Study on the Efficient Extraction and Preservation Techniques of Intracellular Antioxidant Enzymes from Lactobacillus plantarum R23

In order to obtain the intracellular antioxidant enzymes of Lactobacillus plantarum R23 with high activity, the extraction and preservation techniques of the intracellular antioxidant enzymes of Lactobacillus plantarum R23 were studied by using the protein content, the amount of bacteria and the activity of superoxide dismutase (SOD) as the main indexes. The results showed that the ultrasonic method could effectively disrupt the fungal cells of Lactobacillus plantarum R23 and maintain the ideal enzyme activity. When the ultrasonic parameters were as follows:the power of 400 W, the total working time of 20 min and the amplitude transformer of φ2 mm, the protein content was relatively high and the activity of SOD was the highest (47.06 U·g^-1). The enzyme activity could be maintained by freezing the enzyme extracting solution at 4℃ for 12 h or -20℃ for 24 h. The growth of Lactobacillus plantarum R23 corresponded with the change of protein content which was not affected by the stress of sulfur dioxide. Therefore, the protein content could be used to indicate the growth of bacterial cells for the calculation of the activity of intracellular antioxidant enzymes.