Bacteria with the ability to break down certain types of plastic are placed with a colony of E. coli bacteria that lack this ability. Plasmid transfer occurs between the two colonies of bacteria and some of the E. coli gain the ability to break down plastic as well. What inference can be drawn about the nature of plasmids from this observation?
Answers
Answer:
Explanation:
To date plasmid-mediated horizontal gene transfer is recognized as a major driving force for bacterial adaptation and diversification. Different environmental settings have their distinct bacterial community composition, which determines - possibly with the exception of broad-host range plasmids - the type of dominant plasmids that can be found. It is assumed that only a fraction of a population carries plasmids, which will ensure a rapid adaptation of the population to changing environmental conditions [1]. Without any doubt plasmid-mediated spread of antibiotic resistance genes among bacteria of different taxa is one of the most impressive examples of bacterial plasticity in response to various selective pressures [2,3]. While the molecular biology of plasmid-encoded replication, maintenance and transfer processes of some plasmids has been studied for decades, little attention has been paid to their dissemination in the environment, their ecology and the factors that drive their spread and diversification. In an overwhelming number of studies, the investigated plasmid-carrying strains originate from clinical specimen or diseased plant material, mostly human or plant pathogens. The reason for the lack of studies regarding the ecology of plasmids in natural settings was mainly the lack of tools to detect and quantify plasmids and to successfully culture their hosts.