M. mycoides certainly does not survive on that. Mycoplasmas need cholesterol and lipids because they lack the HMGCoA reductase pathway and FAS, so all the media you grow them on are enriched for that (started as FBS, but we found horse serum worked great and was cheaper). In general, I think you need a few more things than just that for most basic life (nitrogen, phosphorus, metals)... Is using glucose cheating? Because you could use light for energy and CO2 for carbon, but that adds a ton ton ton of genes...

So this becomes a nitpicky definitional conundrum.

There are no bacteria with smaller genomes today, that was the point of making this one. I was not talking about the global environment either, but the number of options for what substances and concentrations may need to be present in the environment around a cell is certainly very large - making trial and error difficult.