanisms, this work has also focused on studying and controlling the metabolism of the pentose sugars. By using a novel targeted approach, we can utilize constitutive promoters and chromosomal integration to control the expression of certain metabolic genes, while relieving repression effects. This enables us to regulate the metabolism of pentose sugars such as xylose that are utilized by the cell less efficiently and allows for simultaneous metabolism of sugars, hence leading to a more efficient biofuel production process.","abstract_has_math":false,"creators":["Koita, Khushnuma"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemical Engineering","degree_department":null,"school":null,"contributors":["Rao, Christopher V.","Pack, Daniel W.","Zhao, Huimin","Bhalerao, Kaustubh"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-09-18T21:15:15Z","date_published":"2012-09-18T21:15:15Z","updated_at":"2026-07-22T22:25:31Z","subjects":["biofuels","arabinose efflux","pentose transport","xylose metabolism","strain engineering"],"languages":["en"],"rights":["Copyright 2012 Khushnuma Koita"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/34403","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Rao, Christopher V.","Pack, Daniel W.","Zhao, Huimin","Bhalerao, Kaustubh"]},{"key":"dc:creator","label":"Author","values":["Koita, Khushnuma"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-09-18T21:15:15Z","2012-08"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["biofuels","arabinose efflux","pentose transport","xylose metabolism","strain engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2012 Khushnuma Koita"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/34403"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The hydrolysis of biomass yields a sugar mixture consisting mainly of glucose, arabinose and xylose. Effective metabolism of all sugars in biomass by a microorganism is regarded as essential for commercial biofuel production. However, two of the major challenges that we are currently faced with are the transport of sugars into the microorganism and the co-utilization of these sugars once they are in the cell. In order to engineer simultaneous multiple sugar utilization in Escherichia coli, a better understanding of the pentose sugar pathways is required. In this work, we have investigated the transport of sugars and the regulation of the sugar metabolic pathways within E. coli to engineer a strain most efficient in producing biofuels. While extensive research has been carried out to examine the transport mechanisms of sugars into the cell, this research shows that in addition to transporters that pump sugars into the cell, a number of proteins that pump sugars out of the cell are also expressed by E. coli. Using genetic approaches, we have demonstrated that by either deleting or overexpressing these efflux transporters we can respectively increase or decrease the uptake of pentose sugars, namely arabinose and xylose, which are abundantly present in the hemicellulose of biomass. In addition to examining transport mechanisms, this work has also focused on studying and controlling the metabolism of the pentose sugars. By using a novel targeted approach, we can utilize constitutive promoters and chromosomal integration to control the expression of certain metabolic genes, while relieving repression effects. This enables us to regulate the metabolism of pentose sugars such as xylose that are utilized by the cell less efficiently and allows for simultaneous metabolism of sugars, hence leading to a more efficient biofuel production process.","Item withdrawn by Rebecca Bryant (rabryant@illinois.edu) on 2012-07-09T18:43:27Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 3 Koita_Khushnuma.pdf: 3755884 bytes, checksum: 92b3cb47389e1b85969744706c84634d (MD5) Koita_Khushnuma.docx: 3542793 bytes, checksum: 768847c9d11f1e6196e476075c275a83 (MD5) Koita_Khushnuma.pdf: 3771804 bytes, checksum: e7d8fccd731f3c7880e0eb95270a32e8 (MD5)","Made available in DSpace on 2012-09-18T21:15:15Z (GMT). No. of bitstreams: 3 Koita_Khushnuma.pdf: 3767618 bytes, checksum: 013e7da485e3c8752fcccaa9d11c30cf (MD5) Koita_Khushnuma.docx: 3532475 bytes, checksum: 3c4bbf2be192479f5d9e7213f06e7402 (MD5) license.txt: 4064 bytes, checksum: c6c1da15dc60e4697edc4f8a7177c7fc (MD5)"]},{"key":"dc:title","label":"Title","values":["Optimizing pentose sugar utilization in Escherichia coli for the production of biofuels"]}]}],"canonical_facts":{"dc:contributor":["Rao, Christopher V.","Pack, Daniel W.","Zhao, Huimin","Bhalerao, Kaustubh"],"dc:creator":["Koita, Khushnuma"],"dc:date":["2012-09-18T21:15:15Z","2012-08"],"dc:description":["The hydrolysis of biomass yields a sugar mixture consisting mainly of glucose, arabinose and xylose. Effective metabolism of all sugars in biomass by a microorganism is regarded as essential for commercial biofuel production. However, two of the major challenges that we are currently faced with are the transport of sugars into the microorganism and the co-utilization of these sugars once they are in the cell. In order to engineer simultaneous multiple sugar utilization in Escherichia coli, a better understanding of the pentose sugar pathways is required. In this work, we have investigated the transport of sugars and the regulation of the sugar metabolic pathways within E. coli to engineer a strain most efficient in producing biofuels. While extensive research has been carried out to examine the transport mechanisms of sugars into the cell, this research shows that in addition to transporters that pump sugars into the cell, a number of proteins that pump sugars out of the cell are also expressed by E. coli. Using genetic approaches, we have demonstrated that by either deleting or overexpressing these efflux transporters we can respectively increase or decrease the uptake of pentose sugars, namely arabinose and xylose, which are abundantly present in the hemicellulose of biomass. In addition to examining transport mechanisms, this work has also focused on studying and controlling the metabolism of the pentose sugars. By using a novel targeted approach, we can utilize constitutive promoters and chromosomal integration to control the expression of certain metabolic genes, while relieving repression effects. This enables us to regulate the metabolism of pentose sugars such as xylose that are utilized by the cell less efficiently and allows for simultaneous metabolism of sugars, hence leading to a more efficient biofuel production process.","Item withdrawn by Rebecca Bryant (rabryant@illinois.edu) on 2012-07-09T18:43:27Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 3 Koita_Khushnuma.pdf: 3755884 bytes, checksum: 92b3cb47389e1b85969744706c84634d (MD5) Koita_Khushnuma.docx: 3542793 bytes, checksum: 768847c9d11f1e6196e476075c275a83 (MD5) Koita_Khushnuma.pdf: 3771804 bytes, checksum: e7d8fccd731f3c7880e0eb95270a32e8 (MD5)","Made available in DSpace on 2012-09-18T21:15:15Z (GMT). No. of bitstreams: 3 Koita_Khushnuma.pdf: 3767618 bytes, checksum: 013e7da485e3c8752fcccaa9d11c30cf (MD5) Koita_Khushnuma.docx: 3532475 bytes, checksum: 3c4bbf2be192479f5d9e7213f06e7402 (MD5) license.txt: 4064 bytes, checksum: c6c1da15dc60e4697edc4f8a7177c7fc (MD5)"],"dc:identifier":["http://hdl.handle.net/2142/34403"],"dc:language":["en"],"dc:rights":["Copyright 2012 Khushnuma Koita"],"dc:subject":["biofuels","arabinose efflux","pentose transport","xylose metabolism","strain engineering"],"dc:title":["Optimizing pentose sugar utilization in Escherichia coli for the production of biofuels"],"thesis:degree_discipline":["Chemical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:31Z"}