Little is known about the bacteria that degrade cellulose. Symbiotic bacteria in Xylophaga may play a role in the degradation of sunken wood; while bacteria such as Alphaproteobacteria, Flavobacteria, Actinobacteria, Clostridia, and Bacteroidetes have been detected in wood submerged over a year.
What component of wood is degraded by bacteria that scientists are still trying to learn about?
{'text': 'cellulose', 'answer_start': 48}