The direct answer to your question is, no there is no formal certification to be a recording engineer. There are a number of schools that offer hands on training in recording techniques and there are even college degrees in recording technology, but this sort of formal training is not a requirement to get a job as an engineer.
Any recording is a collaborative effort between the musicians, the producer, the recording engineer, the mastering engineer and record company. The final sound of a recording is the collective product of all these peoples' efforts. A quality recording or mastering engineer shouldn't have an identifiable sound. Instead, just as with a top flight studio musician, there work should remain unobtrusive and all their decisions should be done in the context of someone else's musical vision.
Any recording is a collaborative effort between the musicians, the producer, the recording engineer, the mastering engineer and record company. The final sound of a recording is the collective product of all these peoples' efforts. A quality recording or mastering engineer shouldn't have an identifiable sound. Instead, just as with a top flight studio musician, there work should remain unobtrusive and all their decisions should be done in the context of someone else's musical vision.