The Isolation and Preliminary Study of Some Physiological Characteristics of the Predominating Flora from the Rumen of Cattle and Sheep

作者：L. S. Gall, C. N. Stark, John K. Loosli · 发表于：Journal of Dairy Science · 年份：1947 · DOI：10.3168/jds.s0022-0302(47)92414-4 · 被引用次数：40 · 研究领域：Ruminant Nutrition and Digestive Physiology

Summary 1.New techniques for studying the microbiology of the rumen are described. These include a direct slide count technique, a cultural procedure for isolating the predominating flora, a method for obtaining a sample under anaerobic conditions, and methods for the determination of urea utilization and cellulose digestion by the predominating bacteria. 2.The direct slide count technique made use of nigrosine, a negative stain, which reduced to a minimum inaccuracies caused by artifacts. 3.When good cultural conditions prevailed and a fistulated animal was used, slide and cultural counts agreed closely. Material obtained by stomach tube gave consistently lower bacterial counts than samples taken directly from a rumen fistula. To isolate the predominating flora, the most important feature of the cultural technique was the maintenance of anaerobic conditions from the time of sampling until growth was obtained. A rich organic medium with a pH of 6.0 was used and cultures were incubated at 38° C. 4.It was shown by these methods that bacteria are present in the rumen contents of both sheep and cattle in numbers of about 100 billion per gram of fresh material. 5.Bacteria isolated from the highest dilutions of rumen contents from both sheep and cattle were tested for their ability to utilize urea and break down cellulose, and many of these cultures proved capable of performing these functions in vitro. 6.A few of the bacteria isolated from the highest dilutions of rumen contents w...