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 bacteria starting with the letter "F" were found in wood after it was underwater for more than a year?
{'text': 'Flavobacteria', 'answer_start': 186}