Isolation, Enumeration, and Characteristics of Proteolytic Ruminal Bacteria

Fulghum, Robert S. (Virginia Polytechnic Institute, Blacksburg) and W. E. C. Moore. Isolation, enumeration, and characteristics of proteolytic ruminal bacteria. J. Bacteriol. 85:808-815. 1963.-Colony counts of proteolytic ruminal bacteria in the order of 10(9) organisms per g of whole rumen contents, and total colony counts in the order of 2 to 3 x 10(9) organisms per g, were obtained from rumen contents of cattle fed a maintenance ration of hay and grain. The proteolytic counts averaged 38% of the total counts. An anaerobic, differential medium characterizing proteolytic colonies by clear zones in an opaque skim-milk suspension was utilized. Proteolytic isolates were assigned to the following taxa: Butyrivibrio sp., Succinivibrio sp., Selenomonas ruminantium var. lactilytica, Borrelia sp., Bacteroides sp., and selenomonadlike organisms similar to the B-385 group of Bryant.