Evidence map›Paper›PMID 31387603›Full record

ArticleMicrobial cell factories2019

Long-chain vitamin K2 production in Lactococcus lactis is influenced by temperature, carbon source, aeration and mode of energy metabolism.

Yue Liu, Eric O van Bennekom, Yu Zhang, Tjakko Abee, Eddy J Smid

Open access · goldAbstract read
In one paragraph

Article in Microbial cell factories, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 26 papers.

0numbers the graph read from it
0cells of the map it votes in
26citing papers in PubMed
2.7field-weighted citation impact, top 11% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

26 citing papers in PubMed, 52 citations in OpenAlex.

  1. Menaquinone biosynthesis inEngineering microbiology · 2026
    Review
  2. Article
  3. Article
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  7. Article
  8. Review
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  11. Article
  12. Review
  13. Article
  14. Article
  15. Changes in Lacto-FermentedFoods (Basel, Switzerland) · 2023
    Article
  16. Article
  17. Review
  18. Review
  19. Experimental and therapeutic medicine · 2022
    Article
  20. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors at 2 institutions in 2 countries.

Yue LiuFood Microbiology, Wageningen University and Research, PO Box 17, 6700 AA, Wageningen, The Netherlands.ORCID http://orcid.org/0000-0003-1579-6278
Eric O van BennekomBU Veterinary Drugs, RIKILT, Wageningen University and Research, Akkermaalsbos 2, 6708 WB, Wageningen, The Netherlands.
Yu ZhangFood Microbiology, Wageningen University and Research, PO Box 17, 6700 AA, Wageningen, The Netherlands.
Tjakko AbeeFood Microbiology, Wageningen University and Research, PO Box 17, 6700 AA, Wageningen, The Netherlands.
Eddy J SmidFood Microbiology, Wageningen University and Research, PO Box 17, 6700 AA, Wageningen, The Netherlands. eddy.smid@wur.nl.ORCID http://orcid.org/0000-0002-6687-5083
Wageningen University & Research · NLPeople's Bank of China · CN

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundVitamin K2 (menaquinone, MK-n) is a lipid-soluble vitamin that functions as a carboxylase co-factor for maturation of proteins involved in many vital physiological processes in humans. Notably, long-chain vitamin K2 is produced by bacteria, including some species and strains belonging to the group of lactic acid bacteria (LAB) that play important roles in food fermentation processes. This study was performed to gain insights into the natural long-chain vitamin K2 production capacity of LAB and the factors influencing vitamin K2 production during cultivation, providing a basis for biotechnological production of vitamin K2 and in situ fortification of this vitamin in food products.

resultsWe observed that six selected Lactococcus lactis strains produced MK-5 to MK-10, with MK-8 and MK-9 as the major MK variant. Significant diversities between strains were observed in terms of specific concentrations and titres of vitamin K2. L. lactis ssp. cremoris MG1363 was selected for more detailed studies of the impact of selected carbon sources tested under different growth conditions [i.e. static fermentation (oxygen absent, heme absent); aerobic fermentation (oxygen present, heme absent) and aerobic respiration (oxygen present, heme present)] on vitamin K2 production in M17 media. Aerobic fermentation with fructose as a carbon source resulted in the highest specific concentration of vitamin K2: 3.7-fold increase compared to static fermentation with glucose, whereas aerobic respiration with trehalose resulted in the highest titre: 5.2-fold increase compared to static fermentation with glucose. When the same strain was applied to quark fermentation, we consistently observed that altered carbon source (fructose) and aerobic cultivation of the pre-culture resulted in efficient vitamin K2 fortification in the quark product.

conclusionsWith this study we demonstrate that certain LAB strains can be employed for efficient production of long-chain vitamin K2. Strain selection and optimisation of growth conditions offer a viable strategy towards natural vitamin K2 enrichment of fermented foods, and to improved biotechnological vitamin K2 production processes.

Indexed as

Energy MetabolismTemperatureCarbonCulture MediaFermentationGlucoseIndustrial MicrobiologyLactococcus lactisOxygenVitamin K 2CarbonCulture MediaGlucoseOxygenVitamin K 2AerationCarbon sourceLong-chain MKsMenaquinoneNatural enrichmentRespirationVitamin K2

Identifiers

PMID31387603
PMCPMC6683496
OpenAlexW2966109166

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.