IntroductionThe diet of ruminants is rich in fiber (made up of polymers, for example cellulose) and low in protein. Almost all animals and mammals lack the enzymes necessary for cellulose metabolism. Only microorganisms have such enzymes that facilitate the fermentation of cellulose and other polysaccharides consumed by ruminants. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”?Get the original essayMicroorganisms have a symbiotic relationship with the host.Rumen HabitatThe rumen, a special digestive organ that houses billions of microorganisms, including bacteria, protozoa and fungi that exist together. Such a habitat presents certain conditions that favor the residence of these microbes. Anatomy of the rumen The characteristics of the rumen which maintain the microorganisms are: A spacious rumen Anaerobic fermenter Warm and constant temperature (39 ℃) Narrow pH range (5.5 to 7. 0 depends on diet and saliva production)Digestive system of ruminants consists of 4 compartments:RumenReticulumOmasumAbomasumDigestive mechanism - food first passes from the esophagus to the reticulum and rumen, then to the omasum and finally to the acid abomasum. Among these compartments, the rumen is considered the main fermentation reservoir which contains the microorganisms Rumen MicrobiotaMicroorganisms are in a symbiotic relationship in the anoxic rumen. The microbiota is composed of bacteria, protozoa and fungi, at concentrations of 1010, 106 and 104 cells/ml, respectively. . It is obvious that the bacterial population is the most abundant and that any physicochemical change is vulnerable. Ruminal bacteria The rumen contains a diverse bacterial flora. Ruminants being herbivorous, cellulose is one of the main components of their diet, the need to break it down is therefore essential. Thus, the presence of cellulose degrading bacteria such as Fibrobacter succinogenes, Butyrivibrio fibrisolvens help to break the β 1,4 glycosidic bonds of cellulose, thereby providing nutrition to the host. The ruminant intestine also contains amylolytic bacteria such as S. bovis that help break down starch. component of the host's diet. In addition, the rumen also contains important degrading bacteria, such as lactate-degrading bacteria, pectin-degrading bacteria, etc. Total rumen bacteria help produce volatile fatty acids which are fermentation products that help maintain the biochemical pathways present in its gut. These abundant bacteria are digested in the acidic abomasum, providing vital proteins and vitamins to the rumen. host. The abundance of ruminant bacteria depends on the diet followed by the ruminant. Ingested feed proteins and polysaccharides are degraded by proteolytic bacteria - Bacteroides amylophilus, Bacteroides rutminicola and Butyrivibrio fibrisolvens Lipids are converted to saturated fatty acids in the rumen by lipolytic bacteria. Examples - Megasphaera elsdenii, B. fibrisolvens. In addition to ruminal bacteria, there is the presence of archaea or methanogens. Carbon dioxide and hydrogen formed during fermentation are converted to methane by methanogens such as mobile methanomicrobium, methanobrevibacter ruminantium. These microorganisms can also degrade substrates containing methyl (CH3-) or acetyl (CH3OO-) groups, such as methanol and acetate. In addition to prokaryotes there are protozoa and fungi (table 2). Both play a role in the metabolism of ingested foods..