I'm very happy that you learnt something! I also didn't know about the bitwise operator. My advice stands though; if you are working with large datasets of genome sequences, to me it's quite clear that BioPerl is the right tool for the job.

If, however, you are just doing exercises to practice your Perl skills, then it's fine to roll your own solution, but it seemed to me that neversaint was trying to do some actual work.