{"id":45,"date":"2021-11-30T03:56:18","date_gmt":"2021-11-30T03:56:18","guid":{"rendered":"https:\/\/sites.massey.ac.nz\/sflint\/?page_id=45"},"modified":"2024-10-04T01:00:08","modified_gmt":"2024-10-04T01:00:08","slug":"current-projects","status":"publish","type":"page","link":"https:\/\/sites.massey.ac.nz\/sflint\/current-projects\/","title":{"rendered":"Current Projects"},"content":{"rendered":"\n
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Bolin Li started his PhD in October 2024. He is studying multi-species biofilms from dairy farm systems. His project is in conjunction with the Fonterra Research and Development Centre. Bolin did his Master degree at the University of Wageningen before joining us here at Massey University. <\/figcaption><\/figure>\n\n\n\n

Bolin’s supervisors are<\/p>\n\n\n\n

Denise Lindsay<\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n\n\n\n\n

Saili Chalke<\/strong><\/h2>\n\n\n\n
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Saili is studying the effect of ions on the biofilm formation of Listeria monocytogenes. <\/em>This project has a focus on the seafood industry but her results could equally apply to fresh produce. Her study is aimed at providing some insight into the environmental conditions that influence biofilm formation of these bacteria through examining biochemical changes, phenotypic changes and gene expression resulting from different combinations of ions. This information will aim to enable some control of the environment to reduce the risk from L. monocytogenes<\/em> biofilm formation.<\/p>\n\n\n\n

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Supervisors<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n

Graham Fletcher<\/p>\n\n\n\n

Sinisa Vidovic<\/p>\n\n\n\n

<\/p>\n\n\n\n\n\n\n\n

Farawahida Abdul Halim<\/strong><\/h2>\n\n\n\n
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<\/p>\n\n\n\n

Farah is studying mycotoxins in a fermented rice  – Red Rice. Her project involves looking at the microbial ecology of the rice and the factors contributing to mycotoxin production during the fermentation. Altering the fermentation method to prevent mycotoxin production or treating rice with novel technologies to degrade the toxins once formed are two approaches she will investigate to improve the safety of this product.<\/p>\n\n\n\n

Supervisors:<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n

Mussalbakri Abdul Manan<\/p>\n\n\n\n

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Srinithi Muthurman<\/strong><\/h2>\n\n\n\n

We know that biofilms are comprised of an extracellular matrix containing mixtures of polysaccharides, lipids, extracellular DNA and proteins. We hypothesise that there is much more to the composition of the matrix.  <\/strong>To test this hypothesis will require a new approach to the study of EPS that will involve bio-chemical analysis and modelling. Our understanding of the composition and complexity of the extracellular matrix in biofilms continues to evolve. For example, two distinct functional roles for the Bacillus<\/em> amphipathic protein that contributes to the hydrophobicity of B. subtilis <\/em>are now known. This protein exists as a monomer or dimer depending on the redox potential in the biofilm and this has implications in the architecture of the biofilm. Another example of a recent development in knowledge of EPS is confirmation that the release of extracellular DNA into the matrix is an active process associated with DNABII proteins, independent of cell lysis and occurs in a specific location in the bacterial outer membrane.<\/p>\n\n\n\n

In a study of biofilms in dairy wastewater treatment systems a mixed population of bacteria was associated with a tissue-like, highly structured extracellular mass containing poly-\u03b2 hydroxyl alkanoate (PHA), a polyester produced by microorganisms used as an energy source. This exogenous rather than endogenous presence of PHA was unexpected although another report appeared recently involving PHA in biofilm formation. Questions that we would like to answer are: how do these microbial compounds become involved in the extracellular matrix?, what role do they have in the survival of the cells comprising the biofilm?, how are they involved in generating the EPS structure?, what other molecules in the extracellular matrix are involved?, how do these substances vary in different conditions?, how do they contribute to the re-colonisation of surfaces with microorganisms (important in the food industry) and finally can we model the production of EPS to develop strategies to control EPS production?<\/p>\n\n\n\n

To answer these questions, metagenomics within EPS samples from different environments will scope out potential candidate microflora for EPS production. The chemical composition of the EPS taken will be determined with GC-MS analysis and the structure will be determined through NMR7<\/sup>. We will model the conditions leading to EPS production using a one dimensional (N1) model as such models can input a number of factors such as thickness and concentration of different components. Predominant microflora will be isolated and RNA-seq analysis will be used to investigate gene expression under conditions identified by the model as being critical for EPS production.<\/p>\n\n\n\n

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Supervisors<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n\n\n\n\n

