Question

Why is it difficult to classify bacteria?

Answer 1

My view is that classification relies too much on questions that are binary/binomial. For example, is it gram positive or gram negative. The reality is that as with most biochemical pathways, bacterial responses to their environment are not binary/binomial. Moreover, bacteria mutate quite rapidly, either through natural or induced mutations in the bacterial DNA as well as gain /loss of plasmid DNA. The best example is E.coli. There are thousands of laboratory strains each with a particular set of mutations. Some of the strains contain so many additions and deletions of DNA, it would be very difficult to classify them the same as wild type E. coli.