{"id":{"repo_id":"wlv","oai_identifier":"oai:wlv.openrepository.com:2436/626059"},"canonical_url":"https://search.dev.ndltd.org/etd/wlv/oai:wlv.openrepository.com:2436/626059","repository":{"repo_id":"wlv","name":"University of Wolverhampton","base_url":"https://wlv.openrepository.com/server/oai/request"},"display":{"title":"The role of γ-polyglutamic acid in a circular economy: cost-effective production and wide-ranging applications of a bio-derived, biodegradable, and nonimmunogenic biomaterial","abstract":"Microbial products have long been investigated for their potential as backbones of biodegradable constructs. Poly-γ-glutamic acid (γ-PGA) is an anionic pseudo polypeptide produced by several microorganisms, especially members of the Bacillus species. γ-PGA is synthesised through several enzymes and complexes which racemise and polymerise L- glutamic acid or D- glutamic acid. This non-toxic microbial product can have variable viscosity, is water soluble, biodegradable, and non-immunogenic. The scope of this work was to investigate the effect of substrate components on the chemical and physical characteristics of γ-PGA (Chapter 3). To increase cost-effectiveness and adoption of γ-PGA, further investigation into the effect of different complex media on the yields and composition of resulting material was evaluated (Chapter 3). Subsequently, the potential of γ-PGA from standard cultivation media and complex media as a substitute for hyaluronic acid in cosmetics was evaluated (Chapter 4). UV protective effects of γ-PGA and seaweed rich, crude γ-PGA extracts was assessed and quantified (Chapter 4) and its potential interaction with skin keratinocytes was quantified. γ-PGA ability to interact with ions was assessed in the context of dental demineralisation and prevention thereof (Chapter 5). Potential protein-protein interaction of γ-PGA with monomeric and aggregate forms of alpha synuclein, was assessed in the context of Parkinson disease pathology (Chapter 6). Ultimately the inflammatory response of γ-PGA and γ-PGA-based composites (whey protein isolate- γ-PGA) were also evaluated (Chapter 7). This investigation found the ability of specific ions (Mn2+ and NaCl) to affect the yields and properties of γ-PGA in both standard (GS/Medium E) and complex media (seaweed based). γ-PGA synthesised from complex media could be purified through membrane-based separation technologies although further optimisation is required to selectively removed undesirable impurities. Although commercial γ-PGA was not found to have any UV protection capacity, standard media γ-PGA had some UV protective capacity with complex media derived γ-PGA having the highest protection. No γ-PGA was found to have any detrimental effect on tested HaCaT keratinocyte cells. Both standard and complex media derived γ-PGA did suggest ability to physically bind to components of hydroxyapatite, component of the tooth enamel. Further, our data suggests that γ-PGA is able to co-localise with Parkinson disease specific alpha synuclein aggregates and disrupt further addition of monomeric components onto pre-formed fibrils. In addition, both γ-PGA and pre-formed fibrils of alpha synuclein were shown to be internalised within astrocyte cytoplasm when introduced in the media. Ultimately, γ-PGA addition has shown to significantly decrease inflammatory status of osteoblasts and astrocytes in vitro. This work explores innovative applications of γ-PGA, synthesised from complex media. Fundamental properties of γ-PGA that can be obtained in standard (GS media, Medium E and similar) and complex media have been evaluated for comprehensive understanding on property-application relationship and its potential scale up applications. This work elaborates on how γ-PGA could be the key to the next generation of microbial derived bioproducts.","abstract_html":"Microbial products have long been investigated for their potential as backbones of biodegradable constructs. Poly-γ-glutamic acid (γ-PGA) is an anionic pseudo polypeptide produced by several microorganisms, especially members of the Bacillus species. γ-PGA is synthesised through several enzymes and complexes which racemise and polymerise L- glutamic acid or D- glutamic acid. This non-toxic microbial product can have variable viscosity, is water soluble, biodegradable, and non-immunogenic. The scope of this work was to investigate the effect of substrate components on the chemical and physical characteristics of γ-PGA (Chapter 3). To increase cost-effectiveness and adoption of