In search for bacterial cultures that are able to rapidly degrade cellulosic plant fibres in vitro, 77 cellulolytic
strains were isolated from Belgian and Czech soils after enrichment on flax or sisal fibres as sole
sources of carbon. The strains were characterized using fatty acid analysis, and 74 strains were grouped
into three major clusters by numerical analysis. The first major cluster contained Cellulomonas strains.
Within this cluster three sub clusters could be delineated by principal component analysis, that were recognized
by their fatty acid compositions as Cellulomonas gelida, Cellulomonas biazotea and Cellulomonas
cellulans, containing 9, 8 and 13 strains respectively. The second major cluster, with 9 strains,
was assigned to Flavobacterium johnsoniae. The 34 strains of the third cluster could not be identified by
commercial identification systems on the basis of their fatty acid profiles and API 20NE profiles. On the
basis of their phenotypic characteristics they met the description of the genus Cellvibrio, their fatty acid
profiles were similar to those of four authentic Cellvibrio mixtus strains, and the 16S rRNA genes from
four representatives showed up to 97.8% sequence similarity to 16S rDNA from Cellvibrio mixtus
ACM 2603. Three non-clustered strains were assigned to Curtobacterium flaccumfaciens, Achromobacter
piechaudii and Pseudomonas mendocina. Two strains assigned to Cellvibrio were able to degrade
several flax, broom and cotton fibres very rapidly in a standardized in vitro test, causing mass losses of
40 to 86% within 13 days of incubation, but not jute.