PGA was anticipated to display high antifreeze activities because
of its high acidic amino acid composition. Investigations on
antifreeze activities of PGA from B. licheniformis by DSC showed
that PGA with molecular weight below 20,000 had antifreeze activity
higher than that of glucose. The antifreeze activities of PGA
were slightly affected by the optical isomerism and decreased in
the order Na salt = K saltCa saltacidic form. Shih et al.
(2003) demonstrated the antifreeze activity of PGA to increase
with a decrease in its molecular weight, but was indifferent to its
D/L-glutamate composition