| 摘要: |
| [目的]研究2株鱼源乳酸菌的生物学特性,为石斑鱼高效益生菌株的筛选提供试验依据。[方法] 体外检测乳酸菌EA-1和Y4-2产乳酸及超氧化物歧化酶(SOD)的能力,以及2菌株对不同pH值、胆盐、胃蛋白酶和高温的耐受能力。[结果] 菌株EA-1和Y4-2均具有较强的产乳酸能力,培养液中的乳酸含量在96 h内随培养时间延长呈上升趋势,EA-1产乳酸速度相对较快。菌株EA-1和Y4-2均能在培养24 h后产生活性稳定的SOD,培养48 h后EA-1产生的SOD活性显著高于Y4-2(P<0。05)。菌株EA-1和Y4-2 经pH 2。5～4。5处理4 h后存活数维持在106 mL-1以上,菌株Y4-2对pH 1。5低酸环境的耐受能力强于EA-1。2菌株在1 g/L胆盐质量浓度下存活数均较高；胆盐质量浓度达到2 g/L时,EA-1和Y4-2的存活数可维持在105 mL-1以上,提示2菌株对≤2 g/L的胆盐具有一定的耐受性。经4～10 g/L的蛋白酶处理30 min后,EA-1和Y4-2的存活数均维持在106 mL-1以上。经60 ℃处理30 min后EA-1和Y4-2的存活数均维持在106 mL-1以上, Y4-2对80 ℃高温的耐受能力较EA-1强,说明EA-1和Y4-2有一定的热耐受性。[结论] EA-1和Y4-2产乳酸和SOD能力均较强,且对低pH值、高胆盐、胃蛋白酶和高温具有一定的耐受能力。 |
| 关键词: 乳酸菌 乳酸 石斑鱼 SOD 耐受 |
| DOI： |
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| 基金项目:国家自然科学基金项目（30600461）；集美大学科研基金项目（C60616） |
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| Biological characteristics of two lactic acid bacteria from orange-spotted grouper(Epinephelus coioides)larvae |
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| Abstract: |
| 【Objective】 Biological characters of 2 strains of lactic acid bacteria were studied to provide theoretic support in good probiotics strain selection for grouper. 【Method】 Lactic acid and SOD production by lactic acid bacteria strains EA-1 and Y4-2 from Orange-spotted Grouper（Epinephelus coioides）larvae,and the tolerance of the two strains to low pH,bile salt,protease and heat were studied. 【Result】 EA-1 and Y4-2 exhibited good lactic acid and SOD producing capability.Lactic acid concentration in two cultures increased as incubation proceeded,EA-1 produced lactic acid more rapidly.EA-1 and Y4-2 produced stable amount of SOD after 24 h of incubation,and the amount of SOD produced by EA-1 was significantly higher than Y4-2 after 48 h of incubation (P<0.05).The survival counts of Y4-2 and EA-1 were above 106 mL-1 after 4 h of treatment at pH 2.5-4.5.Y4-2 was more tolerant to low pH compared with EA-1.EA-1 and Y4-2 were able to survive well within 1 h incubating with 1 g/L bile salt.The survival counts of Y4-2 and EA-1 were above 105 mL-1 incubating with 2 g/L bile salt,which indicated that Y4-2 and EA-1 could tolerate bile salt concentration under 2 g/L.Pepsin had negative effect on the survival of EA-1 and Y4-2 strains, the survival counts of Y4-2 and EA-1 were above 106 mL-1 after 30 min of treatment with 4-10 g/L Pepsin.The survival counts of Y4-2 and EA-1 were above 106 mL-1 after 30 min of treatment at 60 ℃,Y4-2 was relatively more tolerant to high temperature than that of EA-1. 【Conclusion】 EA-1 and Y4-2 exhibited good lactic acid and SOD producing capability and showed good tolerance to low pH, bile salt,protease and heat. |
| Key words: lactic acid bacteria lactic acid grouper SOD tolerance |
