Differences in the bacterial profiles and physicochemical between natural and inoculated fermentation of vegetables from Shanxi Province
Purpose Fermented vegetables can be divided into two types, natural fermented and artificially inoculated fermented. By detecting and identifying the changes of bacterial diversity using physical and chemical indicators during natural and inoculation fermentation, we analyzed and determined the domi...
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Published in | Annals of microbiology Vol. 70; no. 1 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cham
Springer International Publishing
25.11.2020
Springer Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Purpose
Fermented vegetables can be divided into two types, natural fermented and artificially inoculated fermented. By detecting and identifying the changes of bacterial diversity using physical and chemical indicators during natural and inoculation fermentation, we analyzed and determined the dominant bacteria in the fermentation process and revealed the relationship between bacteria and volatile substances.
Methods
We used the Illumina Miseq to sequence the bacteria in fermented vegetable samples at different fermentation periods, and calculated the total number of mesophilic microorganisms and lactic acid bacteria. We used the pH and nitrite to monitor the acidification process. GC-MS was used to determine volatile flavor compounds. Finally, we analyzed the correlation between volatile flavor compounds and bacteria.
Results
Total mesophilic microorganisms and the number of lactic acid bacteria in the inoculated fermentation were higher than the natural fermentation. The bacterial diversity Shannon and Simpson indexes of the natural fermentation, higher than those of inoculated fermentation in 0~7 days, were between 55~71% and 36~45%, respectively. On the 7th day, the proportion of
Lactobacillus
in the natural fermentation and inoculated fermentation were 53.4% and 90.2%, respectively, which were significantly different.
Lactobacillus
was the dominant genus in the fermented vegetables and an important genus to promote the formation of volatile flavors.
Lactobacillus
was negatively correlated with two volatile substances (4-[2,2,6-trimethyl-7-oxabicyclo [4.1.0] hept-1-yl]-3-Buten-2-one (K4) and a-Phellandrene (X1)) and played a leading role in the fermentation process.
Conclusions
Results demonstrated that the total number of mesophilic microorganisms and lactic acid bacteria in inoculated fermentation were more than those in natural fermentation. Inoculated fermentation can shorten the fermentation cycle and reduce the content of nitrite. Lactic acid bacteria were the dominant bacteria in fermented vegetables. |
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ISSN: | 1590-4261 1869-2044 |
DOI: | 10.1186/s13213-020-01605-5 |