硫酸盐还原菌固态发酵产品酶活测定方法的建立

为建立生物质固载硫酸盐还原菌（SRB）产品酶活的检测方法，首先确定亚硫酸盐还原酶（SiR）作为SRB胞外酶表征其生物活性的可行性；其次对固态发酵产品制备粗酶液的各种条件进行探讨，研究浸泡介质、浸泡时间、超声功率、超声时间、预处理方式等单因素对酶活的影响；由正交实验确定粗酶液制备的最佳工况。实验结果表明，先浸提后超声处理的酶活值显著高于仅用超声、浸提的结果。为确保酶活值测定不受干扰，排除超声温度对结果的影响，确定实验最佳工况：2g固态发酵产品经磷酸盐缓冲液25mL、浸提60min，酶活值为1．0799U／g。生物质固载SRB酶活检测方法的建立为固态发酵产品活性评价、固态发酵条件优化、可渗透反应墙生化性能评估提供一定的理论依据。

Establishment of detection methods of enzyme activity in solid-state fermentation products of sulfate reducing bacteria

In order to establish the detection methods of biomass immobilized sulfate reducing bacteria （SRB） enzyme activity, firstly, the feasibility of sulfite reductase taken as the extracellular enzyme of SRB in characterizing the biomass was determined and then the factors for preparing the crude enzyme solution by solid-state fermentation products were explored to determine the impacts of immersion medium, soaking time, ultrasonic power, ultrasonic time and pretreatment on enzyme activity value. The optimum conditions for preparing crude enzyme solution were obtained through orthogonal experiment. The experimental results indicated that enzyme activity values treated by both lixiviate and supersonic treat- ment were significantly higher than those only treated by lixiviate and supersonic treatment. To ensure that enzyme activity value detection was not disturbed and the effect of ultrasonic temperature was eliminated, the optimum conditions deter- mined in the experiment were as follows： phosphate buffer of 25 mL, 2 g fermentation product immersion for 60 min and enzyme activity value of 1. 079 9/（U/g）. The establishment of the detection methods for biomass immobilized SRB enzyme activity may provide a theoretical basis for the assessment of immobilized SBR product activity, the optimization of solid-state fermentation conditions and the biochemical performance evaluation of PRB.