Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch Cultures

The transformation of hypoglycin A (HGA), hypoglycin B (HGB), and methylene cyclopropyl glycine (MCPrG) in ruminal fluid batch cultures was investigated, and the effect of these toxins on the batch culture microorganisms using microbial metabolites was measured. An experiment was conducted using ovi...

Full description

Saved in:
Bibliographic Details
Main Authors: Anna Maria Engel, Ahmed H. El-Khatib, Martin Bachmann, Monika Wensch-Dorendorf, Fenja Klevenhusen, Stefan Weigel, Robert Pieper, Annette Zeyner
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Toxins
Subjects:
Online Access:https://www.mdpi.com/2072-6651/17/2/46
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850078514348294144
author Anna Maria Engel
Ahmed H. El-Khatib
Martin Bachmann
Monika Wensch-Dorendorf
Fenja Klevenhusen
Stefan Weigel
Robert Pieper
Annette Zeyner
author_facet Anna Maria Engel
Ahmed H. El-Khatib
Martin Bachmann
Monika Wensch-Dorendorf
Fenja Klevenhusen
Stefan Weigel
Robert Pieper
Annette Zeyner
author_sort Anna Maria Engel
collection DOAJ
description The transformation of hypoglycin A (HGA), hypoglycin B (HGB), and methylene cyclopropyl glycine (MCPrG) in ruminal fluid batch cultures was investigated, and the effect of these toxins on the batch culture microorganisms using microbial metabolites was measured. An experiment was conducted using ovine ruminal fluid batch cultures and the ANKOM RF Gas Production System over four runs, each with an incubation period of 48 h. The fermenters contained 200 mg of (i) a substrate mixture (80% cellulose, 20% starch; CSM), (ii) CSM and 1.5 mL of a solution of pure toxins (a mixture of 500 ng/mL HGA and MCPrG each; PCM), or (iii) CSM and 100 mg sycamore maple seeds (SMS). Each fermenter contained 30 mL of inoculum (ruminal fluid and buffer, 1:2 <i>v</i>/<i>v</i>). For control, autoclaved ruminal fluid was incubated with CSM, PCM, and SMS, respectively. Samples were taken from the liquid phase of the fermenters and analyzed using liquid chromatography–tandem mass spectrometry (LC/MS-MS) for sycamore maple toxins and metabolites. Microbial activity was assessed using gas production, short chain fatty acids, and NH<sub>3</sub> concentration. Additionally, pH and redox potentials were measured. In PCM, HGA and MCPrG concentrations rapidly decreased (<i>p</i> < 0.05), and were not measurable anymore after a 24 h incubation period. In SMS, the initial concentrations were 4.7 ± 1.4 µg/mL HGA, 19.9 ± 5.41 µg/mL HGB, and 1.2 ± 0.33 µg/mL MCPrG. In SMS, HGA increased in 24 h, coincidently to a decrease in HGB concentration (<i>p</i> < 0.05). We modeled a rapid conversion of HGB to HGA, accompanied by progressive HGA transformation. The concentration of MCPrG was constant until 4 h and decreased afterwards (<i>p</i> < 0.05). In SMS incubations, HGA and MCPrG concentrations of 5.6 ± 1.5 and 0.32 ± 0.090 µg/mL remained after 48 h, respectively. The HGB to HGA conversion and transformation of HGA and MCPrG also occurred in autoclaved ruminal fluid. Gas production and microbial metabolite concentrations were higher in SMS compared to CSM and PCM (<i>p</i> < 0.05), as the seeds were used as an additional substrate by the batch culture microorganisms.
format Article
id doaj-art-a4fc87345ac14f66844e76c0cc17e1ce
institution DOAJ
issn 2072-6651
language English
publishDate 2025-01-01
publisher MDPI AG
record_format Article
series Toxins
spelling doaj-art-a4fc87345ac14f66844e76c0cc17e1ce2025-08-20T02:45:31ZengMDPI AGToxins2072-66512025-01-011724610.3390/toxins17020046Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch CulturesAnna Maria Engel0Ahmed H. El-Khatib1Martin Bachmann2Monika Wensch-Dorendorf3Fenja Klevenhusen4Stefan Weigel5Robert Pieper6Annette Zeyner7German Federal Institute for Risk Assessment, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment, 10589 Berlin, GermanyInstitute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), GermanyFaculty of Organic Agriculture, University of Kassel, 37213 Witzenhausen, GermanyGerman Federal Institute for Risk Assessment, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment, 10589 