The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites
Background Salting is a traditional procedure for producing pickled vegetables. Salting can be used as a pretreatment, for safe lactic acid fermentation and for salt stock preparation. This study aimed to provide valuable knowledge to improve pickle production by investigating the dynamics of microb...
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| Format: | Article |
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PeerJ Inc.
2021-04-01
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| Online Access: | https://peerj.com/articles/11123.pdf |
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| author | Kazunori Sawada Hitoshi Koyano Nozomi Yamamoto Takuji Yamada |
| author_facet | Kazunori Sawada Hitoshi Koyano Nozomi Yamamoto Takuji Yamada |
| author_sort | Kazunori Sawada |
| collection | DOAJ |
| description | Background Salting is a traditional procedure for producing pickled vegetables. Salting can be used as a pretreatment, for safe lactic acid fermentation and for salt stock preparation. This study aimed to provide valuable knowledge to improve pickle production by investigating the dynamics of microbiota and metabolites during the pretreatment and salt stock preparation processes, which have previously been overlooked. The differences in these process conditions would be expected to change the microbiota and consequently influence the content of metabolites in pickles. Methods Samples, collected from eight commercial pickle manufacturers in Japan, consisted of the initial raw materials, pickled vegetables and used brine. The microbiota were analyzed by 16S rRNA sequencing and the metabolites quantified by liquid chromatograph-mass spectrometry. Statistical analyses helped to identify any significant differences between samples from the initial raw materials, pretreatment process and salt stock preparation process groups. Results Under pretreatment conditions, aerobic and facultative anaerobic bacteria were predominant, including Vibrio, a potentially undesirable genus for pickle production. Under salt stock preparation conditions, the presence of halophilic bacteria, Halanaerobium, suggested their involvement in the increase in pyruvate derivatives such as branched-chain amino acids (BCAA). PICRUSt analysis indicated that the enhanced production of BCAA in salt stock was caused not by quantitative but by qualitative differences in the biosynthetic pathway of BCAA in the microbiota. Conclusion The differences in the microbiota between pretreatment and previously studied lactic acid fermentation processes emphasized the importance of anaerobic conditions and low pH under moderate salinity conditions for assuring safe pickle production. The results from the salt stock preparation process suggested that the Halanaerobium present may provide a key enzyme in the BCAA biosynthetic pathway which prefers NADH as a coenzyme. This feature can enhance BCAA production under anaerobic conditions where NADH is in excess. The effects shown in this study will be important for adjusting pickling conditions by changing the abundance of bacteria to improve the quality of pickled vegetables. |
| first_indexed | 2024-03-09T08:08:00Z |
| format | Article |
| id | doaj.art-cfd72e8ef585481897613d9e20f639e7 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T08:08:00Z |
| publishDate | 2021-04-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
| series | PeerJ |
| spelling | doaj.art-cfd72e8ef585481897613d9e20f639e72023-12-02T23:44:47ZengPeerJ Inc.PeerJ2167-83592021-04-019e1112310.7717/peerj.11123The effects of vegetable pickling conditions on the dynamics of microbiota and metabolitesKazunori Sawada0Hitoshi Koyano1Nozomi Yamamoto2Takuji Yamada3Innovation Division, Gurunavi, Inc., Chiyoda-ku, Tokyo, JapanSchool of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo, JapanSchool of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo, JapanSchool of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo, JapanBackground Salting is a traditional procedure for producing pickled vegetables. Salting can be used as a pretreatment, for safe lactic acid fermentation and for salt stock preparation. This study aimed to provide valuable knowledge to improve pickle production by investigating the dynamics of microbiota and metabolites during the pretreatment and salt stock preparation processes, which have previously been overlooked. The differences in these process conditions would be expected to change the microbiota and consequently influence the content of metabolites in pickles. Methods Samples, collected from eight commercial pickle manufacturers in Japan, consisted of the initial raw materials, pickled vegetables and used brine. The microbiota were analyzed by 16S rRNA sequencing and the metabolites quantified by liquid chromatograph-mass spectrometry. Statistical analyses helped to identify any significant differences between samples from the initial raw materials, pretreatment process and salt stock preparation process groups. Results Under pretreatment conditions, aerobic and facultative anaerobic bacteria were predominant, including Vibrio, a potentially undesirable genus for pickle production. Under salt stock preparation conditions, the presence of halophilic bacteria, Halanaerobium, suggested their involvement in the increase in pyruvate derivatives such as branched-chain amino acids (BCAA). PICRUSt analysis indicated that the enhanced production of BCAA in salt stock was caused not by quantitative but by qualitative differences in the biosynthetic pathway of BCAA in the microbiota. Conclusion The differences in the microbiota between pretreatment and previously studied lactic acid fermentation processes emphasized the importance of anaerobic conditions and low pH under moderate salinity conditions for assuring safe pickle production. The results from the salt stock preparation process suggested that the Halanaerobium present may provide a key enzyme in the BCAA biosynthetic pathway which prefers NADH as a coenzyme. This feature can enhance BCAA production under anaerobic conditions where NADH is in excess. The effects shown in this study will be important for adjusting pickling conditions by changing the abundance of bacteria to improve the quality of pickled vegetables.https://peerj.com/articles/11123.pdfPickle productionHalophilic bacteriaBranched-chain amino acidsSalting processFermented pickle |
| spellingShingle | Kazunori Sawada Hitoshi Koyano Nozomi Yamamoto Takuji Yamada The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites PeerJ Pickle production Halophilic bacteria Branched-chain amino acids Salting process Fermented pickle |
| title | The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites |
| title_full | The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites |
| title_fullStr | The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites |
| title_full_unstemmed | The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites |
| title_short | The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites |
| title_sort | effects of vegetable pickling conditions on the dynamics of microbiota and metabolites |
| topic | Pickle production Halophilic bacteria Branched-chain amino acids Salting process Fermented pickle |
| url | https://peerj.com/articles/11123.pdf |
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