Are all ulvans equal? A comparative assessment of the chemical and gelling properties of ulvan from blade and filamentous Ulva

Joel T Kidgell; Susan M Carnachan; Marie Magnusson; Rebecca J Lawton; Ian M Sims; Simon F R Hinkley; Rocky de Nys; Christopher R K Glasson

doi:10.1016/j.carbpol.2021.118010

Are all ulvans equal? A comparative assessment of the chemical and gelling properties of ulvan from blade and filamentous Ulva

Carbohydr Polym. 2021 Jul 15:264:118010. doi: 10.1016/j.carbpol.2021.118010. Epub 2021 Apr 2.

Authors

Joel T Kidgell¹, Susan M Carnachan², Marie Magnusson³, Rebecca J Lawton⁴, Ian M Sims⁵, Simon F R Hinkley⁶, Rocky de Nys⁷, Christopher R K Glasson⁸

Affiliations

¹ MACRO - The Centre for Macroalgal Resources and Biotechnology, College of Science and Engineering, James Cook University, Townsville, 4811, Australia. Electronic address: joel.kidgell@my.jcu.edu.au.
² The Ferrier Research Institute, Victoria University of Wellington, Wellington, 6012, New Zealand. Electronic address: susie.carnachan@vuw.ac.nz.
³ Environmental Research Institute, School of Science, University of Waikato, Tauranga, 3110, New Zealand. Electronic address: marie.magnusson@waikato.ac.nz.
⁴ Environmental Research Institute, School of Science, University of Waikato, Tauranga, 3110, New Zealand. Electronic address: rebecca.lawton@waikato.ac.nz.
⁵ The Ferrier Research Institute, Victoria University of Wellington, Wellington, 6012, New Zealand. Electronic address: ian.sims@vuw.ac.nz.
⁶ The Ferrier Research Institute, Victoria University of Wellington, Wellington, 6012, New Zealand. Electronic address: simon.hinkley@vuw.ac.nz.
⁷ MACRO - The Centre for Macroalgal Resources and Biotechnology, College of Science and Engineering, James Cook University, Townsville, 4811, Australia. Electronic address: rocky.denys@jcu.edu.au.
⁸ Environmental Research Institute, School of Science, University of Waikato, Tauranga, 3110, New Zealand. Electronic address: christopher.glasson@waikato.ac.nz.

PMID: 33910714
DOI: 10.1016/j.carbpol.2021.118010

Abstract

Green seaweeds of the genus Ulva are rich in the bioactive sulfated polysaccharide ulvan. Herein we characterise ulvan from Ulva species collected from the Bay of Plenty, Aotearoa New Zealand. Using standardised procedures, we quantified, characterised, and compared ulvans from blade (U. australis, U. rigida, U. sp. B, and Ulva sp.) and filamentous (U. flexuosa, U. compressa, U. prolifera, and U. ralfsii) Ulva species. There were distinct differences in composition and structure of ulvans between morphologies. Ulvan isolated from blade species had higher yields (14.0-19.3 %) and iduronic acid content (IdoA = 7-18 mol%), and lower molecular weight (Mw = 190-254 kDa) and storage moduli (G' = 0.1-6.6 Pa) than filamentous species (yield = 7.2-14.6 %; IdoA = 4-7 mol%; Mw = 260-406 kDa; G' = 22.7-74.2 Pa). These results highlight the variability of the physicochemical properties of ulvan from different Ulva sources, and identifies a morphology-based division within the genus Ulva.

Keywords: Multivariate analysis; Rheology; Seaweed; Sulfated polysaccharide; Ulva; Ulvan.

MeSH terms

Cell Wall / chemistry
Iduronic Acid / analysis
Molecular Weight
Multivariate Analysis
New Zealand
Polysaccharides / chemistry*
Polysaccharides / isolation & purification
Rheology / methods
Seaweed / chemistry*
Spectroscopy, Fourier Transform Infrared / methods
Sulfates / chemistry
Ulva / chemistry*

Substances

Polysaccharides
Sulfates
ulvan
Iduronic Acid