You've Just Isolated a New Bacterium in Pure Culture, and You

Multiple Choice

You've just isolated a new bacterium in pure culture, and you culture it on a general purpose medium where its cells have a rod-shape (bacillus) morphology.In addition to culturing it on solid media, you inoculate a slide to grow it as a biofilm.When you use confocal microscopy to image the biofilm, you observe that there are several cellular morphologies, ranging from coccus to coccobacillus to long bacillus.The best explanation for this observation is that

A) the confocal microscope is out of adjustment.
B) the biofilm is no longer a pure culture of the microbe.
C) the biofilm culture was not incubated under the appropriate conditions.
D) the microenvironments within a biofilm promote structural variation.