USDA, Agricultural Research Service, Forage-Animal Production Research Unit, Lexington, KY, USA.
J Appl Microbiol. 2018 Jan;124(1):58-66. doi: 10.1111/jam.13632. Epub 2017 Dec 18.
The objective was to determine the effect of the isoflavone biochanin A (BCA) on rumen cellulolytic bacteria and consequent fermentative activity.
When bovine microbial rumen cell suspensions (n = 3) were incubated (24 h, 39°C) with ground hay, cellulolytic bacteria proliferated, short-chain fatty acids were produced and pH declined. BCA (30 μg ml ) had no effect on the number of cellulolytic bacteria or pH, but increased acetate, propionate and total SCFA production. Addition of BCA improved total digestibility when cell suspensions (n = 3) were incubated (48 h, 39°C) with ground hay, Avicel, or filter paper. Fibrobacter succinogenes S85, Ruminococcus flavefaciens 8 and Ruminococcus albus 8 were directly inhibited by BCA. Synergistic antimicrobial activity was observed with BCA and heat killed cultures of cellulolytic bacteria, but the effects were species dependent.
These results indicate that BCA improves fibre degradation by influencing cellulolytic bacteria competition and guild composition.
BCA could serve as a feed additive to improve cellulosis when cattle are consuming high-fibre diets. Future research is needed to evaluate the effect of BCA on fibre degradation and utilization in vivo.
本研究旨在确定染料木黄酮（BCA）对瘤胃纤维分解菌及其发酵活性的影响。
当牛微生物瘤胃液悬浮液（n=3）与粉碎干草孵育（24 小时，39°C）时，纤维分解菌增殖，产生短链脂肪酸，pH 值下降。BCA（30μg/ml）对纤维分解菌数量或 pH 值没有影响，但增加了乙酸、丙酸和总 SCFA 的产生。当细胞悬浮液（n=3）与粉碎干草、Avicel 或滤纸孵育（48 小时，39°C）时，添加 BCA 可提高总消化率。BCA 直接抑制纤维分解菌 S85、Flavifactor succinogenes 8 和 Ruminococcus albus 8。BCA 与热灭活纤维分解菌培养物具有协同的抗菌活性，但作用取决于物种。
这些结果表明，BCA 通过影响纤维分解菌的竞争和菌群组成来改善纤维降解。
BCA 可作为一种饲料添加剂，在牛群摄入高纤维日粮时提高纤维素的降解。未来需要研究 BCA 对体内纤维降解和利用的影响。
