Lactococcus lactis
A Lactococcus lactis, yogurt technology, applied in the directions of Streptococcus/Lactococcus, bacteria, dairy products, etc., can solve problems such as affecting the production efficiency of cell metabolic activity, and achieve the effect of simple and easy operation, obvious effect and good growth performance.
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0010] The breeding method of embodiment 1 Lactococcus lactis (CCTCC NO:M 2016235)
[0011] Lactococcus lactis NZ9000 was used as the starting strain, cultured in GM17 medium to the logarithmic growth phase, and the concentration of the bacterial solution was adjusted to 1*10 7 Unit / CFU, the supernatant was removed after the sample was centrifuged (5000rpm; 10min), washed and resuspended with 0.85% normal saline, and repeated twice. Add the same volume of normal saline to resuspend, then carry out mutagenesis treatment in a UV mutagenesis box for 40s, centrifuge, add an equal volume of GM17 medium to resuspend, and then culture at 30°C for 1.5h.
[0012] Add 1 ml of GM17 (pH 5.0) medium to 2.2 ml of 96 deep-well plates, transfer the above-mentioned post-cultivation culture solution to 96 deep-well plates with a 2% inoculation amount, and culture at 30°C for 48 hours. Investigate the growth of the mutagenized strains in the acidic medium, screen the mutant mixed strains accord...
Embodiment 2
[0013] The growth performance of embodiment 2 Lactococcus lactis (CCTCC NO:M 2016235) acid stress condition
[0014] Inject the starting strain Lactococcus lactis NZ9000 and the selected Lactococcus lactis WH103 stored in a glycerol tube at -80°C into the GM17 medium at an inoculation amount of 2%, and let it stand at 30°C Cultivate for 12h.
[0015] Transfer the activated Lactococcus lactis NZ9000 and Lactococcus lactis WH103 to GM17 (pH 4.5) medium with an inoculum amount of 2%, and culture them statically at 30°C for 48 hours. After the fermentation, measure the bacterial concentration of the fermentation broth . Under the condition of pH 4.5, the mutant strain OD 600 The value reached 0.527, which was 4.5 times higher than before breeding. The results are shown in Table 1.
[0016] Thalline growth performance under acid stress conditions in table 1
[0017] strain Lactococcus lactis NZ9000 Lactococcus lactis WH103 OD 600
Embodiment 3
[0018] Embodiment 3 acid tolerance experiment
[0019] Inject the starting strain Lactococcus lactis NZ9000 and the selected Lactococcus lactis WH103 stored in a glycerol tube at -80°C into the GM17 medium at an inoculation amount of 2%, and let it stand at 30°C Cultivate for 12h.
[0020] The activated Lactococcus lactis NZ9000 and Lactococcus lactis WH103 were respectively put into GM17 medium with an inoculation amount of 2%, and cultured statically at 30°C until the logarithmic growth phase.
[0021] Take the cells in the logarithmic growth phase, collect the cells by centrifugation at 5000rpm for 10 minutes, wash and centrifuge the cells twice with 0.85% normal saline, resuspend in an equal volume in GM17 (pH 4.0) medium, and take samples at different times of stress, and re- Centrifuge and wash the cells twice with the same normal saline, resuspend in an equal volume of normal saline, take 100 μl of the bacterial solution and spread it on a plate after appropriate dilut...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More