王顺阳+郝燕+王洪斌+王海+张胜楠

摘要：对市售的乳酸饮品的乳酸菌进行了分离纯化，得到菌株HYWZ-6，结合16S rRNA基因序列分析，确定为瑞士乳杆菌（Lactobacillus helveticus），并以温度、NaCl、胆盐、pH及柠檬酸三钠作为影响因素，对其产VB12进行研究，并利用酶联免疫分析法对该菌在不同因素条件下培养100 h后产VB12的含量进行测定。结果表明，HYWZ-6菌株在不同条件下产VB12的差异性较大，35 ℃ VB12的含量最高，25 ℃最低，35 ℃时含量比25 ℃时高出175.2%；NaCl质量分数与VB12的含量呈反比，NaCl质量分数为1%时VB12含量最高，7%时最低，相差224.4%；胆盐质量分数为0.1%时VB12含量达到最高；pH为4时VB12含量最高，在pH为7时VB12含量最低，前者是后者的5.8倍；柠檬酸三钠质量分数为2.5%时VB12的产量最高，比最低产量高出143.2%。

关键词：瑞士乳杆菌（Lactobacillus helveticus）；分离鉴定；VB12；影响因素

中图分类号：Q939.9 文献标识码：A 文章编号：0439-8114（2017）17-3238-04

DOI：10.14088/j.cnki.issn0439-8114.2017.17.012

Isolation and Identification of a Lactobacillus helveticus and Research on the Effect Elements of VB12 Produced by It

WANG Shun-yang1， HAO Yan2， WANG Hong-bin2， WANG Hai2， ZHANG Sheng-nan2

（1.Marine College， Shandong University （Weihai）， Weihai 264209， Shandong， China；

2.Marine Resources Development Institute of Jiangsu， Lianyungang 222005， Jiangsu， China）

Abstract： A bacterial strain called HYWZ-6 was isolated and purified from lactic acid drink，being available in the market， combined with 16S rRNA sequence analysis，it was identified as Lactobacillus helveticus. The influencing factors of VB12 produced by HYWZ-6，such as temperature，NaCl，cholate，pH and trisodium citrate were studied，and the content of VB12 was measured by VB12 enzyme immunoassay after the bacterial strains had been cultivated under different circumstances for 100 hours. The results showed that the bacterial strain HYWZ-6s situation on producing VB12 under different circumstances had relatively huge differences，the content of VB12 would reach maximum at the temperature of 35 ℃，and it would reach the minimum at the temperature of 25 ℃，the discrepancy was 175.2%. The concentration of NaCl was inverse proportion to the content of VB12. When NaCl was 1%，the content of VB12 would reach maximum； when the NaCl was 7%，it would reach the minimum，the discrepancy was 224.4%. The content of VB12 would reach the maximum when cholate was 0.1%. The content of VB12 would reach the maximum when pH was 4，and it would reach the minimum when pH was 7，the former was 5.8 times as much as the latter. The output of VB12 was most when the trisodium citrate was 2.5%，the discrepancy between the highest yield and the lowest yield was 143.2%.

Key words： Lactobacillus helveticus； isolation and identificationm； VB12； influencing factor

存在于有機体内的乳酸菌具有强大的生态功效，它不仅能够加快有机体的生长速度、调节胃肠道中的正常菌群数、维持有机体内的微生态系统平衡，还能极大地改善和提高胃肠道功能；另外，还能大幅提升食物消化率和生物效价；有效降低血清胆固醇的含量，很好地控制内毒素的水平；有效抑制胃肠道内腐败细菌生长繁殖，增强机体免疫系统功能等[1，2]。与此同时，乳酸菌在工业、农业、食品和医药等与日常生活紧密相关的重要领域也有着广泛的应用前景。多数乳酸菌早已因为其特殊的益生作用越来越频繁地出现于医疗和养生领域，譬如发酵酸奶、作为微生态制剂用于胃肠道和用于制作乳酸饮品等[3-5]。……