柠檬酸对食用菌腐败菌的抑制作用及其作用机制  

Antibacterial effect and mechanism of citric acid on spoilage bacteria of edible mushroom

作　　者：夏飞 张处处 武子宁 曹时玲 邬培鸿 XIA Fei;ZHANG Chu-chu;WU Zi-ning;CAO Shi-ling;WU Pei-hong(School of Food Science and Engineering,Shaanxi University of Science&Technology,Xi′an 710021,China)

机构地区：[1]陕西科技大学食品科学与工程学院,陕西西安710021

出　　处：《陕西科技大学学报》2023年第2期40-45,共6页Journal of Shaanxi University of Science & Technology

基　　金：国家自然科学基金项目(31801513);陕西省科技厅重点研发计划一般项目(2021NY-120);陕西省西安市创新能力强基计划-农业技术研发项目(21NYYF0029);陕西省西安市未央区科技计划项目(202132)。

摘　　要：肠杆菌和寡养单胞菌是在采收后食用菌中数量较高的致腐细菌,可引起双孢蘑菇、杏鲍菇等食用菌的腐烂变质.柠檬酸是食品加工中常用的添加剂,对大肠杆菌、沙门氏菌等食源性病原菌有较强的抑制作用,具有无臭、无毒害、无残留等优势.本研究通过抑菌圈测定、构建时间-抑菌模型揭示柠檬酸对引起食用菌腐败的肠杆菌和寡养单胞菌的抑制效果,并进一步从细胞膜通透性、完整性和菌体形态方面揭示柠檬酸的抑菌机制.结果表明,柠檬酸对肠杆菌和寡养单胞菌的抑菌圈直径分别为1.57±0.03 cm、1.93±0.03 cm.根据Logistic方程建立柠檬酸的时间-抑菌模型,预测柠檬酸抑制肠杆菌和寡养单胞菌的最高相对生长下降比分别为36.93±1.58%和80.37±3.96%.经柠檬酸处理,肠杆菌和寡养单胞菌的菌液电导率显著增加(p≤0.001),MIC处理组12 h后分别达到5.47±0.01 ms/cm和5.01±0.01 ms/cm.此外,肠杆菌和寡养单胞菌的胞外核酸泄露量显著增加,胞外蛋白泄漏量6 h时达到最大.通过扫描电镜观察,柠檬酸处理后菌体表面粗糙,出现褶皱、弯曲,并明显发生破损.柠檬酸对肠杆菌和寡养单胞菌具有较好的抑制效果;其作用机制是通过改变细胞膜通透性和完整性,使胞内电解质外流,核酸、蛋白质等大分子外泄,从而抑制菌体生长.本研究可为采收后食用菌腐败菌无害化防治奠定基础.Enterobacter sp.and Stenotrophomonas sp.are spoilage bacteria in higher numbers in postharvest edible mushroom,which can cause decay deterioration of edible mushrooms such as Agaricus bisporus and Pleurotus eryngii.Citric acid is a common additive in food processing,which has a strong inhibitory effect on food-borne pathogens such as Escherichia coli and Salmonella and has the advantages of being odorless,non-toxic,and having no residues.In this study,the antibacterial effect of citric acid on Enterobacter sp.and Stenotrophomonas sp.causing edible mushroom spoilage was revealed through the determination of the inhibition zone and the establishment of the time-inhibition model,and the antibacterial mechanism of citric acid was further revealed from the aspects of cell membrane permeability,integrity,and thalli morphology.The results showed that the inhibition zone diameters of citric acid on Enterobacter sp.and Stenotrophomonas sp.were 1.57±0.03 cm and 1.93±0.03 cm,respectively.According to the time-inhibition model of citric acid established by the Logistic equation,the maximum relative growth decline ratios of Enterobacter sp.and Stenotrophomonas sp.were predicted to be 36.93±1.58%and 80.37±3.96%,respectively.After citric acid treatment,the conductivity of bacterial suspension increased significantly(p≤0.001)and reached 5.47±0.01 ms/cm and 5.01±0.01 ms/cm,respectively,after 12 hours in the MIC treatment group.In addition,the extracellular nucleic acid leakage increased significantly,and the extracellular protein leakage reached the maximum at 6 hours.Through scanning electron microscope observation,the thalli surface of the bacteria treated with citric acid was rough,wrinkled,bent and obviously damaged.Citric acid had a better inhibitory effect on Enterobacter sp.and Stenotrophomonas sp.;It inhibits bacterial growth by altering cell membrane permeability and integrity,allowing the efflux of intracellular electrolytes and the efflux of macromolecules such as nucleic acids and proteins.This study may provi

关 键 词：柠檬酸 腐败菌 抑菌模型 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]