Characterising Fish Collagen for Expression in Bacterial Systems
Publication Date
July 31, 2025
Creator
Abstract
Isinglass, a collagen-based fining agent commonly used in the brewing industry for centuries, is traditionally produced from the swim bladder of tropical and sub-tropical fishes. However, the production of isinglass raises sustainability concerns, such as overfishing and environmental impact.
Arius maculatus, the species widely used in commercial isinglass production, there is limited data available on the specific protein characteristics of the collagen derived from this source. This study aimed to optimise the extraction and preliminary characterisation of collagen from isinglass from Arius maculatus swim bladders in a laboratory setting, addressing the gap in existing knowledge.
The collagen extraction process was refined using acid extraction techniques. The resultants were analysed through SDS-PAGE, revealing the presence of two α-chains and a β-chain with molecular weights slightly over 115kDa and 190kDa, respectively. The study provided essential preliminary data on the molecular structure of this collagen for the future work on the full confirmation of the protein structure. The functionality of these crude extracts as a fining agent was compared against commercial products. The findings reveal that laboratory-extracted protein crude shared structural characteristics with collagen type I and potential in maintaining functionality in finings.
The study also pursued the goal of expressing this collagen in a bacterial host; however, achieving suitable DNA templates for PCR was challenging. Repeated failures with commercial DNA extraction kits led to the development of an optimized protocol using conventional methods, yielding high-molecular-weight genomic DNA (>10 kb) for potential future applications. While time constraints prevented the completion of gene expression efforts, this research successfully refined both collagen and DNA extraction techniques, providing a critical foundation for future work on sustainable isinglass production and related collagen-based applications.
Item Type
ethesis
Thesis Type
MRes
Supervisors
Subjects (LC)
Associated Schools / Departments
School of Biosciences (UK)
eprints ID
80151
UoN Repository URI
Except where otherwise noted, this item's license is described as
File(s)![Thumbnail Image]()
Name
Shi, Xiaoqin, 20398717, Re-submission .pdf
Type
Full-text
Description
Examined
Size
1.41 MB
Format
Adobe PDF
Checksum (MD5)
070f8632fbf6d5b5dab9f8a43bd2a08a