| 摘要: |
| 【目的】对藏猪粪便中乳酸杆菌进行分离、鉴定及生物学特性研究。【方法】采集不同生长阶段藏猪（仔猪、保育猪、母猪）粪便，通过MRS选择性培养基培养、形态学观察、产酸性能测定、细菌生化鉴定及16S rDNA基因测序技术等方法从中分离、鉴定乳酸杆菌，检测藏猪源乳酸杆菌的生长曲线、耐酸耐胆盐特性、溶血活性、体外抑菌效果、益生基因，并对其进行安全性评估。【结果】从藏猪粪便中分离出48株乳酸杆菌，经16S rDNA基因测序和生物学特性分析，最终得到1株藏猪源唾液乳酸杆菌（Lactobacillus salivarius），该菌株具有较好的产酸性能，产酸量可达（0.070±0.005） mol/L；对高质量浓度胆盐和低pH具有良好的耐受能力；该菌株中检测到肠菌素P2基因（Ent P2），无溶血活性；体外抑菌结果显示，藏猪源唾液乳酸杆菌对金黄色葡萄球菌（CMCC 26003）和大肠杆菌（CMCC 44102）具有良好的抑菌效果；15 d小鼠灌胃试验结果显示，小鼠的体质量变化和脏器指数与生理盐水组无显著性差异，未观察到菌血症和细菌移位现象。【结论】筛选得到1株安全无毒副作用的藏猪源唾液乳酸杆菌，该菌具有较好的生物学特性，可作为发酵饲料和防治细菌性肠道疾病的潜在益生菌。 |
| 关键词: 藏猪 唾液乳酸杆菌 生物学特性 安全性评估 |
| DOI： |
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| 基金项目:西藏自治区厅校联合基金重点项目(XZ2019ZRG-55(Z))；西藏自治区科技厅重点研发计划项目(XZ202001ZY0039N) |
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| Isolation,identification and characterization of Lactobacillus salivarius strain from Tibetan pigs |
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KONG Qinghui,LI Jiakui,SUO Langsizhu,et al
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| Abstract: |
| 【Objective】This study isolated and identified Lactobacillus from Tibetan pig feces and studied its biological characteristics.【Method】Feces of Tibetan pig at different growth periods (piglets,nursery pigs and sows) were selected and Lactobacillus were isolated and identified by selective cultivation of MRS medium,morphological characteristics observation,acidification potential,biochemical test and 16S rDNA gene sequencing methods.The biological characteristics including growth curve,acid and bile tolerance properties,hemolytic activity,antibacterial tests in vitro,bacteriocin gene and animal toxicity were then analyzed.【Result】A total of 48 Lactobacillus strains were isolated from the Tibetan pig faeces.Then,a strain of Lactobacillus salivarius strain with high capability of acidification was obtained after 16S rDNA gene sequencing and biological characteristics analysis.Its lactic acid content was (0.070±0.005) mol/L and it exhibited high tolerance to bile and low pH.Lactobacillus salivarius strain was positive for Ent P2 (enterocin P-like bacteriocin).The result of hemolytic activity revealed that it was not involved in the lysis of erythrocytes.Lactobacillus salivarius strain had good antibacterial efficacy against E. coli (CMCC 26003) and S. aureus (CMCC 44102).The mice safety evaluation test showed that body mass and organ ratio had no significant difference after feeding with the Lactobacillus salivarius strain for 15 days and bacteremia and bacterial translocation were not observed.【Conclusion】A safe and nontoxic Lactobacillus salivarius strain was isolated from Tibetan pigs and it can be used as potential probiotic to fermented feed and control bacterial intestinal diseases. |
| Key words: Tibetan pigs Lactobacillus salivarius biological characteristics safety assessment |
