Animal Minds; bacterial cooperation (Animals)

by David Turell , Thursday, December 10, 2015, 16:03 (3273 days ago) @ dhw

Groups of bacteria can share in different responsibilities and exclude the cheaters!-http://www.sciencedaily.com/releases/2015/12/151208133443.htm-"In natural microbial communities, different bacterial species often exchange nutrients by releasing amino acids and vitamins into their growth environment, thus feeding other bacterial cells. Even though the released nutrients are energetically costly to produce, bacteria benefit from nutrients their bacterial partners provide in return. Hence, this process is a cooperative exchange of metabolites. Scientists at the Max Planck Institute for Chemical Ecology and the Friedrich Schiller University in Jena have shown that bacteria, which do not actively contribute to metabolite production, can be excluded from the cooperative benefits. The research team demonstrated that cooperative cross-feeding interactions that grow on two-dimensional surfaces are protected from being exploited by opportunistic, non-cooperating bacteria. Under these conditions, non-cooperating bacteria are spatially excluded from the exchanged amino acids. This protective effect probably stabilizes cooperative cross-feeding interactions in the long-run. -***-"The fact that such a simple principle can effectively stabilize such a complex interaction suggests that similar phenomena may play important roles in natural bacterial communities," Christian Kost states. After all, bacteria occur predominantly in so-called biofilms -- these are surface-attached slime layers that consist of many bacterial species. Known examples include bacteria causing dental plaque or bacterial communities that are used in wastewater treatment plants. Moreover, biofilms are highly relevant for medical research: They do not only play important roles for many infectious diseases by protecting bacterial pathogens from antibiotics or the patients' immune responses, but are also highly problematic when colonizing and spreading on the surfaces of medical implants.-"This new study has elucidated that cooperating bacteria form cell clusters and in this way exclude non-cooperating bacteria from their community. "The importance of this mechanism is due to the fact that no complicated or newly-evolved condition, such as the recognition of potential cooperation partners, needs to be fulfilled to effectively stabilize this long-term partnership. Two cooperating bacterial strains and a two-dimensional surface are sufficient for this protective effect to occur," explains Kost."-Comment: This study shows a mechanism but not how it works through biochemical signals. It raises the same issue, intelligence vs. automatism through intelligently placed information instructions.