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Microbial and algal alginate gelation characterized by magnetic resonance

Author:
Fabich, Hilary T., Vogt, Sarah J., Sherick, Matthew L., Seymour, Joseph D., Brown, Jennifer R., Franklin, Michael J., Codd, Sarah L.
Source:
Journal of biotechnology 2012 v.161 no.3 pp. 320-327
ISSN:
0168-1656
Subject:
Pseudomonas aeruginosa, alginate gels, alginates, biopolymers, biotechnology, calcium, chemical structure, gelation, image analysis, ions, mutants
Abstract:
Advanced magnetic resonance (MR) relaxation and diffusion correlation measurements and imaging provide a means to non-invasively monitor gelation for biotechnology applications. In this study, MR is used to characterize physical gelation of three alginates with distinct chemical structures; an algal alginate, which is not O-acetylated but contains poly guluronate (G) blocks, bacterial alginate from Pseudomonas aeruginosa, which does not have poly-G blocks, but is O-acetylated at the C2 and/or C3 of the mannuronate residues, and alginate from a P. aeruginosa mutant that lacks O-acetyl groups. The MR data indicate that diffusion-reaction front gelation with Ca²⁺ ions generates gels of different bulk homogeneities dependent on the alginate structure. Shorter spin–spin T₂ magnetic relaxation times in the alginate gels that lack O-acetyl groups indicate stronger molecular interaction between the water and biopolymer. The data characterize gel differences over a hierarchy of scales from molecular to system size.
Agid:
111040