Berlin, GermanyInstitute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), GermanyThe transformation of hypoglycin A (HGA), hypoglycin B (HGB), and methylene cyclopropyl glycine (MCPrG) in ruminal fluid batch cultures was investigated, and the effect of these toxins on the batch culture microorganisms using microbial metabolites was measured. An experiment was conducted using ovine ruminal fluid batch cultures and the ANKOM RF Gas Production System over four runs, each with an incubation period of 48 h. The fermenters contained 200 mg of (i) a substrate mixture (80% cellulose, 20% starch; CSM), (ii) CSM and 1.5 mL of a solution of pure toxins (a mixture of 500 ng/mL HGA and MCPrG each; PCM), or (iii) CSM and 100 mg sycamore maple seeds (SMS). Each fermenter contained 30 mL of inoculum (ruminal fluid and buffer, 1:2 <i>v</i>/<i>v</i>). For control, autoclaved ruminal fluid was incubated with CSM, PCM, and SMS, respectively. Samples were taken from the liquid phase of the fermenters and analyzed using liquid chromatography–tandem mass spectrometry (LC/MS-MS) for sycamore maple toxins and metabolites. Microbial activity was assessed using gas production, short chain fatty acids, and NH<sub>3</sub> concentration. Additionally, pH and redox potentials were measured. In PCM, HGA and MCPrG concentrations rapidly decreased (<i>p</i> < 0.05), and were not measurable anymore after a 24 h incubation period. In SMS, the initial concentrations were 4.7 ± 1.4 µg/mL HGA, 19.9 ± 5.41 µg/mL HGB, and 1.2 ± 0.33 µg/mL MCPrG. In SMS, HGA increased in 24 h, coincidently to a decrease in HGB concentration (<i>p</i> < 0.05). We modeled a rapid conversion of HGB to HGA, accompanied by progressive HGA transformation. The concentration of MCPrG was constant until 4 h and decreased afterwards (<i>p</i> < 0.05). In SMS incubations, HGA and MCPrG concentrations of 5.6 ± 1.5 and 0.32 ± 0.090 µg/mL remained after 48 h, respectively. The HGB to HGA conversion and transformation of HGA and MCPrG also occurred in autoclaved ruminal fluid. Gas production and microbial metabolite concentrations were higher in SMS compared to CSM and PCM (<i>p</i> < 0.05), as the seeds were used as an additional substrate by the batch culture microorganisms.https://www.mdpi.com/2072-6651/17/2/46sycamore maple treesecondary plant metabolitesphytotoxinsrumen fermentationatypical myopathy
spellingShingle Anna Maria Engel
Ahmed H. El-Khatib
Martin Bachmann
Monika Wensch-Dorendorf
Fenja Klevenhusen
Stefan Weigel
Robert Pieper
Annette Zeyner
Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch Cultures
Toxins
sycamore maple tree
secondary plant metabolites
phytotoxins
rumen fermentation
atypical myopathy
title Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch Cultures
title_full Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch Cultures
title_fullStr Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch Cultures
title_full_unstemmed Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch Cultures
title_short Release of Hypoglycin A from Hypoglycin B and Decrease of Hypoglycin A and Methylene Cyclopropyl Glycine Concentrations in Ruminal Fluid Batch Cultures
title_sort release of hypoglycin a from hypoglycin b and decrease of hypoglycin a and methylene cyclopropyl glycine concentrations in ruminal fluid batch cultures
topic sycamore maple tree
secondary plant metabolites
phytotoxins
rumen fermentation
atypical myopathy
url https://www.mdpi.com/2072-6651/17/2/46
work_keys_str_mv AT annamariaengel releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures
AT ahmedhelkhatib releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures
AT martinbachmann releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures
AT monikawenschdorendorf releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures
AT fenjaklevenhusen releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures
AT stefanweigel releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures
AT robertpieper releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures
AT annettezeyner releaseofhypoglycinafromhypoglycinbanddecreaseofhypoglycinaandmethylenecyclopropylglycineconcentrationsinruminalfluidbatchcultures