Benzoic acid can be degraded by microbial fermentation. This process involves a series of microorganisms with enzyme activity, including bacteria, fungi and yeast.

Benzoic acid often undergoes decarboxylation in the process of producing benzaldehyde by microbial fermentation. This reaction requires the participation of benzoic acid decarboxylase.

Benzaldehyde will be further reduced to phenylethanol or oxidized to phenylacetic acid, both of which require the participation of enzymes.

The whole degradation process needs the synergistic effect of many microorganisms, including some anaerobic bacteria that can decompose complex organic matter and some aerobic bacteria that can metabolize organic matter.

Generally speaking, the process of degrading benzoic acid by microbial fermentation is complicated, involving many microorganisms and enzymes. Different microorganisms and environmental conditions will affect the efficiency and approach of degradation process, which needs further research and optimization.