I'm assuming bacteria, but will take any suggestions. Organism must survive primarily on the acetate (plus trace elements), but I can give/take electrons, if necessary. Not interested in strict anaerobes. I've tried Shewanella oneidensis, but have not succeeded in getting it to eat any acetate (just lactate). Feel free to give journal refs. Self-promotion won't be frowned upon if it's helpful. :-) Opportunity for joint pub, if successful.
You could try Paracoccus denitrificans.
Here is a study where acetate is used as the growth-limiting substrate: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.320.1692&rep=rep1&type=pdf
Here's the details of its version of acetate kinase: http://www.uniprot.org/uniprot/A1B9S8
I'd be happy to collaborate with you further on this.