植物乳杆菌对米酵菌酸的吸附特性研究

为了探究植物乳杆菌（Lactobacillus plantarum）X1对米酵菌酸（Bongkrekic acid,BA）的吸附特性及其影响因素。本文采用高效液相色谱（High performance liquid chromatography,HPLC）的方法测定菌体对米酵菌酸吸附率。实验考察了时间、温度、pH、菌体浓度、米酵菌酸浓度及在模拟胃肠道环境下对米酵菌酸吸附效果的影响,并对吸附过程进行热力学与动力学拟合。结果表明,菌株吸附米酵菌酸短时高效,1 h后达到饱和;温度、菌体浓度与米酵菌酸浓度升高均促进吸附进行且吸附后不易解吸。温度37℃、菌体浓度6 g·L-1与米酵菌酸浓度10 mg·L-1为最佳吸附条件,其吸附率分别为52.70%、54.12%与48.53%;酸性环境有利于米酵菌酸的吸附,pH为3时,吸附率与单位吸附量最高;在模拟胃液与肠液环境中吸附效果减弱。吸附过程符合Langmuir方程和准二级动力学方程,且为单分子层吸附。综合热力学与动力学分析可得,吸附为自发、放热的过程,并且同时存在物理吸附与化学吸附。因此,植物乳杆菌X1作为米酵菌酸吸附剂有潜在的应用潜力。

Adsorption Properties of Lactobacillus plantarum on the Bongkrekic Acid

In order to explore the adsorption characteristics and influencing factors of bongkrekic acid by Lactobacillus plantarum X1. High performance liquid chromatography was used to determine the adsorption rate of bongkrekic acid. Factors that affect the ability of the strain to remove bongkrekic acid included time, temperature, pH, bacterial concentration, bongkrekic acid concentration and simulated gastrointestinal environment. Thermodynamic and kinetic equations were used to fit the analysis results. Results showed that the strain adsorbed bongkrekic acid quickly and efficiently and the adsorption reached saturation at 1 h. The increase of temperature, bacterial concentration and bongkrekic acid concentration enhanced the adsorption and desorption was difficult after adsorption. The optimum adsorption conditions were the temperature of 37 ℃, bacterial concentration of 6 g·L?1 and bongkrekic acid concentration of 10 mg·L?1, the adsorption rates were 52.70%, 54.12% and 48.53%, respectively. Acidic environment was favorable for BA adsorption, but the adsorption effect in simulated gastrointestinal environment was reduced due to the action of protease. The adsorption capacity reached the maximum at pH3. The adsorption process conformed to Langmuir equation and Lagergren pseudo-second order equation, and it was monolayer adsorption. The thermodynamic data were analyzed and it was found that both physical adsorption and chemical adsorption existed in the adsorption process. The whole process was spontaneous and exothermic. Therefore, Lactobacillus plantarum X1 should be potential candidates as a biological detoxification agent for the remove of bongkrekic acid via their physical binding.