Peptidoglycan is like to a bacteria what cellulose is to a plant cell or collagen is to a human cell, a matrix of some tough stuff outside the plasma membrane.
On another board a guy was telling me that if a bacteria was the size of a car in a big swimming pool or something you would see it churning water and surrounded in a stinky cloud of various kinds of greasy crud it keeps belching out.
What I was wondering was more along the lines of the guidance system. The chemotaxis page didn't offer anything new. That video seems to show more than the emergent behavior of a cell with receptor sites all over it heading up some chemical gradient - if that was the case, then when it passes that other bacteria you would expect it to stick a pseudopod or something out that way. Instead, it actively ignores it and concentrates on its initial prey. Awesome.