恩施藤茶乙醇提取物对高温煮熟鱼肉腐败菌的抑制作用研究

Inhibitory Effects of Ethanol Extract from Ampelopsis grossedentata in Enshi Against Spoilage Bacteria on Cooked Fish

以生长菌落数为评价指标,研究恩施藤茶乙醇提取物对高温煮熟鱼肉的防腐效果;采用稀释平板法分离纯化和16S rDNA测序技术鉴定导致高温煮熟鱼肉腐败变质的细菌;运用滤纸片法测试恩施藤茶乙醇提取物对腐败变质细菌的抑菌活性;通过测定恩施藤茶乙醇提取物对腐败变质细菌生长曲线、导电率及生物大分子含量的影响研究其抑菌机理。结果表明:在储藏15 d内,30 mg·mL-1恩施藤茶乙醇提取物能完全抑制高温煮熟鱼肉中细菌生长;分离、鉴定了2株导致高温煮熟鱼肉腐败变质的细菌Bacillus methylotrophicus T-10、Alcaligenes faecalis T-9;恩施藤茶乙醇提取物对这2株腐败菌具有中敏抑菌活性(抑菌圈直径:10~20 mm),其最小抑菌浓度(MIC)分别为16.0 mg·mL-1和20.0 mg·mL-1;恩施藤茶乙醇提取物通过破坏菌体细胞膜的完整性,致使生物大分子物质外溢而发挥抑菌作用。

The antiseptic effects of ethanol extract from vine tea on cooked fish were studied using the clump counts of growing bacteria as evaluation indicator.The main spoilage bacteria from cooked fish were isolated by dilution plate method and identified by 16S rDNA sequencing technology,and the antibacterial activity of ethanol extract was determined by filtering paper method.Besides,the inhibition mechanism was further investigated through measuring the influences on growth curve,conductivity and biomacromolecules contents.Results showed that the ethanol extract from vine tea could completely inhibit bacterial growth in cooked fish for 15 days with the final concentration of 30 mg·mL-1,and the two strains of bacteria were isolated and identified as Bacillus methylotrophicus T-10 and Alcaligenes faecalis T-9.The ethanol extract showed neutral-sensitive antibacterial activities on these two strains with the minimum inhibitory concentrations(MIC)of 16.0 mg·mL-1 and 20.0 mg·mL-1.Further studies proved that ethanol extract could destroy the integrity of bacterial cell membrane and causing the spilt of macromolecular substances,thereby exerting the inhibitory effects.