There is an electron transport chain in bacteria but they use it a bit differently (and if I remember correctly from microbio, it's located on the plasma membrane). Do not forget that bacteria can be aerobes too. Also if you think back to aerobic respiration in humans, we make 36 ATP from substrate and oxidative phosphorylation, where as bacteria make 38 ATP. All NADH in bacteria produce 3 ATP because there is no mitochondrial membrane to go through, whereas in humans, the two NADH from glycolysis only produce 2 ATP during oxidative phosphorylation (due to an intermediate carrier that must be used to bring the e- and energy pass the mitochondrian membrane and into the ETC). <--that was a mouth full, hopefully it made sense
Also if you look on page 348 of the 2011 Destroyer, the answer to #145 even says that they have their own ETC.