Bafana Amit, Krishnamurthi Kannan, Devi Sivanesan Saravana, Chakrabarti Tapan
Environmental Biotechnology Division, National Environmental Engineering Research Institute, Nagpur 440020, India.
J Hazard Mater. 2008 Aug 30;157(1):187-93. doi: 10.1016/j.jhazmat.2007.12.085. Epub 2008 Jan 3.
In the present study, an Enterococcus gallinarum strain was isolated from effluent treatment plant of a textile industry based on its ability to decolourize C.I. Direct Black 38 (DB38), a benzidine-based azo dye. Effects of dye concentration and medium composition on dye decolourization were studied. The strain was found to decolourize DB38 even under aerobic conditions. Kinetics of DB38 decolourization was also examined, and V(max) and K(s) of decolourization were found to be higher in Luria broth (12.8 mg l(-1)h(-1) and 490.6 mg l(-1)) than in minimal medium (4.09 mg l(-1)h(-1) and 161.84 mg l(-1)). However, decolourization rate/biomass was found to be higher in minimal medium than in Luria broth, indicating greater decolourization efficiency of biomass in the former. The study also revealed biodegradation of DB38 to benzidine and its further deamination to 4-aminobiphenyl (4-ABP) by the culture. Ammonia released during this process was used as nitrogen source for growth of the culture.
在本研究中，从一家纺织工业废水处理厂分离出一株鹑鸡肠球菌，基于其对一种联苯胺基偶氮染料——直接黑38（DB38）的脱色能力。研究了染料浓度和培养基组成对染料脱色的影响。发现该菌株即使在有氧条件下也能使DB38脱色。还研究了DB38脱色动力学，发现其在Luria肉汤中的最大反应速率（V(max)）和半饱和常数（K(s)）（分别为12.8 mg l(-1)h(-1)和490.6 mg l(-1)）高于基本培养基（分别为4.09 mg l(-1)h(-1)和161.84 mg l(-1)）。然而，发现基本培养基中的脱色率/生物量高于Luria肉汤，这表明前者中生物量的脱色效率更高。该研究还揭示了培养物对DB38的生物降解作用，使其降解为联苯胺，并进一步脱氨基生成4-氨基联苯（4-ABP）。在此过程中释放的氨用作培养物生长的氮源。
