【摘要】 绿脓菌素(Pyo)的分泌是铜绿假单胞菌NY3最为显著的特征之一,前期实验观察到该菌降解烃时, Pyo分泌量常与烃的降解效率成正相关性,但其在污染物降解中的作用尚未受到关注,且机制不清楚.以共存戊二酸为高分泌Pyo的体系和试剂级Pyo标准物为基础,研究了NY3菌降解烃时,Pyo对细胞内氧化还原酶及其比酶活力和胞外电子传递速率等因素的影响作用.结果表明,戊二酸能够明显提高Pyo的分泌量,相较于无戊二酸体系提高了86.6%,且随Pyo分泌量增加,NY3菌对十六烷去除率增加了16.29%;NY3菌分泌Pyo有利于提高其胞内烷烃氧化酶的活力,在菌体生长至72h、Pyo投加量分别为200,300μL时,相较于未投加Pyo体系,烷烃氧化酶比活力分别提高了121.8%和346.5%.同时Pyo存在下将胞外电子传递速率提高了近7倍,从而增加其对十六烷的降解速率.NY3菌分泌Pyo能通过提高胞内酶活性和胞外电子传递速率而促进NY3菌降解十六烷.更多还原

【Abstract】 The secretion of pyocyanin(Pyo) is one of the most significant characteristics of Pseudomonas aeruginosa NY3. Previous experiments have observed that Pyo secretion is often positively correlated with hydrocarbon degradation efficiency, but its role in pollutant degradation has not been concerned, and the mechanism is unclear. Based on the coexistence of glutaric acid as a high-secreting Pyo system and reagent-grade Pyo standard, the effects of Pyo on intracellular redox enzyme activity, specific enzyme activity and extracellular electron transfer rate during hydrocarbon degradation by NY3 bacteria were studied. Glutaric acid could significantly increase the secretion of Pyo, which was 86.6% higher than that of non-glutaric acid system, and with the increase of Pyo secretion, the removal rate of hexadecane by NY3 bacteria increased by 16.29%. Pyo secretion by NY3 bacteria was beneficial to increase the activity of intracellular alkane oxidase. When the bacteria grew to 72 h and the dosage of Pyo was 200 L and 300 L, respectively, compared with that without Pyo system, alkane was removed by NY3 bacteria. The specific activity of hydrocarbon oxidase increased by 121.8% and 346.5% respectively. At the same time, in the presence of Pyo, the extracellular electron transfer rate was increased by nearly 7 times, which increased the degradation rate of hexadecane. Based on this, we propose that Pyo secretion by NY3 bacteria can promote the degradation of hexadecane by increasing the activity of intracellular enzymes and the rate of extracellular electron transfer.更多还原