一株酸性红B脱色菌的鉴定及脱色动力学

Identification of acid red B decolorization bacteria and the theoretical background of the decolorization kinetics

从城市生活污水处理厂的活性污泥中分离对酸性红B具有脱色活性的菌株,考察了不同碳源、不同氮源、葡萄糖初始质量浓度、酸性红B初始质量浓度、温度、pH值等因素对酸性红B脱色效果的影响,对菌株脱色酸性红B的条件进行了优化,研究了脱色的动力学方程。获得了对酸性红B具有良好脱色能力的菌株,对50 mg/L酸性红B模拟废水的脱色率可达96.65%,命名为Y15。通过形态学、16S rDNA序列分析鉴定得到Y15菌株为肺炎克雷伯氏菌(Klebsiella pneumoniae)。肺炎克雷伯氏菌(Klebsiella pneumoniae)对酸性红B脱色需要外加碳源,以葡萄糖最好,但不能超过2.0 g/L;适宜氮源是(NH_4)_2SO_4。在葡萄糖初始质量浓度为2 g/L、初始酸性红B质量浓度为50 mg/L、温度为35℃、初始pH值为8.0时脱色效果显著。在温度为20~40℃范围内,脱色效果符合一级动力学方程。

The paper is aimed at isolating and identifying an acid red B decolorization bacterial strain,which can be gained from the activated sludge of a municipal domestic sewage treating plant. What the paper has done is that we have systematically investigated the effects of the different carbon sources,including the nitrogen source,the initial concentration of glucose,the acid red B solutions,and the temperature,with the p H value and other factors. To achieve the above mentioned goals,we have managed to optimize the decolorization conditions for acid red B by the strain and gained the kinetics equation of acid red B decolorization. At the same time,we have also examined the optimal growing conditions of the strain through the single factor test,and heightened the strain quality with the nice decolorization capability to acid red B,known as Y15. Thus,the decolorization rate of the acid red B of the simulated sewage has been raised up to96. 65% at a concentration rate of 50 mg/L. Furthermore,we have also been successful in isolating the strain No. Y15 known as Klebsiella pneumoniae,for the purpose to analyze its morphological and phylogenetic features,by means of the 16 S r DNA sequence and the phylogenetic tree. In so doing,we have optimized the condition for the decoloriation process,which can be stated in the following way： to decolorize the acid red B,it is necessary to apply Klebsiella pneumoniae to the carbon source with the glucose being the best,though the amount added should not be over 2. 0 g/L. The best suitable nitrogen source should be chosen for（ NH_4）_2SO_4. whose decolorization effect tends to be quite efficient and remarkable with the initial concentration of glucose being 2 g/L. Therefore,the initial concentration of acid red B should be set up at 50 mg/L,at the temperature of about 35 ℃with the initial pH value of 8. 0. In the temperature range between 20-40 ℃,the decolorization effect we have worked out is in accord with the first-order kinetic equation. Thus,the above research results indicate that strain Y15 actually enjoys quite high capability for decolorizing acid red B,which can thus be entitled with an optimistic application prospect in bioremediation for the acid red B contaminated water.