红海榄根际土壤来源的青霉属真菌XGH2321及其抑菌活性

A Penicillium sp. XGH2321 Isolated from the Rhizospheric Soil of Rhizophora stylosa Griff and Its Antibacterial Activity

摘要:

本研究根据形态学和ITS序列分析结果, 将一株分离自海南东寨港红树林保护区红海榄根际土壤的菌株XGH2321鉴定为青霉属的一种真菌。通过对培养基中的碳源、氮源和盐度的优化, 确定了适合该真菌菌株分泌抑菌活性物质的改良查氏培养基(4%玉米浆, 0.3% NaNO3, 0.05% KCl, 0.1% K2HPO4, 0.05% MgSO4, pH 7.4, 9%盐度)。将活化后的菌株XGH2321接种到该培养基中, 按28?C、160 r/min振荡培养7 d, 获得的发酵液水萃取物对金黄色葡萄球菌、藤黄八叠球菌和枯草芽孢杆菌的生长具有明显的抑制作用(MIC为400 μg/mL), 而发酵液的乙酸乙酯萃取物对上述微生物的生长也具有一定的抑制作用(MIC为800 μg/mL); 同时, 上述2种萃取物对植物病原菌立枯丝核菌的生长也具有明显的抑制作用, MIC分别为200 μg/mL和400 μg/mL。

Abstract:

The isolate XGH2321, which isolated from the rhizospheric soil of Rhizophora stylosa Griff in Dongzhaigang Mangrove Nature Reserve in China, was identified as a fungus in the genera of Penicillium based on its morphological characteristics and internal transcribed spacer(ITS) sequence analysis. After in-oculated in the modified CzapeK-DoX medium(consisted of 4% corn steep, 0.3% NaNO3, 0.05% KCl, 0.1% K2HPO4, 0.05% MgSO4, pH 7.4, 9% salinity), and cultured under the condition of 28?C in a rotary shaker at 160 r/min for 7 days, the extracts of ethyl acetate and water-soluble from the fermentation broth showed the apparent antibacterial activities against the growth of Staphylococcus aureus, Sarcina lutea, and Bacillus subtilis with the minimum inhibitory concentration (MIC) of 800 μg/mL and 400 μg/mL, respectively. While at the same time, these two extracts could also suppress the growth of the plant pathogen, Rhizoctonia solani with MIC of 400 μg/mL and 200 μg/mL, respectively.