Selenomonas ruminantium
Selenomonas ruminantium is a species of "Selenomonas" bacteria which are closely associated with ruminants, aiding in digestion of their food. It is predominantly observed in the rumen of these animals, and is strictly anaerobic. Shape and classification. The bacterium has a rod shaped structure. Gram. 16S rRNA test. The bacteria "Selenomonas ruminantium" was considered a gram positive bacteria by the 16S rRNA.It was believed to be correct until the flagellar basal test was performed. Flagellar basal test. The observation of flagella under electron microscope revealed the presence of four rings, a typical sign of gram negative species. Observation  of the flagellar basal structure confirms that "S. ruminantium" has an outer membrane, a characteristic of Gram-negative bacteria . Gram-positive outer membranes or mycomembranes were recently reported for the Gram-positive general "Corynebacterium" and "Mycobacterium", but none of them have flagella. Flagellae. Flagellae are a bunch of thread like structures, that actually helps in the movement of the organism. Tuft flagellae. The tuft of flagellae is seen arising from the concave of basal body of "S.ruminantium." The movement is achieved by self rotation about the axis of the body by the rotational force exerted by the tuft at the  centre. If the polar region to midpoint distance is considered as 50% the tuft is located at the midpoint represented as 50% of the organism. Lateral flagellae. The bacteria also exhibits polar or lateral flagellar structures depending upon the medium in which they are developed. Polymorphism in flagellar structures. Their flagellae exhibits polymorphic properties depending upon the environment of the bacteria. Generally the flagellae protruding from all points are clustered around the midpoint. Flagellin is glycosylated. pH effect on the structure of flagellae. The bacterial flagellae's existence depends upon the pH.The rumen pH is about 5.5 to 7. Mobility . Glucose effect. The medium of development determines the motility of the bacteria. For "Selenomonas ruminantium", glucose suppresses the flagellation. Swim. The microbe swims by self rotation about the axis of the body unlike its nearest appropriate comparison "R.sphaeroides", which the microbe rotates in a direction perpendicular to the axis of the body. The average number of flagellae per 20 cells is 6.The microbe swims with a speed of 16ɥm/s. Hooks. The shape and size of the hooks on the flagellae differ by the physiological conditions present, but the general structure is S shaped.