1 材料与方法
1.1 蚯蚓和菌株
1.2 试验方法
1.2.1 EAMPs的提取和分离
1.2.2 EAMPs的纯化
1.2.3 EAMPs浓度的测定
1.2.4 十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)测定EAMPs分子质量
1.2.5 EAMPs抑菌活性和最小抑菌浓度(MIC)的测定
1.2.6 EAMPs的稳定性评价
1.3 数据统计分析
2 结果与分析
2.1 EAMPs的分离、纯化和鉴定
图1 EAMPs的分离、纯化和鉴定a:EAMPs的Sephadex G-100柱层析洗脱曲线;b:C组分对大肠杆菌的抑制作用;c:C组分的RP-HPLC纯化图;d:C1和C2组分对大肠杆菌的抑菌作用;e:C1和C2组分的SDS-PAGE图。 Fig.1 Isolation, purification and identification of EAMPs a: chromatography elution curve of EAMPs isolated by Sephadex G-100 column; b: inhibitory effect of C component on Escherichia coli; c: purification of C component by RP-HPLC; d: inhibitory effects of C1 and C2 components on Escherichia coli; e: electrophoretogram of C1 and C2 components by SDS-PAGE. |
2.2 EAMPs的抑菌活性和MIC
表1 EAMPs对细菌和真菌的抑制作用Table 1 Inhibitory effects of EAMPs on bacteria and fungi |
| 项目 Items | 抑菌圈直径 DIZ/mm | 抑菌环宽度 WIZ/mm | 最小抑菌浓度 MIC/(mg/L) |
|---|---|---|---|
| 革兰氏阳性菌Gram-positive bacteria | |||
| 金黄色葡萄球菌Staphylococcus aureus | 10.87±0.27a | 2.44±0.06a | 0.14±0.01d |
| 化脓性链球菌Streptococcus pyogenes | 10.64±0.21a | 2.32±0.05a | 0.14±0.01d |
| 枯草芽孢杆菌Bacillus subtilis | 8.28±0.16b | 1.14±0.03c | 0.56±0.03b |
| 革兰氏阴性菌Gram-negative bacteria | |||
| 大肠杆菌Escherichia coli | 9.53±0.18a | 1.76±0.03b | 0.56±0.02b |
| 都柏林沙门氏菌Salmonella Dublin | 9.46±0.35a | 1.73±0.05b | 0.28±0.01c |
| 弗氏志贺氏菌Shigella flexneri | 8.47±0.06b | 1.23±0.03b | 0.54±0.04b |
| 真菌Fungi | |||
| 米根霉Rhizopus oryzae | 6.93±0.10c | 0.46±0.03d | 1.12±0.05a |
| 黑曲霉Aspergillus niger | 6.53±0.18c | 0.26±0.01d | 1.12±0.07a |
| 庆大霉素Gentamicin | 10.85±0.12a | 2.43±0.02a | 0.80±0.03b |
| 磷酸盐缓冲液PBS | 0.00 | 0.00 | 0.00 |
同列数据肩标不同字母表示差异显著(P<0.05)。下表同。 | |
Values in the same column with different letter superscripts indicated significant differences (P<0.05). The same as below. |
2.3 EAMPs的热稳定性
表2 热处理温度对EAMPs抑菌活性的影响Table 2 Effects of heat treatment temperature on antimicrobial activities of EAMPs mm |
| 温度 Temperature/℃ | 抑菌圈直径 DIZ | 抑菌环宽度 WIZ |
|---|---|---|
| 25 | 9.52±0.06a | 1.76±0.02a |
| 37 | 9.52±0.04a | 1.76±0.03a |
| 50 | 9.45±0.06a | 1.73±0.05a |
| 80 | 9.20±0.07a | 1.60±0.03a |
| 100 | 8.85±0.05b | 1.43±0.06b |
2.4 贮存时间对EAMPs抑菌活性的影响
表3 贮存时间对EAMPs抑菌活性的影响Table 3 Effects of storage time on antimicrobial activities of EAMPs mm |
| 时间 Time/d | 抑菌圈直径 DIZ | 抑菌环宽度 WIZ |
|---|---|---|
| 0 | 9.68±0.10a | 1.84±0.05a |
| 90 | 9.53±0.06a | 1.77±0.03a |
| 180 | 8.82±0.03b | 1.41±0.01b |

京公网安备 11010802041926号