γ-PGA, further investigation into the effect of different complex media on the yields and composition of resulting material was evaluated (Chapter 3). Subsequently, the potential of γ-PGA from standard cultivation media and complex media as a substitute for hyaluronic acid in cosmetics was evaluated (Chapter 4). UV protective effects of γ-PGA and seaweed rich, crude γ-PGA extracts was assessed and quantified (Chapter 4) and its potential interaction with skin keratinocytes was quantified. γ-PGA ability to interact with ions was assessed in the context of dental demineralisation and prevention thereof (Chapter 5). Potential protein-protein interaction of γ-PGA with monomeric and aggregate forms of alpha synuclein, was assessed in the context of Parkinson disease pathology (Chapter 6). Ultimately the inflammatory response of γ-PGA and γ-PGA-based composites (whey protein isolate- γ-PGA) were also evaluated (Chapter 7). This investigation found the ability of specific ions (Mn2+ and NaCl) to affect the yields and properties of γ-PGA in both standard (GS/Medium E) and complex media (seaweed based). γ-PGA synthesised from complex media could be purified through membrane-based separation technologies although further optimisation is required to selectively removed undesirable impurities. Although commercial γ-PGA was not found to have any UV protection capacity, standard media γ-PGA had some UV protective capacity with complex media derived γ-PGA having the highest protection. No γ-PGA was found to have any detrimental effect on tested HaCaT keratinocyte cells. Both standard and complex media derived γ-PGA did suggest ability to physically bind to components of hydroxyapatite, component of the tooth enamel. Further, our data suggests that γ-PGA is able to co-localise with Parkinson disease specific alpha synuclein aggregates and disrupt further addition of monomeric components onto pre-formed fibrils. In addition, both γ-PGA and pre-formed fibrils of alpha synuclein were shown to be internalised within astrocyte cytoplasm when introduced in the media. Ultimately, γ-PGA addition has shown to significantly decrease inflammatory status of osteoblasts and astrocytes in vitro. This work explores innovative applications of γ-PGA, synthesised from complex media. Fundamental properties of γ-PGA that can be obtained in standard (GS media, Medium E and similar) and complex media have been evaluated for comprehensive understanding on property-application relationship and its potential scale up applications. This work elaborates on how γ-PGA could be the key to the next generation of microbial derived bioproducts.","abstract_has_math":false,"creators":["Parati, Mattia"],"institution":"University of Wolverhampton","degree_name":"PhD","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Radecka, Izabela"],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025","date_published":"2025","updated_at":"2026-07-24T06:09:41Z","subjects":["biotechnology","biopolymer","microbial biotechnology","biomaterials","circular bioprocesses"],"languages":[],"rights":[],"rights_urls":["https://wlv.openrepository.com/bitstreams/36e20821-518b-4f53-9e39-8889761afd82/download"],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Radecka, Izabela"]},{"key":"dc:contributor.sponsor","label":"Sponsor","values":["The Biotechnology and Biological Sciences Research Council (Swindon, GB), part of grant number: 5749484. 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UV protective effects of γ-PGA and seaweed rich, crude γ-PGA extracts was assessed and quantified (Chapter 4) and its potential interaction with skin keratinocytes was quantified. γ-PGA ability to interact with ions was assessed in the context of dental demineralisation and prevention thereof (Chapter 5). Potential protein-protein interaction of γ-PGA with monomeric and aggregate forms of alpha synuclein, was assessed in the context of Parkinson disease pathology (Chapter 6). Ultimately the inflammatory response of γ-PGA and γ-PGA-based composites (whey protein isolate- γ-PGA) were also evaluated (Chapter 7). This investigation found the ability of specific ions (Mn2+ and NaCl) to affect the yields and properties of γ-PGA in both standard (GS/Medium E) and complex media (seaweed based). γ-PGA synthesised from complex media could be purified through membrane-based separation technologies although further optimisation is required to selectively removed undesirable impurities. Although commercial γ-PGA was not found to have any UV protection