Missed first base and then tagged

[GrizzlyUmp14]

Varsity summer baseball - not the best game I've ever seen. There is a ground ball to the first baseman, which he bobbles. He eventually gets the ball and attempts to tag the runner, but misses him. The runner does not touch first base, but instead runs over it. The fielder then tags the runner. Is he out or not? Some other umpires said this would have to be an appeal play for missing a bag because once the runner "passes" a base, he has acquired that base. If that is the case, does tagging a runner count as an appeal or does the fielder have to verbally appeal the missed base?