A bacterial strain with putative cellulosic activity was isolated, the colony produced a strong yellow halo on Congo red stained cellulose containing M9 minimal plate. Several pairs of primers for bacterial 16S gene were used to amplify the rDNA, no specific bands were identified. The bacterium grows in a broth containing M9 minimal medium supplemented with cellulose. However, when the glucose concentration in the broth was measured, there was no significant increase compared to the blank control with no bacterium inoculation. Using the Bradford assay, proteins in two-day cultures were detected although the concentration was very low. When the proteins were labeled with Cyanine-dye, and run on SDS-PAGE gel, protein bands were obvious. However, it was not so obvious on Commassie blue stained gel due to low concentration. Then proteins were precipitated using acetone, or the methanol-chloroform methods, and run on SDS-PAGE gel again. After Commassie blue staining, protein bands (or streaks) were isolated to identify protein identification following the in-gel-trypsin-digestion-mass spectrometry technique.