Ili Syuhada Mohd Daud<\/strong><\/h2>\n\n\n\n
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Ili is exploring the antimicrobial properties of lemongrass. Her project is studying the mechanism of antimicrobial activity and characterising that activity in terms of the spectrum of activity and tolerance to different extrinsic factors that are important in the application as a preservative in the food industry. She will be looking at the factors that may enhance the antimicrobial activity, focusing on stress factors that can be applied to the plant.<\/p>\n\n\n\n

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Supervisors<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n

Nor Khaizura AB Rashid<\/p>\n\n\n\n\n\n\n\n

Krisha Pant<\/h2>\n\n\n\n
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Krisha is investigating the growth and characteristics of mixed species biofilms. This is a new direction for our group in biofilm studies as most of our work has focused on single species biofilms. Krisha is looking at the interactions between Pseudomonas, Staphylococcus <\/em>and Listeria <\/em>in biofilms. Her studies are providing us with a new understanding of how these species influence each other in a biofilm that will be relevant to the food industry, influencing the quality and safety of food. <\/p>\n\n\n\n

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Pseudomonas <\/em>biofilm in stainless steel<\/figcaption><\/figure>\n\n\n\n

Supervisors<\/strong>:<\/p>\n\n\n\n

Steve Flint <\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n

<\/p>\n\n\n\n\n\n\n\n

Yining (Gloria) He<\/h2>\n\n\n\n
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Yining is the second PhD student to work on cold plasma. Her project is exploring the effect of cold plasma and plasma treated water in the inactivation of biofilms. Listeria monocytogenes<\/em> is the microorganism of interest for her project. She is exploring various parameters in the production and storage of plasma treated water in the treatment of biofilms and examining the mechanism of activity in disruption of biofilms. <\/p>\n\n\n\n

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The di-electric barrier cold plasma system that Yining is using for her studies<\/strong><\/figcaption><\/figure>\n\n\n\n

Supervisors<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n

<\/p>\n\n\n\n\n\n\n\n

Thi-Van (Van) Nguyen<\/h2>\n\n\n\n
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Van is looking at the potential of bacteriocins for use as a natural control measure for biofilms in the food industry. Van has acquired several bacteriocin producing bacteria that produce different bacteriocins. Biofilm inhibition and the destruction of pre-formed biofilm are the aim of her studies. The interaction of bacteriocins with biofilm will be explored through the effect on biofilm gene expression and quorum sensing. Single bacteriocins will be compared with combinations of bacteriocins to enhance biofilm control. <\/p>\n\n\n\n

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An outline of Van’s plan for her project<\/figcaption><\/figure>\n\n\n\n

Supervisors<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n

<\/p>\n\n\n\n\n\n\n\n

Hansani Nilupama Kumari<\/h2>\n\n\n\n
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Hansani is studying Vibrio parahaemolyticus<\/em> biofilms, focusing on conditions leading to biofilm formation that may influence food safety in the seafood industry. Critical factors are temperature and an air liquid interface. Growth of biofilm on oyster shell surfaces and surfaces in seafood processing plant are potential sources of contamination that may lead to food poisoning. Climate change is believed to be having an influence on the numbers of illness being reported and Hansani’s work supports this assumption as temperature has an important effect on biofilm formation. The challenge is to replicate conditions in seawater in the laboratory, particularly around replicating the optimum air exposure for maximum biofilm formation. <\/p>\n\n\n\n

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Examples of the biofilm growth on stainless steel coupons at an air\/liquid interface<\/figcaption><\/figure>\n\n\n\n

Supervisors<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n\n\n\n\n

Dilushi Sureka Ruwan Kumari<\/h2>\n\n\n\n
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Dilushi is exploring the effect of two antimicrobials, lysozyme and nisin, on the control of biofilms of Listeria monocytogenes.<\/em> Her initial studies are exploring the effect of nutrient concentration on the activity of these two antimicrobials which is likely to have an important contribution to the efficacy in a biofilm environment. Preconditioning to different nutrient concentrations appears to have a major effect on antimicrobial activity. <\/p>\n\n\n\n

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Plans for initial work examining the effect of nutrient concentration on antimicrobial activity.<\/figcaption><\/figure>\n\n\n\n

Supervisors<\/strong><\/p>\n\n\n\n

Steve Flint<\/p>\n\n\n\n

Jon Palmer<\/p>\n\n\n\n

Eric Alterman<\/p>\n","protected":false},"excerpt":{"rendered":"

Bolin’s supervisors are Denise Lindsay Steve Flint Jon Palmer<\/p>\n","protected":false},"author":184,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-45","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/pages\/45","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/users\/184"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/comments?post=45"}],"version-history":[{"count":20,"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/pages\/45\/revisions"}],"predecessor-version":[{"id":359,"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/pages\/45\/revisions\/359"}],"wp:attachment":[{"href":"https:\/\/sites.massey.ac.nz\/sflint\/wp-json\/wp\/v2\/media?parent=45"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}