Accumulation of soluble menaquinones MK-7 in honey coincides with death of Bacillus spp. present in honey
| Autor: | Katrina Brudzynski, Robert Flick |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Programmed cell death
B. amyloliquefaciens Bacillus cereus Bacillus lcsh:TX341-641 Bacillus subtilis Article Analytical Chemistry Microbiology Menaquinones B. thuringiensis Fragmentation (cell biology) biology lcsh:TP368-456 Chemistry MK-8 Vitamin K2 fungi MK-7 food and beverages Bacteria Present B. methylotrophicus biology.organism_classification B. pumilus lcsh:Food processing and manufacture B. cereus UPLC–ESI-MS/MS Honey bacterial composition Exact mass measurements Bacillus spp lcsh:Nutrition. Foods and food supply Bacteria Food Science |
| Zdroj: | Food Chemistry: X Food Chemistry: X, Vol 1, Iss, Pp-(2019) |
| ISSN: | 2590-1575 |
| Popis: | Highlights • In stored honeys, bacterial composition consists mainly of Bacillus spp. • MK-7 and MK-8 were predominant menaquinones produced by the residing bacteria. • MK-7 and MK-8 were predominant menaquinones extracted from honey. • MKs identification was based on UHPLC–ESI-MS/MS and quadrupole orbitrap. • Maximal accumulation of soluble MK-7 coincides with a massive cell death of Bacillus spp. • Bacterial cell death and lysis is a likely mechanism of the MK-7 release to honey. Long-chain menaquinones (MK) are of bacterial origin. We investigated the possibility that MKs observed in honey are also the products of bacteria present in honey. The bacterial composition of honey was analyzed using culture-dependent methods. 16S rRNA gene sequencing and MALDI-TOF showed prevalence of the members of Bacillus subtilis and Bacillus cereus groups. The dominant menaquinones in both bacteria and honey were menaquinones MK-7 and MK-8 as indicated by UHPLC–ESI-MS/MS coupled to quadrupole orbitrap. The EICs showed alignment of mass ions of MK-7 and MK-8 from culture supernatants with that of honey. The unique MS/MS fragmentation pattern indicated that fragment ions were arising from the same menaquinone present in both samples. During Bacillus growth, the accumulation of MK-7 in supernatants occurred in a stationary phase and coincided with cell death. These novel findings suggest that the soluble MKs in honey originate from shedding of cell membranes of dead vegetative cells. |
| Databáze: | OpenAIRE |
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