%0 Journal Article
%T S¨¦lection d\'un champignon filamenteux pour l\'¨¦puration des eaux us¨¦es: le ph¨¦nol comme inhibiteur mod¨¨le de discrimination entre Aspergillus niger et A. oryzae
%A L Coulibaly
%A G Gourene
%A SN Agathos
%J Sciences & Nature
%D 2008
%I 
%X Le choix d\'un microorganisme pour ¨¦purer les eaux us¨¦es est difficile, car celui-ci doit conserver ses activit¨¦s m¨¦taboliques en situation de stress. La discrimination entre Aspergillus niger et A. oryzae, a ¨¦t¨¦ effectu¨¦e en utilisant le test de respirom¨¦trie et le ph¨¦nol comme inhibiteur mod¨¨le. Ensuite, la d¨¦gradation du ph¨¦nol seul et en pr¨¦sence de glucose par A. niger a ¨¦t¨¦ conduite en milieu a¨¦robie non renouvel¨¦. A. niger d¨¦grade le ph¨¦nol et le cat¨¦chol sans adaptation pr¨¦alable ¨¤ ces substrats. Son exposition pr¨¦alable au ph¨¦nol augmente sa vitesse de respiration nette en pr¨¦sence de celui-ci et du cat¨¦chol. Par contre, son adaptation pr¨¦alable au cat¨¦chol entra ne l\'inhibition de sa respiration. Relativement ¨¤ A. oryzae, celui-ci ne respire, en pr¨¦sence du ph¨¦nol et du cat¨¦chol, que lorsqu\'il est expos¨¦ pr¨¦alablement ¨¤ ces substrats. Cependant sa vitesse de respiration nette, en pr¨¦sence du ph¨¦nol, reste inf¨¦rieure ¨¤ celle de A. niger. En pr¨¦sence du ph¨¦nol, comme substrat unique, A. niger le d¨¦grade au bout de 96 h, contre 118 h lorsqu\'il y a du glucose dans le milieu de culture. A. niger r¨¦siste au ph¨¦nol par rapport ¨¤ A. oryzae. Il peut donc ¨ºtre utilis¨¦ en ¨¦puration des eaux us¨¦es. Making the choice of a microorganism for wastewater treatment is difficult, since this organism must conserve it metabolic activity under stress condition. Discrimination between Aspergillus niger and A. oryzae was done using phenol as model inhibitory substrate and the respirometry test. Thereafter, aerobic stirred batch reactor was used to follow phenol degradation by A. niger, when it was used individually or in the presence of glucose. A. niger biomass not previously exposed to phenol and catechol degrades these compounds. However, it exposure to phenol increased the degradation of this compound and catechol. But, it exposure to catechol inhibits its respiration in the presence of this substrate and phenol comparing to its exposure to phenol. Concerning A. oryzae, this fungus degrades phenol and catechol only when it underwent a preliminary exposure. However, its respiration rates in the presence of phenol and catechol are inferior to A. niger biomass adapted to phenol. A. niger degraded phenol within 96 h when it was the unique substrate, and this was accomplished after 118 h in the presence of glucose. In addition, this fungus supports phenol stress in the growth medium than A. oryzae. Consequently, it cans be used to treat wastewaters.
%U http://www.ajol.info/index.php/scinat/article/view/42157