Do Alicyclobacilli produce carbon dioxide? Do Alicyclobacilli, especially guaiacol producing ones, still produce carbon dioxide? Alicyclobacillus spp. are well known spoilage organisms in the fruit juice industry. Apparently there is no "blowing up" of the packaging (often caused by carbon dioxide production) which makes it difficult to visibly detect a potential contamination. Thus the question, do Alicyclobacilli produce carbon dioxide at all?

Alicyclobacilli are strictly aerobic and thus take up oxygen and secrete carbon dioxide, as opposed to the (facultative) anaerobic yeasts and bacilli that usually cause spoilage. So yes, alicyclobacilli produce CO2. But why doesn't the packaging swell? Compare the number of gas molecules in the simplest reactions for aerobic and anaerobic metabolism:

Aerobic metabolism: $C_6H_{12}O_6 + \underline{6 O_2} \Rightarrow \underline{6 CO_2} + 6 H_2O + 38 ATP$

Anaerobic metabolism: $C_6H_{12}O_6 \Rightarrow 2 Ethanol + \underline{2 CO_2} + 2 ATP$

Aerobes take in as much gas molecules as they excrete, while anaerobes (the ones producing ethanol at least) only make gas.