During my work with some cellulolytic bacteria isolated from an insect's gut, I noticed that they grow well in CMC solid media, but for some reason, don't grow in the liquid version of that media. I just skipped Agar during the liquid media preparation, everything else was the same. I used 37 degree celsius temperature and 180 rpm shaking as I didn't identify the bacteria yet. What is the reason for inhibiting the bacteria from growing in the liquid media? What steps can I take to overcome this problem?