Bac-Shield for Chemists


Bac-Shield’s active ingredient is Chitosan. Chitin and Chitosan are naturally occurring β-1,4-linked linear polysaccharides. Chitin is essentially a homopolymer of 2-acetamido-2-deoxy-β-D-glucopyranose. Chitosan is the N-deacetylated derivative of Chitin, most of whose glucopyranose residues are 2-2-deoxy-β-D-glucopyranose.


Chitin is most commonly derived from crustacean shells, particularly from crabs and shrimp. Commercially, Chitosan is prepared through the deacetylation of Chitin. Chitin is extracted by acid treatment to dissolve the calcium carbonate followed by alkaline extraction to dissolve the proteins and by a depigmentation step to obtain a colorless product mainly by removing the astaxantine. Two production chemicals, hydrochloric acid and sodium hydroxide, are neutralized to create “salt water”.

Bac-Shield Manufacturing Process

How Chitosan Works

Two main mechanisms have been suggested as the cause of the inhibition of microbial cells by Chitosan. The first is its interaction with anionic groups on the cell surface that, due to its polycationic nature, causes the formation of an impermeable layer around the cell, preventing the transport of essential solutes.  The second involves the inhibition of the RNA and protein synthesis by permeation into the cell nucleus.* Chitosan has been an object of study for decades and there are many publicly available reports describing the activity of chitosan, for example:

Laboratory Tests of Bac-Shield’s Effectiveness

* Helander I, Nurmiaho-Lassila E, Ahvenainen R, Rhoades J, Roller S.(2001) “Chitosan disrupts the barrier properties of the outer membrane of Gram-negative bacteria”, International Journal of Food Microbiology 71 pp.235-44.  Liu X, Yun L, Dong Z, Zhi L, Kang D. (2001), “Antibacterial action of chitosan and carboxymethylated chitosan”, Journal of Applied Polymer Science 79(7) pp. 1324-35.