Simple determination of microbial protein in rumen liquor

A method for microbial protein determination based on Lowry's assay was devised. Differential centrifugation was used to separate bacterial cells from rumen liquor. Proteins from cells were released by suspending in .25 N sodium hydroxide and heating in boiling water bath for 10 min. Protein was determined by the Folin phenol method. The method is simple, accurate, reproducible, sensitive, specific, brief, and can be performed with small amount of rumen liquor (5 ml). A large number of samples can be handled conveniently.