capacity, standard media γ-PGA had some UV protective capacity with complex media derived γ-PGA having the highest protection. No γ-PGA was found to have any detrimental effect on tested HaCaT keratinocyte cells. Both standard and complex media derived γ-PGA did suggest ability to physically bind to components of hydroxyapatite, component of the tooth enamel. Further, our data suggests that γ-PGA is able to co-localise with Parkinson disease specific alpha synuclein aggregates and disrupt further addition of monomeric components onto pre-formed fibrils. In addition, both γ-PGA and pre-formed fibrils of alpha synuclein were shown to be internalised within astrocyte cytoplasm when introduced in the media. Ultimately, γ-PGA addition has shown to significantly decrease inflammatory status of osteoblasts and astrocytes in vitro. This work explores innovative applications of γ-PGA, synthesised from complex media. Fundamental properties of γ-PGA that can be obtained in standard (GS media, Medium E and similar) and complex media have been evaluated for comprehensive understanding on property-application relationship and its potential scale up applications. This work elaborates on how γ-PGA could be the key to the next generation of microbial derived bioproducts."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["2514fbdcd1bc16cf6224784062f66e93","0d0d727b2390e51aad0b3f79741fe3bd","79cc9c558089c2829a28510d0296eb06"]},{"key":"dc:title","label":"Title","values":["The role of γ-polyglutamic acid in a circular economy: cost-effective production and wide-ranging applications of a bio-derived, biodegradable, and nonimmunogenic biomaterial"]}]}],"canonical_facts":{"dc:contributor.advisor":["Radecka, Izabela"],"dc:contributor.sponsor":["The Biotechnology and Biological Sciences Research Council (Swindon, GB), part of grant number: 5749484. 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To increase cost-effectiveness and adoption of γ-PGA, further investigation into the effect of different complex media on the yields and composition of resulting material was evaluated (Chapter 3). Subsequently, the potential of γ-PGA from standard cultivation media and complex media as a substitute for hyaluronic acid in cosmetics was evaluated (Chapter 4). UV protective effects of γ-PGA and seaweed rich, crude γ-PGA extracts was assessed and quantified (Chapter 4) and its potential interaction with skin keratinocytes was quantified. γ-PGA ability to interact with ions was assessed in the context of dental demineralisation and prevention thereof (Chapter 5). Potential protein-protein interaction of γ-PGA with monomeric and aggregate forms of alpha synuclein, was assessed in the context of Parkinson disease pathology (Chapter 6). Ultimately the inflammatory response of γ-PGA and γ-PGA-based composites (whey protein isolate- γ-PGA) were also evaluated (Chapter 7). This investigation found the ability of specific ions (Mn2+ and NaCl) to affect the yields and properties of γ-PGA in both standard (GS/Medium E) and complex media (seaweed based). γ-PGA synthesised from complex media could be purified through membrane-based separation technologies although further optimisation is required to selectively removed undesirable impurities. Although commercial γ-PGA was not found to have any UV protection capacity, standard media γ-PGA had some UV protective capacity with complex media derived γ-PGA having the highest protection. No γ-PGA was found to have any detrimental effect on tested HaCaT keratinocyte cells. Both standard and complex media derived γ-PGA did suggest ability to physically bind to components of hydroxyapatite, component of the tooth enamel. Further, our data suggests that γ-PGA is able to co-localise with Parkinson disease specific alpha synuclein aggregates and disrupt further addition of monomeric components onto pre-formed fibrils. In addition, both γ-PGA and pre-formed fibrils of alpha synuclein were shown to be internalised within astrocyte cytoplasm when introduced in the media. Ultimately, γ-PGA addition has shown to significantly decrease inflammatory status of osteoblasts and astrocytes in vitro. This work explores innovative applications of γ-PGA, synthesised from complex media. Fundamental properties of γ-PGA that can be obtained in standard (GS media, Medium E and similar) and complex media have been evaluated for comprehensive understanding on property-application relationship and its potential scale up applications. 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