苦瓜抑菌作用的研究

Study on the antibacterial action of bitter melon

以金黄色葡萄球菌、枯草芽孢杆菌、大肠杆菌、酵母菌、青霉和黑曲霉为指示菌,采用滤纸片法研究了预处理温度、苦瓜提取物浓度对不同苦瓜品种(桂农科三号、碧珠六号、碧特111号)提取物的抑菌活性的影响,并与牛津杯法进行比较。结果表明:苦瓜预处理温度为60℃,以70%乙醇为提取溶剂,采用超声波辅助提取法获得的提取物抑菌效果最佳;苦瓜对革兰氏阳性菌的抑菌活性明显优于革兰氏阴性菌、酵母和霉菌,其中对金黄色葡萄球菌的抑制效果最强,枯草芽孢杆菌次之,对大肠杆菌和酵母抑制作用较弱,对青霉和黑曲霉无抑制作用;不同苦瓜品种中碧特111号提取物的抑菌能力最强;采用牛津杯法评价抑菌活性比滤纸片法更灵敏,稳定性更好。

Bitter melon extracts were screened for antibacterial activities against Staphylococcus aureus,Bacillus subtilis,Escherichia cofi,Yeast,Penicillium and Aspergillus niger,the disc diffusion method was used to study the effect on antimicrobial activity of pretreatment temperature,extraction solvents,extraction methods to different bitter melon varieties（Guinongke-3,Bizhu-6 and Bite-111 ）,and two evaluation methods of antibacterial activity including disc diffusion method and oxford cup method were compared. Results showed that extracts obtained under the conditions of pretreatment temperature was 60℃ ,extraction solvent chose 70% ethanol, used ultrasonic assisted extraction had the strongest antibacterial activity. The antibacterial activity of bitter melon on Gram-positive bacterium was much better than Gram-negative bacteria,Yeast and Penicillium. The inhibitory effect on StaphyLococcus aureus was the strongest,followed by Bacillus subtilis and the inhibitory effect on Escherichia coil and Yeast was weak. However,bitter melon had no effects on Penicillium and Aspergillus niger. To all the tested strains,the antibacterial activity of Bite 111 extractions was the best. The data of antibacterial activity measured by oxford cup method was more sensitive and better stability than the disc diffusion method.