{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/30787"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/30787","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Evaluating bacterial cell immobilization matrices for use in a biosensor","abstract":"A biosensor is proposed that contains bacteria that naturally effluxes potassium ions when threatened by electrophilic species. Pseudomonas aeruginosa is an activated sludge isolate and possesses the characteristic potassium efflux response. It has been immobilized in calcium alginate beads, photopolymer disks, and a thermally reversible gel in order to ultimately incorporate the immobilized system into a functional biosensor. The potassium efflux and cell viability were measured in the immobilized matrices. Wastewater treatment is of utmost importance; however, processes are easily upset. Upsets can be caused by various electrophiles found in the environment, and can cause serious health effects to people or the environment downstream from an upset. Electrophiles can cause the activated sludge in wastewater treatment facilities to deflocculate, and untreated water can be lost downstream. Devising a detection system for proactively sensing electrophiles prior to an upset is an important complementary goal. Immobilization systems have been evaluated including photopolymer coated alginate beads and sol gel coated alginate beads. The thermally reversible gel, NIPA-co-AAc (N-isopropylacrylamide-co-acrylic acid), shows promise as an immobilization matrix for the bacteria; however its high lower critical solution temperature (LCST) of ~33oC is problematic for typical, ambient applications. Another thermally reversible copolymer, N-isopropylacrylamide-co-N-acryloyl-6-amino caproic acid (NIPA-co-AcACA) was synthesized; however, it did not form a continuous matrix; making it useless as an immobilization scheme for biosensors. Alginate beads fall apart easily in bacteria media, but are structurally stable in potassium solutions. Cells immobilized in alginate beads seemed to efflux four times less potassium than did planktonic controls, while cells in thermally reversible gels effluxed a comparable amount of potassium as planktonic controls. This result may indicate a tighter matrix around the alginate immobilized cells, not allowing proper diffusion of potassium out of the matrix.","abstract_html":"A biosensor is proposed that contains bacteria that naturally effluxes potassium ions when threatened by electrophilic species. Pseudomonas aeruginosa is an activated sludge isolate and possesses the characteristic potassium efflux response. It has been immobilized in calcium alginate beads, photopolymer disks, and a thermally reversible gel in order to ultimately incorporate the immobilized system into a functional biosensor. The potassium efflux and cell viability were measured in the immobilized matrices. Wastewater treatment is of utmost importance; however, processes are easily upset. Upsets can be caused by various electrophiles found in the environment, and can cause serious health effects to people or the environment downstream from an upset. Electrophiles can cause the activated sludge in wastewater treatment facilities to deflocculate, and untreated water can be lost downstream. Devising a detection system for proactively sensing electrophiles prior to an upset is an important complementary goal. Immobilization systems have been evaluated including photopolymer coated alginate beads and sol gel coated alginate beads. The thermally reversible gel, NIPA-co-AAc (N-isopropylacrylamide-co-acrylic acid), shows promise as an immobilization matrix for the bacteria; however its high lower critical solution temperature (LCST) of ~33oC is problematic for typical, ambient applications. Another thermally reversible copolymer, N-isopropylacrylamide-co-N-acryloyl-6-amino caproic acid (NIPA-co-AcACA) was synthesized; however, it did not form a continuous matrix; making it useless as an immobilization scheme for biosensors. Alginate beads fall apart easily in bacteria media, but are structurally stable in potassium solutions. Cells immobilized in alginate beads seemed to efflux four times less potassium than did planktonic controls, while cells in thermally reversible gels effluxed a comparable amount of potassium as planktonic controls. This result may indicate a tighter matrix around the alginate immobilized cells, not allowing proper diffusion of potassium out of the matrix.","abstract_has_math":false,"creators":["Fleming, Dara Lynn"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Materials Science and Engineering","degree_department":"Materials Science and Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Love, Brian J."],"committee_members":["Love, Nancy G.","Meehan, Kathleen"],"year":2004,"date_issued":"2004-12-07","date_published":"2004-12-07","updated_at":"2026-07-22T22:19:29Z","subjects":["alginate","NIPA","photopolymer","bacterial immobilization"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-01032005-074039"],"render_values":[{"text":"etd-01032005-074039","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/30787","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Love, Brian J."