What is growing in my petri dish of ecoli?

This is probably a silly question but I am new to biology and have done a lab where ecoli is in a liquid medium on a petri dish then we used different soaps to get different zones of inhibition. In our regular hand soap the ecoli began to grown in a quadrant then spread through the entire dish. What exactly is it that is growing? Our instructor said we do not have to know for our report but I am very curious. The growth was not in the distilled water, organic soap or the antibacterial hand soap. Kind of a cloudy fiber like growth. Any help would be great thanks! <><