Saravanan Pichiah, Pakshirajan Kannan, Saha Prabirkumar
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
J Environ Sci (China). 2008;20(12):1508-13. doi: 10.1016/s1001-0742(08)62557-7.
An acclimatized mixed microbial culture, predominantly Pseudomonas sp., was enriched from a sewage treatment plant, and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks. A 2(2) full factorial design with the two substrates at two different levels and different initial concentration ranges (low and high), was employed to carry out the biodegradation experiments. The substrates phenol and m-cresol were completely utilized within 21 h when present at low concentrations of 100 mg/L for each, and at high concentration of 600 mg/L for each, a maximum time of 187 h was observed for their removal. The biodegradation results also showed that the presence of phenol in low concentration range (100-300 mg/L) did not inhibit m-cresol biodegradation. Whereas the presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. A sum kinetics model was used to describe the variation in the substrate specific degradation rates, which gave a high coefficient of determination value (R2 > 0.98) at the low concentration range of the substrates. From the estimated interaction parameter values obtained from this model, the inhibitory effect of phenol on m-cresol degradation by the culture was found to be more pronounced compared to that of m-cresol on phenol. This study showed a good potential of the indigenous mixed culture in degrading mixed substrate of phenolics.
从一家污水处理厂富集得到一种适应环境的混合微生物培养物，主要为假单胞菌属，并在分批摇瓶培养过程中研究了其同时降解苯酚和间甲酚混合物的潜力。采用二水平二因素全因子设计，将两种底物设置为两个不同水平和不同初始浓度范围（低和高），进行生物降解实验。当苯酚和间甲酚的低浓度均为100 mg/L时，它们在21小时内被完全利用；当高浓度均为600 mg/L时，观察到其去除的最长时间为187小时。生物降解结果还表明，低浓度范围（100 - 300 mg/L）的苯酚存在不会抑制间甲酚的生物降解。而间甲酚的存在会抑制该培养物对苯酚的生物降解。此外，无论使用何种浓度，苯酚均比间甲酚优先且更早地被降解。使用一个总和动力学模型来描述底物比降解速率的变化，在底物低浓度范围内该模型具有较高的决定系数值（R2 > 0.98）。从该模型获得的估计相互作用参数值来看，发现该培养物中苯酚对间甲酚降解的抑制作用比对苯酚的抑制作用更为明显。本研究表明本地混合培养物在降解酚类混合底物方面具有良好潜力。
