竹纤维提取物体外抗菌活性及提取方法的研究

Extraction methods and in vitro antibacterial activity of bamboo(Phyllostachys pubescens)fiber extracts

【目的】研究并明确毛竹纤维提取物的体外抗菌活性及其最佳提取方法。【方法】将毛竹纤维粉碎成粉末后,分别用水、乙醇、乙酸乙酯作为提取溶剂,按照1∶5和1∶10料液比(m∶V)分别提取1,2,4h,采用琼脂扩散法观察比较不同提取物对大肠埃希菌、金黄色葡萄球菌、枯草芽孢杆菌的抑菌作用,用倍比稀释法测定采用最佳提取方法得到的毛竹纤维提取物的最小抑菌质量浓度(MIC)和最低有效质量浓度(MBC)。【结果】毛竹纤维水提取物对3种细菌几乎无抑制作用;乙醇提取物仅对金黄色葡萄球菌有抑制作用,对其他2种细菌无明显抑制作用;乙酸乙酯提取物对3种细菌均有较强抑制作用。由此确定竹纤维提取物的最佳提取方法为:用乙酸乙酯作为提取溶剂,料液比(m∶V)为1∶5,提取时间为4h,在此条件下得到的毛竹纤维乙酸乙酯提取物对大肠埃希菌、金黄色葡萄球菌、枯草芽孢杆菌的最小抑菌质量浓度分别为0.125,0.125,0.062 5 mg/mL;最低有效质量浓度分别为0.500,0.500,0.125mg/mL。【结论】毛竹纤维在料液比为1∶5时提取4h的乙酸乙酯提取物的抑菌活性最强。

【Objective】The in vitro antibacterial activity of extracts from bamboo（Phyllostachys pubescens）fiber was investigated and the extract methods were optimized.【Method】Bamboo fiber was powdered before being extracted with agents of water,ethanol and ethyl acetate,solid-liquid ratios of 1∶5and1∶10（m∶V）,and extraction times of 1h,2hand 4h,respectively.The agar diffusion method was used to estimate the inhibition of extracts against Escherichia coli（E.coli）,Staphylococcu saureus（S.aureus）and Bacillus subtilis（B.subtilis）.The double tube dilution method was used to determine the minimum inhibitory concentration（MIC）and minimum bactericidal concentration（MBC）at the obtained optimal conditions.【Result】The water extract of bamboo fiber had little inhibition effect on three bacteria,the ethanol extract only had inhibition effect on Staphylococcu saureus,while the ethyl acetate extract had strong antibacterial activity against all 3tested bacteria.The optimal extract method was using ethyl acetate with solid-liquid ratio of 1∶5for 4h.Under optimal conditions,the MIC of bamboo fiber extract against Esche-richia coli（E.coli）,Staphylococcu saureus（S.aureus）and Bacillus subtilis were 0.125,0.125,and 0.062 5mg/mL,and the MBC were 0.500,0.500,and 0.125mg/mL,respectively.【Conclusion】The ethyl acetate extract of bamboo fiber with solid-liquid ratio of 1∶5for 4hhad the strongest inhibition effect against tested bacteria.