富硒枸杞对金黄色葡萄球菌和大肠杆菌的抑制作用

目的探讨富硒枸杞对金黄色葡萄球菌和大肠杆菌的抑制作用。方法采用琼脂平板扩散法测定富硒枸杞的抗菌活性,以金黄色葡萄球菌和大肠杆菌为实验菌种,设置1 g.mL-1、0.75 g.mL-1、0.5 g.mL-1、0.25 g.mL-1和空白组(0 g.mL-1)共5个浓度处理组。固体培养基采用肉汤培养基,每个直径7.5 cm培养皿加入12 mL培养基,制成平板备用。取培养至对数期细菌配成6×108个.mL-1菌液,涂于平板上,加不同浓度的样品溶液7μL于直径6 mm的灭菌滤纸圆片上,将已点样的滤纸圆片贴于已涂供试菌悬液的琼脂培养基上,放置20 min,再放入培养箱中37℃无光照培养24 h后测量记录抑菌环直径。结果0 g.mL-1、0.25 g.mL-1、0.5 g.mL-1、0.75 g.mL-1及1 g.mL-1富硒枸杞水煎液对金黄色葡萄球菌的抑菌环直径分别为0 mm、(21.5±0.3)mm、(22.6±0.3)mm、(24.3±0.4)mm及(27.5±0.4)mm,对大肠杆菌的抑菌环直径分别是0 mm、(20.3±0.2)mm、(22.4±0.4)mm及(26.5±0.4)mm、(31.4±0.4)mm。0.5 g.mL-1水煎液对金黄色葡萄球菌和大肠杆菌的抑菌环直径均较0.25 g.mL-1水煎液增大,但仅对大肠杆菌的抑菌环直径有统计学意义(P<0.05);0.75 g.mL-1水煎液对金黄色葡萄球菌和大肠杆菌的抑菌环直径均较0.25 g.mL-1和0.5 g.mL-1水煎液明显增大(P<0.05);1 g.mL-1水煎液对金黄色葡萄球菌和大肠杆菌的抑菌环直径均较0.25 g.mL-1、0.5 g.mL-1、0.75 g.mL-1水煎液明显增大(P<0.05)。结论富硒枸杞能明显抑制金黄色葡萄球菌和大肠杆菌活性,而且随着浓度的增加,抑菌效果逐渐增强。

Antibacterial function of seleniferous Lycium Barbarum on staphylococcus aureu and escherichia coli

Objective To study the antibacterial function of seleniferous Lycium Barbarum on staphylococcus aureu and escherichia coli. Methods The antibacterial activity of seleniferous Lycium Barbarum was determined by the agar plate diffusion method. Staphylococcus aureu and escherichia coli were used as experimental material. There were 5 concentration treatment groups：1g·mL^-1,0.75 g·mL^-1 ,0.5 g·mL^-1 ,0.25 g·mL^-1 and blank control group（0 g·mL^-1）. The solid medium was broth medium. Plates were made by adding 12 mL medium to each Petri dish whose diameter was 7.5 cm. Bacterial liquid with concentration of 6 ×10^8 cells ·mL^-1 was made using bacteria cultured to log phase. The bacterial liquid was coated to the dishes. Sample solution 7 uL with different concentrations was added to sterilized circular filter paper whose diameter was 6 mm. The circular filter paper was put on the Petri dish coated with tested bacterial liquid for 20 min,then it was put in incubator for non-light culture for 24 h. Diameters of bacteriostatic ring were measure and record after 24 h. Results Diameters of bacteriostatic ring of Staphylococcus aureu were 0 mm, （ 21.5 ± O. 3 ）mm, （ 22.6 ± 0.3 ） mm, （ 24.3 ± 0.4 ） mm, （ 27.5 ± 0.4 ） mm and of Escherichia coli were 0 mm, （20.3 ± 0.2） mm, （22.4 ± 0.4）mm, （26.5 ± 0.4） mm, （31.4 ± 0.4） mm when seleniferous Lycium Barbarum concentrations were 0 g·mL^-1 ,0.25 g ·mL^-1 ,0.5 g·mL^-1,0.75 g ·mL^-1, 1 g·mL^-1 , respectively. Both the diameters of bacteriostatie ring of staphylococcus attreu and escherichia coli were bigger using seleniferous Lycium Barbarum of the concentration 0. 5 g·mL^-1 than using one of the concentration O. 25 g·mL^-1, but statistical significance was found only in the diameter of the ring of escherichia coli（ P 〈 0.05 ）. The diameters of bacteriostatic ring of the concentration 0.75 g·mL^-1 were much bigger than the concentration 0. 25 g·mL^-1 and 0. 5 g·mL^-1（ p 〈 0. 05 ）. The diameters of bacteriostatic