柑橘汁中嗜酸耐热菌的分离、鉴定以及单宁酸对其抑菌作用研究

摘要

In order to provide methods to provent Thermoacidiphilic Bacteria From juice,we study the characteristics of Thermoacidiphilic Bacteria from citrus.The Thermoacidiphilic Bacteria which was isolated from the citrus was investigated by comparison with the standard strain using Kirin-medium acidified with malic acid.Different concentrations of tannic acid were tested in Thermoacidiphilic Bacteria from citrus.The minimal inhibitory concentration was measured through the agar dilution.The results shows the two polluted bacteria isolated from citrus can grow under the temperature of 25～55 ℃ and pH of 2.4～6.0,which was corresponded with the characteristics of the Thermoacidiphilic Bacteria.Further more,the cell morphology,colony morphology,cultural characteristics,physiological characteristics and 16S rDNA tests indicated the two isolated strains of Thermoacidiphilic Bacteria have obviously similar characteristics with the standard strain.The results showed that tannins had good antibacterial activities on thermoacidiphilic bacteria,MIC of which is 1.25 mg/mL.Isolates show a high degree of similarity with the standard strains.%采用酸化的凯氏培养基对柑橘中的嗜酸耐热菌进行分离、培养纯化和鉴定并与标准菌株进行对比,再用不同浓度的单宁酸对柑橘中的嗜酸耐热菌进行抑菌试验,确定最低的抑菌浓度.结果表明,分离得到的两株可疑菌可在25～55 ℃温度范围以及2.4～6.0的pH值范围,符合嗜酸耐热菌的特点.与标准菌株在菌落形态、显微形态、生理生化特性以及16S rDNA等方面进行比较表明,2株分离菌与标准菌株有明显的相似性.抑菌试验表明,单宁酸对嗜酸耐热菌有一定的抑菌作用,单宁酸的最低抑菌浓度为1.25 mg/mL,分离菌与标准菌表现高度相似性.