Microbial consortia are described as assemblages of different species of microbes in physical as well as biochemical contact with one another. This type of relationship between organisms is also known as microbe-microbe commensalism or mutualism. These types of relationships are becoming increasingly recognized as the “real world” of microbiology as opposed to single bacterial colony representations typically used in microbiological studies. It is thought that results of such experiments are often misinterpreted due to the previous belief of such entities existing as individuals instead of a complex network of multiple entities such as was reported in this previous study.
Using the theory of microbial consortia, researchers from Rice University have created a type of “living circuit” from multiple species of bacteria that trigger the bacteria to symbiotically cooperate to change protein expression. The study, published recently in Science, describes how the researchers constructed two genetically distinct populations of E. coli to create a bacterial consortia that exhibits synchronized transcriptional fluctuations which can be “activated” by one species and “repressed” by the other.
Both species were cultured together in a microfluidic device of a synthetic dual-feedback oscillator that typically functions with a single strain of bacteria. Time-lapse fluorescence microscopy was used to observe the two strains as they grew together inside of the chamber. When cultured together, synchronous, in-phase oscillations appeared in fluorescent reporters of the strains. Oscillations did not occur when either of the E. coli strains were cultured inside of the device individually.
The results of their study demonstrate that the engineering of population phenotypes in microbial consortia is possible. However; the population ratio within a consortia can fluctuate so special attention should be paid to the selection of bacterial isolates to engineer such synthetic circuits. This new study provides insight into the use of microbial consortia as a platform for testing the relationship between microbial populations and gene regulation. Such applications have the potential to be used in drug development where microbial “circuits” can turn signaling molecules on or off through specific controlled biologically processes in the body, such as diet.
I am a postdoctoral researcher with interests in pre-harvest microbial food safety, nonthermal food processing technologies, zoonotic pathogens, and plant-microbe interactions. My current research projects involve the optimization of novel food processing technologies to reduce the number of foodborne pathogens on fresh produce. I am a food geek!