壳聚糖香草醛席夫碱对猕猴桃果汁污染菌的抑制作用

摘要

[ Abstract]Objective:To study the inhibitory effect of potassium sorbate,sodium benzoate,chi-tosan,and chitosan vanillin schiff-bases on contaminant bacteria in Kiwi fruit juice. Methods:The contaminant organisms were isolated from kiwi fruit juice and identified morphologically,as well with molecular biology method. DNA of contaminants were isolated with CTAB method. The 16S rDNA of bacteria and ITS gene area of fungus were amplified by PCR and sequences were analyzed for identifi-cation. The minimum inhibitory concentrations( MIC)of the four drugs were tested by trace dilution method. Results:The 4 kinds of contaminant isolated from Kiwi fruit juice included Cladosporium sp. ,Penicillium steckii,Aspergillus versicolor and Bacillus firmus. Among the 4 chemicals tested,Chi-tosan vanillin schiff-bases showed the best inhibitory effects to these contaminants. Its effect to Clados-porium sp. was as strong as those of potassium sorbate and sodium benzoate,and was stronger than that of chitosan. Its inhibitory effect to Penicillium steckii was stronger than those of potassium sorbate,so-dium benzoate,and chitosan. Its inhibitory effect to Bacillus firmus,equaled to that of sodium benzo-ate,and was stronger than those of potassium sorbate,and chitosan. Conclusion:The antibacterial effect of chitosan vanillin Schiff is stronger than those of potassium sorbate,sodium benzoate,and chi-tosan,which shows that it might has utilization potentiality.%目的：研究山梨酸钾、苯甲酸钠、壳聚糖及壳聚糖香草醛席夫碱4种药物对猕猴桃果汁污染菌的抑制作用。方法：分离及培养猕猴桃果汁中的污染菌株，采用形态学方法鉴定污染菌株，CTAB法提取污染菌DNA，采用PCR法扩增细菌的16S rDNA区和真菌的ITS区基因，扩增的目标条带进行测序分析，并用MEGA6软件构建进化树，明确猕猴桃果汁中污染菌种；采用微量液体稀释法测定山梨酸钾、苯甲酸钠、壳聚糖及壳聚糖香草醛席夫碱4种药物对猕猴桃果汁污染菌的最小抑菌浓度（ MIC）。结果：从猕猴桃果汁中分离到4株污染菌分别为枝孢菌、歧皱青霉菌、杂色曲霉菌、坚强芽胞杆菌，MIC抑菌实验结果显示壳聚糖香草醛席夫碱对4种污染菌的抑制作用最好，其中对枝孢菌的抑制作用等同于山梨酸钾和苯甲酸钠而强于壳聚糖，对歧皱青霉菌和杂色曲霉菌的抑制作用强于山梨酸钾、苯甲酸钠、壳聚糖，对坚强芽胞杆菌的抑制作用等同苯甲酸钠、强于山梨酸钾和壳聚糖。结论：壳聚糖香草醛席夫碱的抑菌效果表现最好，强于山梨酸钾、苯甲酸钠、壳聚糖，具有应用潜力。