4种栽培模式下铁皮石斛提取物抑菌活性

Antimicrobial Activity of Extracts from Dendrobium officinale Kimura et Migo Grown Under Four Cultivation Methods

设计林下床栽、林下附生、林下悬挂和大棚床栽等4种栽培模式,比较铁皮石斛提取物抑菌活性。结果表明:林下附生铁皮石斛提取物对金黄色葡萄球菌、大肠杆菌和黏质沙雷氏菌H30的抑菌效果最好,抑菌直径分别为12.64、11.93和8.49mm,最低抑菌浓度(MIC)为15.62、31.25和250μg·mL^(-1);林下床栽的铁皮石斛提取物对铜绿假胞杆菌和黏质沙雷氏菌MG1的抑菌效果最好,抑菌直径分别为9.35和9.33mm,MIC分别为62.5和125μg·mL^(-1)。同时,林下附生的铁皮石斛提取物多糖含量为78.54%,醇溶性浸出物含量为36.01%,在各铁皮石斛中含量最高。相关性研究显示,多糖与金黄色葡萄球菌和大肠杆菌呈现显著正相关(P<0.05或P<0.01),相关系数分别为0.995和0.951。浸出物与黏质沙雷氏菌MG1呈现显著正相关(P<0.05),相关系数为0.984。可见,不同栽培模式影响到铁皮石斛的功能成分,进而也影响了抑菌效果。

Four different methods,i, e. , （A） bed planting under trees in forest, （B） intergrowth under trees in forest, （C） suspending on trees in forest, and （D） bed planting in greenhouse, were applied to cultivate Dendrobium officinale Kimura et Migo to compare the antimicrobial activity of the extracts from the plants. The results showed that the antimicrobial effect of the extract from the plants grown under （B）, as indicated by the diameter of the inhibition zones （IZ） on petri dish medium, was most significant on Staphylococcus aureus （12.64 mm dia. ）, Escherichia coli （11.93 mm dia. ）, and Serratia marcescens H30 （8. 49 mm dia. ） with the minimum inhibitory concentrations （MICs） of 15.62, 31.25, and 250 g· mL^-1, respectively. The extract from the plants grown under （A） had the best antimierobial effects shown on Pseudornonas aeruginosa （IZ of 9.35 mm in dia. ） and S. marcescens MG1 （IZ of 9.33 mm in dia. ） with MICs of 62. 5 and 125 g· mL^-1, , respectively. Among the 4 cultivation methods, （B） yielded the highest extraction rates on polysaecharides （78.54%） and ethanol soluble （36.01%） from the plants. A regression analysis on the antimicrobial activities and chemicals of the extracts indicated a positive correlation between the polysaccharide content and the inhibition on S. Aureus and E. coli with correlation coefficients of 0. 995 and 0. 951, respectively, （P〈0.05 or P〈0.01） ; while the ethanol soluble and the inhibition on S. marcescens correlated significantly with a correlation coefficient of 0. 984 at P〈0.05. Therefore, it appeared that cultivation method affected the functional components in D. officinale, and in turn, the antimicrobial activity of the plant extracts.