How is it possible for a strict aerobe to oxidatively metabolize carbohydrates without producing any acid?

I have a feeling this won't get a response, but here goes.....I did an O/F glucose (Hugh-Leifson) test on Micrococcus luteus (most likely), which is a strictly aerobic, G+ coccus (catalase +). I was expecting to see no change in the anaerobic tube and some yellow in the aerobic tube. Instead, I had a negative result in both tubes - no color change in either. The anaerobic tube is fine because I already know that I'm working with an obligate aerobe. This tells me that either a) the bacteria couldn't grow well in that medium or b) I have an asaccharolytic bacterium.



I know now that M luteus can metabolize carbohydrates aerobically without producing acid. Therefore, it seems that my test result could have been correct. If the bacteria were consuming the glucose and not producing any acid, then the medium wouldn't change color from green to yellow because the color change reaction in the O/F test is strictly based on acidity, right? Should a little bit of yellow have developed towards the top?



How can you go through aerobic respiration without producing any citric acid, pyruvic acid, etc, along the way? Or maybe they are producing acid but just not enough to cause the color reaction to happen? This is for an unknown project. I'm trying to write the report for it, but I got hung up on this issue and now I'm curious to figure it out.



Thanks for any responses.How is it possible for a strict aerobe to oxidatively metabolize carbohydrates without producing any acid?
Isn't the whole point of aerobic respiration to not produce acid, as compared to anaerobic respiration that does?How is it possible for a strict aerobe to oxidatively metabolize carbohydrates without producing any acid?
hmmm... im just a lowly undergrad so im not 100% on this. but if by chance it utilized the TCA cycle, then would produce CO2 gas, as with certain proteobacteria ? and the acids involved would remain strictly as intermediates-in relatively low amounts.



do you think that could be it?