一株高效降解废水有机质耐冷菌的筛选、鉴定及特性研究

Isolation and identification of an efficient psychrotrophic bacterium and its characteristics of organic matter degradation

利用生物法进行污水处理已被国内外广泛使用,但由于温度影响微生物的生长和繁殖,使其成为生物污水处理效率的限制因子.本研究从污水处理厂活性污泥中分离出5株在低温4℃条件下生长良好的菌株,其中菌株DW1在4℃条件下,96 h时可将初始COD为800 mg·L-1的生活污水有机物去除率高达67.7%.结合菌落形态特征、生理生化特性以及16S r DNA序列分析,将菌株DW1初步鉴定为假单胞菌(Pseudomonas sp.).菌株DW1对COD负荷较高的污水处理效果较好;接种量为3%(体积分数)、p H为7.0时,菌株对污水COD去除率和DHA活性较高.在4℃和25℃条件下,菌株DW1均在96 h对污水COD去除率和DHA活性最高,分别为71.2%、11.35μg·m L·h-1(以TF计)和78.8%、15.11μg·m L-1·h-1(以TF计).

Biological method had been widely used for sewage treatment, and temperature is a limiting factor of biological sewage treatment by affecting microbial growth and reproduction. A total of 5 strains were isolated from activated sludge of sewage treatment plant and grew well at 4 ℃. The strain DW1 showed the highest COD removal rate among these 5 strains, and its efficiency was 67.7% in domestic sewage with 800 mg·L-1 initial COD at 4 ℃ after 96 h. Strain DW1 was identified as Pseudomonas sp. DW1 based on its morphological, physiological and 16S rDNA sequence. The degradation characteristics and dehydrogenase activity （DHA） of strain DW1 under different conditions were conducted. The results showed that strain DW1 had high COD removal efficiency for the sewage under high COD load. This strain possessed the highest COD removal rate and DHA activity with 3% bacterial inoculation at pH 7.0. Furthermore, the COD removal rate and DHA activity of this strain after 96 h at 4 ℃ were 71.2%、11.35 μg·mL·h-1 , and increased to 78.8% and 15.11 μg· mL-1· h-1, respectively.