Catalyzes the oxidation of ethanol and other primary alcohols to the corresponding aldehydes, except methanol, which is not a substrate (PubMed:7730276). Uses a specific inducible cytochrome c550, encoded by the adjacent gene in the locus, as electron acceptor (By similarity). Is a key enzyme of the carbon and energy metabolism during growth of P.putida on ethanol as the sole carbon and energy source (PubMed:18218017). Displays lower activity on secondary alcohols, aldehydes and diols. Is not active with sugar alcohols such as glycerol and D-sorbitol (PubMed:7730276). In vitro, reacts well with phenazine methosulfate (PMS) as an electron acceptor but not with NAD(P), potassium ferricyanide, or molecular oxygen (PubMed:7730276). a primary alcohol + 2 Fe(III)-[cytochrome c] = an aldehyde + 2 Fe(II)-[cytochrome c] + 2 H(+) ethanol + 2 Fe(III)-[cytochrome c] = acetaldehyde + 2 Fe(II)-[cytochrome c] + 2 H(+) A + ethanol = acetaldehyde + AH2 1-propanol + 2 Fe(III)-[cytochrome c] = 2 Fe(II)-[cytochrome c] + 2 H(+) + propanal Binds 1 PQQ group non-covalently per subunit (PubMed:7730276). PQQ is inserted between disulfide Cys-139-Cys-140 and the plane of Trp-282 (By similarity). Binds 2 calcium ions per subunit. One is located in the active-site cavity near PQQ and the second calcium binds at the N-terminus and contributes to the stability of the native enzyme. Enhanced by the presence of ethylamine or NH4(+) ions. Optimum pH is 9.0. Alcohol metabolism; ethanol degradation; acetate from ethanol: step 1/2. Homodimer. Induced by ethanol, and to a lesser extent, by 1-propanol and other alcohols (PubMed:7730276, PubMed:19202108). Repressed by lactate, acetate and tricarboxylic acid cycle intermediates such as citrate and succinate (PubMed:19202108). Up-regulated by exaE and agmR (PubMed:18218017, PubMed:19202108). Cells lacking this gene show a strong reduction in the growth rate on ethanol, however growth on 1-butanol or 1,2-propanediol is not influenced. Belongs to the bacterial PQQ dehydrogenase family.