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ARS Home » Research » Publications at this Location » Publication #115729
Title: A PRESSURE COOKER METHOD TO EXTRACT GLOMALIN FROM SOILS.

Author
item Wright, Sara
item Jawson, Linda

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Glomalin is a biological glue important in soil stability. It is insoluble in water, and solubilization requires high heat over a long period of time. Many soil testing laboratories cannot afford the cost of an autoclave - a heating vessel that can be used to attain the high heat necessary to solubilize glomalin. We tested pressure cookers to determine whether they would be a low-cost alternative to an autoclave. Equivalent amounts of glomalin were extracted in an autoclave and a large pressure cooker. This information will be valuable to laboratories worldwide that would like to test soils for glomalin.

Technical Abstract: Glomalin, a glycoprotein produced by arbuscular mycorrhizal fungi, is a major constituent of soil organic matter. Glomalin is insoluble and requires a chelator and high heat for solubilization. A small (4-L) and a large (14-L) pressure cooker were compared with an autoclave as heating vessels. Total glomalin concentration values from three soils were determined using 50 mM citrate, pH 8.0 as the chelator. Glomalin values were identical for extracts from the autoclave and the 14-L pressure cooker. A 4-L pressure cooker extracted slightly less glomalin than the other vessels and required twice the time. A large pressure cooker is a low-cost substitute for an autoclave and can be used to relate glomalin to soil management practices.