Rumen plasmids

The mammalian digestive tract is home to complex and important microbial communities. These microbial communities dwell in the digestive tract of their hosts and play a key role in the digestion of their hosts. One chief example for such a microbial community is the one hosted by the rumen, the anaerobic compartment in the ruminant digestive system, which is responsible for the ability of ruminants to convert indigestible plant polymers into digestible compounds. Thus, a better understanding of this bacterial community and its extraordinary abilities is of major interest. Understanding a bacterial community cannot stand without understanding lateral gene transfer and mobile genetic elements and their contribution to the structure and functionality of this community. Mobile genetic elements, as operators of lateral gene transfer, play a key role in shaping bacterial communities as they are distributers of genetic material with in the community. In the last few decades, it became evident that mobile genetic elements, especially plasmids are widespread in natural microbial communities in general and in the rumen microbial population specifically. Plasmids can be found in a wide range of rumen bacteria and a wide range of accessory functions are carried by these plasmids. Also, the plasmids in the rumen microbial community are tightly associated with their hosts as they harbor accessory functions which can confer advantages which are highly relevant to this ecological niche. This chapter discusses the rumen plasmids throughout their various aspects such as the presence and distribution of plasmids, the functions they carry as well as their possible role in biotechnology of the rumen microbial community.