Science Buddies: "Ask an Expert"

Hello,

I am conducting an experiment that requires me to have a liquid form of chitosan so I can saturate a paper disk with it and place the disk on agar. I need a detailed, but simple-to-read protocol explaining step-by-step how to extract chitosan from crab shells. I have found some procedures online but those are all general overviews. They do not have the steps listed in an organized manner. If someone is able to find one for me, that will be greatly appreciated.

Thank you.

Hi Kevin,

I haven't had any luck finding a step-by-step procedure for extracting chitosan, either. Have you considered purchasing some liquid chitosan online, since it is sold as a weight loss supplement?

Another idea would be to contact a lab at a local college to see whether someone could help you with the extraction.

I hope this helps you continue!

Heather

Hi Kevin,

I think Heather's suggestion to purchase the commercially available chitosan is a really good idea. Here is a paper that describes a step-by-step procedure for extracting chitosan. The procedure involves alternatively boiling the seafood shells in sodium hydroxide, soaking in hydrochloric acid, followed by boiling again in the sodium hydroxide. This is something you definitely do not want to do unless you had access to a laboratory with a hood and other safety equipment, such as a college laboratory that Heather suggested.

http://www.idosi.org/aejaes/jaes2(2)/1.pdf

This sounds like a really interesting project. What are you planning to do with the chitosan-saturated disks? Are you testing for antimicrobial activity?

Donna Hardy

Hi Kevin,

Heather and Donna have given you some excellent advice on contacting an institution to carry out the protocol.

I have found a two full length research papers that may guide you in conducting your experiment.

1. " Physicochemical and functional properties of crawfish chitosan as affected by dIfferent processing protocals"
: This is a paper that covers a thorough analysis on the biochemical properties of chitosan and its application in chitosan crawfish production.
http://etd.lsu.edu/docs/available/etd-1 ... thesis.pdf

2. Extraction of chitin and chitosan from shell and operculum of mangrove gastropod Nerita (Dostia) crepidularia Lamarck
: This paper discusses on the extraction of chitin from the shell and operculum of Nerita crepidularia and conversion of chitin into chitosan through deactylation
http://www.academicjournals.org/ijmms/P ... t%20al.pdf

Hope this helps and please ask if you have any more questions!

-Grace