The aim of this study was to determine the number of bacteria and fungi in the fermentation process and characterization of these microorganisms. There were several steps in this research including production of fermented feed, isolation of indigenous microorganisms, purification, characterization of microorganisms, species identification and test of cellulolytic activity. Results showed that eight bacteria and four fungi indigenous from the fermented feed were isolated. The species were Bacillus badius, B. subtilis, B. brevis, B. pumilus, B. cereus, Xenorhabdus luminescent, Pseudomonas stutzeri and P. diminuta. In addition, the species of fungi were Aspergillus niger, A. flavus, Mucor sp. and Cunninghamella sp. All of isolates shown the excellent cellulolytic activity. Aspergillus niger, Cunninghamella sp., B. brevis, B. cereus, and P. diminuta showed the best celulolytic activity. We recommend the use of microorganisms in the manufacture of cellulose fermentation starter component of the formula for producing ruminant feeds.

Keywords: Water Hyacinth, Cellulolytic degradation, Cellulolytic bacteria, Cellulolytic fungi, Fermented feed production