# Fermentation of increasing ratios of grain starch and straw fiber: effects on hydrogen allocation and methanogenesis throughruminal batch culture.
> 穀物デンプンと藁繊維の比率増加がルーメンバッチ培養における水素分配とメタン生成に与える影響


## Abstract

This study examined how varying the ratio of corn grain (starch source) to corn straw (fiber source) across seven levels (0:6 to 6:0) influences hydrogen partitioning and methanogenesis in ruminal batch culture. As the grain-to-straw ratio increased, dry matter degradability rose while methane and gaseous hydrogen production per unit of degraded dry matter declined. Volatile fatty acid concentrations, propionate molar proportion, and microbial protein synthesis all increased, whereas acetate proportion and estimated net metabolic hydrogen production per degraded dry matter decreased. The fraction of metabolic hydrogen directed toward methane and gaseous hydrogen production was also reduced at higher grain ratios. These findings indicate that raising the starch-to-fiber ratio shifts ruminal fermentation from acetate-dominant to propionate-dominant pathways, reduces metabolic hydrogen generation efficiency partly through enhanced microbial protein synthesis, and consequently lowers the efficiency of both methane and gaseous hydrogen production.

### Mechanism

Increasing starch proportion shifts ruminal fermentation toward propionate production and enhances microbial protein synthesis, both of which reduce net metabolic hydrogen availability and thereby decrease the efficiency of hydrogen utilization for methane and gaseous hydrogen generation.

## Bibliographic

- **Authors**: Yi S, Zhang XQ, Chen X, Zhou J, Gao C, Ma Z, et al.
- **Journal**: PeerJ
- **Year**: 2023
- **PMID**: [37077306](https://pubmed.ncbi.nlm.nih.gov/37077306/)
- **DOI**: [10.7717/peerj.15050](https://doi.org/10.7717/peerj.15050)
- **PMC**: [PMC10108854](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10108854/)
- **Study type**: in vitro study
- **Delivery route**: in vitro
- **Effect reported**: not assessed

## Delivery context

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 37077306. https://h2-papers.org/en/papers/37077306
> **Source**: PubMed PMID [37077306](https://pubmed.ncbi.nlm.nih.gov/37077306/)