Résumé
An aerobic Gram positive spore-forming bacterium was isolated drom cellulose pulp mill effluent. This microorganism, identified as "Bacillus" sp. and named IS13, was able to rapdly degrade the organic chlorinateed compound 4, 5, 6-trichloroguaiacol (4, 5, 6-TCG) from a culture containing 50 mg/l, wich corresponds to about 3,0E4 times the concentration found in the organic chlorinated compound 4, 5, 6-TCG decreasing, the lack of by-products had shown by such analysis lead to verify the possibility of either adsorption of absorption of 4, 5, 6-TCG by the cells, instead of real biodegradation. There were no traces of 4, 5, 6-TCG. Plasmid isolation was attempted by using different protocols. The best results werw reached by CTAB method, but no plamid DNA was found in "Bacillus"sp. IS13. The results suggest that genes located at the bacterial chromossome might mediate the high decrease of 4, 5, 6-TCG. The importance of this work is that, in being a natural ocurring microorganism, "Bacillus" sp. IS13, can be used as inoculum in plant effluents to best organochlorinated compounds biodegradation.