- An intron-containing glycoside hydrolase family 9 cellulase gene encodes the dominant 90 kDa component of the cellulosome of the anaerobic fungus Piromyces sp. strain E2. Steenbakkers, P.J., Ubhayasekera, W., Goossen, H.J., van Lierop, E.M., van der Drift, C., Vogels, G.D., Mowbray, S.L., Op den Camp, H.J. Biochem. J. (2002)