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Love, Nancy G.","Meehan, Kathleen"]},{"key":"dc:contributor.department","label":"Department","values":["Materials Science and Engineering"]},{"key":"dc:creator","label":"Author","values":["Fleming, Dara Lynn"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:30:02Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:30:02Z","2005-01-07"]},{"key":"dc:date.issued","label":"Date","values":["2004-12-07"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science and Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["alginate","NIPA","photopolymer","bacterial immobilization"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-01032005-074039"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/30787"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A biosensor is proposed that contains bacteria that naturally effluxes potassium ions when threatened by electrophilic species. Pseudomonas aeruginosa is an activated sludge isolate and possesses the characteristic potassium efflux response. It has been immobilized in calcium alginate beads, photopolymer disks, and a thermally reversible gel in order to ultimately incorporate the immobilized system into a functional biosensor. The potassium efflux and cell viability were measured in the immobilized matrices. Wastewater treatment is of utmost importance; however, processes are easily upset. Upsets can be caused by various electrophiles found in the environment, and can cause serious health effects to people or the environment downstream from an upset. Electrophiles can cause the activated sludge in wastewater treatment facilities to deflocculate, and untreated water can be lost downstream. Devising a detection system for proactively sensing electrophiles prior to an upset is an important complementary goal. Immobilization systems have been evaluated including photopolymer coated alginate beads and sol gel coated alginate beads. The thermally reversible gel, NIPA-co-AAc (N-isopropylacrylamide-co-acrylic acid), shows promise as an immobilization matrix for the bacteria; however its high lower critical solution temperature (LCST) of ~33oC is problematic for typical, ambient applications. Another thermally reversible copolymer, N-isopropylacrylamide-co-N-acryloyl-6-amino caproic acid (NIPA-co-AcACA) was synthesized; however, it did not form a continuous matrix; making it useless as an immobilization scheme for biosensors. Alginate beads fall apart easily in bacteria media, but are structurally stable in potassium solutions. Cells immobilized in alginate beads seemed to efflux four times less potassium than did planktonic controls, while cells in thermally reversible gels effluxed a comparable amount of potassium as planktonic controls. This result may indicate a tighter matrix around the alginate immobilized cells, not allowing proper diffusion of potassium out of the matrix."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Evaluating bacterial cell immobilization matrices for use in a biosensor"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Love, Brian J."],"dc:contributor.committeemember":["Love, Nancy G.","Meehan, Kathleen"],"dc:contributor.department":["Materials Science and Engineering"],"dc:creator":["Fleming, Dara Lynn"],"dc:date.accessioned":["2014-03-14T20:30:02Z"],"dc:date.available":["2014-03-14T20:30:02Z","2005-01-07"],"dc:date.issued":["2004-12-07"],"dc:description.abstract":["A biosensor is proposed that contains bacteria that naturally effluxes potassium ions when threatened by electrophilic species. Pseudomonas aeruginosa is an activated sludge isolate and possesses the characteristic potassium efflux response. It has been immobilized in calcium alginate beads, photopolymer disks, and a thermally reversible gel in order to ultimately incorporate the immobilized system into a functional biosensor. The potassium efflux and cell viability were measured in the immobilized matrices. Wastewater treatment is of utmost importance; however, processes are easily upset. Upsets can be caused by various electrophiles found in the environment, and can cause serious health effects to people or the environment downstream from an upset. Electrophiles can cause the activated sludge in wastewater treatment facilities to deflocculate, and untreated water can be lost downstream. Devising a detection system for proactively sensing electrophiles prior to an upset is an important complementary goal. Immobilization systems have been evaluated including photopolymer coated alginate beads and sol gel coated alginate beads. The thermally reversible gel, NIPA-co-AAc (N-isopropylacrylamide-co-acrylic acid), shows promise as an immobilization matrix for the bacteria; however its high lower critical solution temperature (LCST) of ~33oC is problematic for typical, ambient applications. Another thermally reversible copolymer, N-isopropylacrylamide-co-N-acryloyl-6-amino caproic acid (NIPA-co-AcACA) was synthesized; however, it did not form a continuous matrix; making it useless as an immobilization scheme for biosensors. Alginate beads fall apart easily in bacteria media, but are structurally stable in potassium solutions. Cells immobilized in alginate beads seemed to efflux four times less potassium than did planktonic controls, while cells in thermally reversible gels effluxed a comparable amount of potassium as planktonic controls. This result may indicate a tighter matrix around the alginate immobilized cells, not allowing proper diffusion of potassium out of the matrix."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-01032005-074039"],"dc:identifier.uri":["http://hdl.handle.net/10919/30787"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["alginate","NIPA","photopolymer","bacterial immobilization"],"dc:title":["Evaluating bacterial cell immobilization matrices for use in a biosensor"],"dc:type":["Thesis"],"thesis:degree_discipline":["Materials Science and Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:29Z"}