贵州传统酸菜中优势乳酸菌的分离鉴定及发酵特性分析

Isolation, Identification and Fermentation Characteristics Analysis of Dominant Lactic Acid Bacteria from Guizhou Traditional Sauerkraut

摘要:

为筛选适用于酸菜发酵的优良菌株，本研究从贵州传统酸菜中分离纯化出19株乳酸菌，首先根据产酸能力和生长状况进行初筛，随后基于亚硝酸盐降解能力、耐酸性、产粘性及产硫化氢性能进行复筛。结果表明，菌株RS11综合表现最优：其亚硝酸盐降解率高达98.82%；对pH值3.50的环境耐受性最佳，且不产粘、不产硫化氢。安全性评价显示，RS11无溶血活性；耐受链霉素与卡那霉素；对四环素、万古霉素和红霉素中度敏感；对氯霉素、氨苄青霉素及庆大霉素敏感。经16S rDNA鉴定为植物乳植杆菌（Lactiplantibacillus plantarum）。该菌株为同型乳酸发酵，且能够利用所有测试糖类，生长和产酸速度快：2 h进入对数生长期，12 h达到稳定期，并在12 h内将pH值降至3.98。接种发酵结果表明，与传统自然发酵相比，使用RS11可将发酵周期从7 d缩短至2 d，且发酵过程中亚硝酸盐峰值含量仅为0.62 mg·kg-1。综上，从传统酸菜发酵体系中筛选的本土植物乳植杆菌RS11兼具优异的发酵特性和安全调控功能，是适用于酸菜生产的优良菌株。

Abstract:

To screen for excellent strains suitable for sauerkraut fermentation, 19 lactic acid bacteria were isolated and purified from traditional sauerkraut in Guizhou. Firstly, a preliminary screening was carried out based on acid production capacity and growth conditions, and then a secondary screening was carried out based on the nitrite degradation ability, acid tolerance, viscosity production and hydrogen sulfide production properties. The results showed that the overall performance of the strain RS11 exhibited the best: its nitrite degradation rate was 98.8%, it exhibited optimal tolerance at pH 3.50, and produced neither viscosity nor hydrogen sulfide. Safety evaluation showed that RS11 had no hemolytic activity; showed tolerance to streptomycin and kanamycin, showed moderate sensitivity to tetracycline, vancomycin and erythromycin, and was sensitive to chloramphenicol, ampicillin and gentamicin. It was identified as Lactiplantibacillus plantarum through 16S rDNA sequencing. It underwent homolactic fermentation, utilized all tested carbohydrates, exhibited rapid growth and acid production: It entered the logarithmic growth phase within 2 h, reached the stationary phase by 12 h, and reduced the pH to 3.98 within 12 h. The inoculation and fermentation results showed that compared with traditional natural fermentation, the fermentation cycle can be shortened from 7 days to 2 days by using RS11, and the peak nitrite content during the fermentation process is only 0.62 mg·kg-1. In summary, the local Lactobacillus plantarum RS11 screened from the traditional sauerkraut fermentation system has excellent fermentation characteristics and safe regulation functions, and is an excellent strain suitable for sauerkraut production.