Identify the odd one out ?
Lactobacilli, Rhizobia, Yeast, Clostridia
In the group of Lactobacilli, Rhizobia, Yeast and Clostridia, Clostridia is odd because it causes food poisoning while other microbes are beneficial. Lactobacilli make curd, Rhizobia is symbiont with legumes to fix nitrogen and yeast makes alcohol and brings about fermentation of the dough.
So, the correct answer is 'Lactobacilli, Rhizobia, Yeast, Clostridia'