Antimicrobial potential of Clostridium and closely related species derived from farm environmental samples : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Manawatū, New Zealand

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dc.confidentialEmbargo : Noen_US
dc.contributor.advisorFlint, Steve
dc.contributor.authorWeligala Pahalagedara, Amila Srilal Nawarathna
dc.date.accessioned2021-12-08T20:18:27Z
dc.date.accessioned2022-06-10T00:12:58Z
dc.date.available2021-12-08T20:18:27Z
dc.date.available2022-06-10T00:12:58Z
dc.date.issued2021
dc.description.abstractThe exploration of antimicrobial compounds from natural sources such as bacteria, has been fast tracked by the development of antimicrobial resistance to existing antimicrobials and the increasing consumer demand for natural food preservatives. So far, antimicrobial discovery has been biased towards aerobic and facultative anaerobic bacteria and fungi. Strict anaerobes such as Clostridium species have not been thoroughly investigated for their antimicrobial potential. The objective of the current study was to evaluate the antimicrobial potential of Clostridium and closely related species against bacteria associated with food spoilage, food safety, and human health. Tests on culture media inoculated with Clostridium and closely related species from farm samples (conditioned media/CMs) showed various degrees of antimicrobial activity. Farm 4 soil conditioned medium (F4SCM) showed potential for further investigation in the search for potent antimicrobials with its promising antimicrobial activity. Bacterial isolates (FS01, FS2.2, FS03, and FS04) belonging to Clostridium and closely related spp. associated with F4SCM showed antimicrobial potential as evident by culture-based and genome-based methods. F4SCM and FS03CM (CM prepared from FS03) metabolomes showed the presence of several putative antimicrobial metabolites. Among them, 2-hydroxyisocaproic acid (HICA) showed antimicrobial activity against a wide range of bacteria associated with food spoilage and safety indicating its potential as a bio-preservative agent in food products. The cell cytoplasmic membrane is a likely target of the HICA’s antimicrobial activity. Overall, this study demonstrates that anaerobic bacterial species, Clostridium, and closely related species can produce antimicrobial metabolites, that have potential applications in food preservation and human health. The knowledge obtained in this study will help future investigations to identify and characterize antimicrobials from these Clostridium and closely related bacteria and expands the understanding of the potential to produce antimicrobial compounds from the genus Clostridium and closely related species.en_US
dc.identifier.urihttp://hdl.handle.net/10179/17177
dc.publisherMassey Universityen_US
dc.rightsThe Authoren_US
dc.subjectAnti-infective agentsen
dc.subjectAntibiotics in food preservationen
dc.subjectClostridiumen
dc.subject.anzsrc310701 Bacteriologyen
dc.subject.anzsrc300607 Food technologyen
dc.titleAntimicrobial potential of Clostridium and closely related species derived from farm environmental samples : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Manawatū, New Zealanden_US
dc.typeThesisen_US
massey.contributor.authorWeligala Pahalagedara, Amila Srilal Nawarathnaen_US
thesis.degree.disciplineFood Technologyen_US
thesis.degree.grantorMassey Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophy (PhD)en_US
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