A. KARUNYA, SWETHA SUNKAR, S. ANURADHA JABASINGH AND C. VALLI NACHIYAR
Abstract
Four different bacterial strains have been isolated from dye containing effluent and are used for the construction of an aerobic consortium CN-1 along with Pseudomonas aeruginosa CLRI BL22 obtained from CLRI. These bacteria were identified as Citrobacter freundii (2 strains), Moraxella osloensis and Pseudomonas aeruginosa using 16S rRNA analysis. The organisms constituting the bacterial consortium CN-1 have started to degrade AB 113 in their middle lag phase. They exhibited difference only in the rate in which they carry out the dye degradation. The consortium CN-1 showed gradual increase in the rate of degradation which started in the middle lag phase and reached a maximum by 10h. With respect to growth the consortium showed an extended log phase before it reached its stationery phase by 24h with a with the first order rate constant k1 value of 0.152 h-1 was carrying out the degradation at the faster rate followed by Citrobacter freudii (both strains) and Moraxella osloensis. Screening for medium components using Plackett Burman Screening Design indicated dye concentration having larger effect followed by temperature and ammonium nitrate concentration. It can be seen with low concentration of dye and low concentration of glucose, dye decolorization by the consortium was predominating, provided temperature and ammonium nitrate were held at high concentration and pH maintained at 9.