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Volume 8
Journal of Biotechnology & Biomaterials
ISSN: 2155-952X
Biotech Congress 2018 & Enzymology 2018
March 05-07, 2018
JOINT EVENT
20
th
Global Congress on
Biotechnology
3
rd
International Conference on
Enzymology and Molecular Biology
&
March 05-07, 2018 London, UK
Characterization of antifreeze activity in apoplastic extract of
Deschampsia antarctica
Farías J G, Short S
and
Bravo L A
Universidad de La Frontera, Chile
D
eschampsia antarctica
Desv. is a vascular plant species that colonized maritime Antarctica exhibiting extreme freezing
tolerance (-27°C). This has been associated with apoplastic antifreeze activity. Antifreeze proteins (AFPs) have the ability
to bind to the growing surface of ice crystals inhibiting their growth; however, this activity has been poorly characterized in
this species. Therefore, the aim of this work is to characterize the antifreeze activity of apoplastic extracts from
D. antarctica
.
To understand how this plant can tolerate freezing temperatures year-around, and in order to evaluate the potential antifreeze
activity of apoplastic proteins from
D. antarctica
as future applications, experiments have been developed in cold-acclimated
and non-aclimated plants. To identify the best apoplastic proteins accumulation after plant cold-acclimation, apoplastic
extracts were quantified every four days for 21 days of low temperature exposure. Antifreeze activity was determined by ice
recrystallization inhibition (IRI), thermal hysteresis activity (TH) and ice crystal growth in dilution series of apoplastic extracts.
The results indicate that the minimum IRI activity was evident in extracts with a concentration equal to 0.005 μg/μl at cold-
acclimated condition, while in non-aclimated plants the IRI activity was lost at 0.05 μg/μl. At concentration equal to 2.5 μg/μl,
ice crystals showed a bipyramid shape and a TH equal to 0.4°C. In conclusion, we observed that cold-acclimation increased
apoplastic antifreeze activity, obtaining higher IRI but low TH in these apoplastic extracts. This high IRI is remarkable and
further studies are needed to characterize the apoplastic extract to associate this activity to apoplastic antifreeze proteins which
could be of interest for later studies as a cryoprotectant.
Biography
Farías J G is the Associate Professor and Director of the Chemical Engineering Department, Universidad de La Frontera. His research interest is in Pharmaceutical
Biotechnology, focusing on Molecular Therapeutics and Drugs Production. He has published 51 articles in reputed journals.
jorge.farias@ufrontera.clFarías J G et al., J Biotechnol Biomater 2018, Volume 8
DOI: 10.4172/2155-952X-C2-092