Myxococcus xanthus is a Gram-negative rod-shaped bacterium which we can find on soils. When starvation conditions are present, goes into a developing time what after a few hours it will create this structure called fruiting body, which can contain around 100,000 individual cells.
Inside of this structure, rod-shaped cells can differ into spherical, with thick walls spores. During this process a series of Biochemical reactions and changes occur, such as synthesis of new proteins and changes in the cell wall. Studies have shown that they are several different intercellular signals are required to get through this developing stage. These signals have been identified as A signal, B signal and C signal. The importance of these signals is indispensable for developing a fruiting body. For the identification of these signals a Tn5-lac transposon mutagenesis was used.
During the formation of fruiting bodies, these cells give an appearance of ridges which create a feeling of movement in traveling waves called ripples. Both fruiting body development and rippling are observed in various myxobacterial species. Ripples wax and wane over a 5 hour period during the developmental process, but are not required to form fruiting bodies. Further studies on ripples should let us know how the myxobacteria coordinate their movement.
Coordinated cell motility, also occurs during vegetative growth. Their behavior has been classified as a "wolf-pack" behavior which facilitates the predatory way these bacteria feed, utilizing the extra amount of digestive enzymes that are created by this organism. M. xanthus movement it is not yet well understood, this movement is called gliding. This movement is controlled by 2 genetic systems: the adventurous (A) and social (S) motility. S-motility comes activated when other cells are close to each other, and A-motility it is more of an independent movement. If mutations on either of these 2 systems occur, they do not interfere with each other, but it does interfere with both ways of swarming.
This is a photograph of multicellular fruiting bodies.Myxococcus xanthus fruiting body development is induced by amino acid limitation. The decision to grow or develop is established by the RelA-dependent stringent response and A-signaling
This interesting Microbe was first isolated by Roland Thaxter in 1892; he declared then a weird and unusual type of bacteria. He cultured and studied different types of Myxobacterias in different studies.
These bacteria are also called the “social” bacteria based since their entire life cycle is based upon cell-cell interaction. They also have a huge genome (9,454-9,870 kbp), as well as their mysterious msDNA.
There are a lot of mysteries left to be discovering with these bacteria and researches don’t understand what trigger their interest to study this specific type of “social” bacteria.*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.
Return to Missouri S&T Microbiology HomePage Go to DJW's HomePage
This Document is maintained by djwesten@ mst.edu
