自然发酵酸笋中乳酸菌的筛选鉴定及益生特性研究

Screening,identification and probiotic characteristic of lactic acid bacteria from natural fermented sour bamboo shoots

为筛选自然发酵酸笋中的益生乳酸菌,采用MRS培养基分离,经生理生化实验及16S rDNA序列分析鉴定,通过溶血实验评价安全性以及耐酸耐胆盐实验评价耐受性,并测定乳酸菌体外抗氧化性。结果表明,共分离到69株乳酸菌,隶属于2个科3个属,分别为乳杆菌属(Lactobacillus)、片球菌属(Pediococcus)、链球菌属(Streptococcus),均为γ-溶血的安全菌株,且均对0.3%胆盐具有良好耐受性,其中41株乳酸菌耐pH 2.0酸性条件,从中优选出的17株乳酸菌对人工胃肠液均有良好耐受性。4株短乳杆菌(Z1-02、ZR2-14、ZR2-12、ZR2-22)和2株消化乳杆菌(ZR1-02、ZR1-05)的1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率、2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)自由基清除率、还原能力均分别>62%、79%、0.393,其中乳杆菌Z1-02的综合抗氧化能力最强,这6株乳酸菌具备优良的益生性能和体外抗氧化活性。

The probiotic lactic acid bacteria were isolated from natural fermented sour bamboo shoots by MRS medium and identified by physiological and biochemical tests and 16S rDNA sequence analysis.The safety of the isolated strains was evaluated by hemolysis tests,the tolerance was evaluated by acid and bile salt tolerance tests,and the antioxidant activity in vitro was detected.The results showed that a total of 69 strains of lactic acid bacteria were obtained,belonging to 2 families and 3 genera,which were Lactobacillus,Pediococcus,Streptococcus,respectively.All strains were safe strains ofγ-hemolysis,with good tolerance to 0.3%bile salts.Among them,41 strains of lactic acid bacteria had good tolerance to acidic conditions of pH 2.0,and 17 screened strains of lactic acid bacteria had good tolerance to artificial gastrointestinal fluid.The 1,1-diphenyl-2-picrylhydrazyl(DPPH),2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)free radical scavenging rate and reducing power of 4 strains of Lactobacillus brevis(Z1-02,ZR2-14,ZR2-12,ZR2-22)and 2 strains of Lactobacillus alimentarius(ZR1,ZR1-05)were all higher than 62%,79%and 0.393,respectively,and the Lactobacillus Z1-02 had the strongest comprehensive antioxidant capacity,indicating that the 6 strains of lactic acid bacteria had excellent probiotic characteristic and antioxidant activity in vitro.