The characteristics of alginate salts

Also known as alginate gel, alginate or alginate. It is a salt of alginate. A long-chain polymer composed of (1-4) - β - crosslinked D-mannuronic acid and (1-4) - α - crosslinked glucuronic acid, with a relative molecular weight of approximately 10 ^ 6. It mainly exists in the cell wall and intercellular mucin of brown algae, as well as in some bacteria such as pseudomonas and nitrogen fixing bacteria that produce sticky capsules. Alginate from algae is insoluble in water, but its sodium salt is easily soluble in water. When alginate solution meets Ca2+, it forms gel. A molecule of alginate often exists in three regions, namely the "M region" (rich in mannuronic acid region), the "G region" (rich in glucuronic acid region), and the "MG region" (both types of uronic acid are present). Ca2+and other bivalent cations are easy to combine with the G region, so calcium alginate gel is considered to be a three-dimensional network molecule in which Ca crosslinks the G region of long-chain molecules. The composition of alginate varies among different organisms. For example, in some types of alginate, the M region accounts for 93%, the G region only accounts for 3% (such as Ascophyllum modosum), while in others, the M region only accounts for 62% (such as Laminia digitata). Different M/G values can significantly affect their physicochemical properties. Azotobacter vinelandii can also produce alginate, as it can be produced in artificial environments and is not limited by geographical and seasonal factors, making it a potential new source of alginate.