Zeru Addisu Endalew, Hassen Abubeker, Apostolides Zeno, Tjelele Julius
Department of Animal Science, University of Pretoria, Pretoria 0002, South Africa.
Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa.
Metabolites. 2022 May 31;12(6):501. doi: 10.3390/metabo12060501.
This study evaluated the relationship of secondary bioactive plant metabolite ion-features (MIFs) of Moringa oleifera accessions with antimethanogenesis to identify potential MIFs that were responsible for high and low methane inhibition from ruminants. Plant extracts from 12 Moringa accessions were evaluated at a 50 mg/kg DM feed for gas production and methane inhibition. Subsequently, the accessions were classified into low and high enteric methane inhibition groups. Four of twelve accessions (two the lowest and two the highest methane inhibitors), were used to characterize them in terms of MIFs. A total of 24 samples (12 from lower and 12 from higher methane inhibitors) were selected according to their methane inhibition potential, which ranged from 18% to 29%. Ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and untargeted metabolomics with univariate and multivariate statistical analysis with MetaboAnalyst were used in the study. Although 86 MIFs showed (p < 0.05) variation between higher and lower methane inhibition groups and lay within the detection ranges of the UPLC-MS column, only 14 were significant with the volcano plot. However, Bonferroni correction reduced the candidate MIFs to 10, and their R2-value with methane production ranged from 0.39 to 0.64. Eventually, MIFs 4.44_609.1462 and MIF 4.53_433.1112 were identified as bioactive MIFs associated with higher methane inhibition, whereas MIF 9.06_443.2317 and 15.00_487.2319 were associated with lower methane inhibition with no significant effect on in vitro organic matter digestibility of the feed. These MIFs could be used by plant breeders as potential markers to develop new M. oleifera varieties with high methane inhibition characteristics. However, further investigation on identifying the name, structure, and detailed biological activities of these bioactive metabolites needs to be carried out for future standardization, commercialization, and application as dietary methane mitigation additives.
本研究评估了辣木种质的次生生物活性植物代谢物离子特征（MIFs）与抗甲烷生成之间的关系，以确定导致反刍动物甲烷抑制率高低的潜在MIFs。以50 mg/kg干物质饲料的用量对12个辣木种质的植物提取物进行产气和甲烷抑制评估。随后，将这些种质分为低肠道甲烷抑制组和高肠道甲烷抑制组。从12个种质中选取了4个（两个甲烷抑制率最低的和两个甲烷抑制率最高的），根据MIFs对其进行表征。根据甲烷抑制潜力，共选取了24个样品（12个来自低甲烷抑制剂组，12个来自高甲烷抑制剂组），其甲烷抑制率在18%至29%之间。本研究采用超高效液相色谱-质谱联用仪（UPLC-MS）以及使用MetaboAnalyst进行单变量和多变量统计分析的非靶向代谢组学方法。尽管86种MIFs在高甲烷抑制组和低甲烷抑制组之间表现出（p < 0.05）差异，且在UPLC-MS柱的检测范围内，但通过火山图分析只有14种具有显著性。然而，经Bonferroni校正后，候选MIFs减少至10种，它们与甲烷产生的R2值在0.39至0.64之间。最终，MIF 4.44_609.1462和MIF 4.53_433.1112被鉴定为与较高甲烷抑制相关的生物活性MIFs，而MIF 9.06_443.2317和15.00_487.2319与较低甲烷抑制相关，且对饲料的体外有机物消化率无显著影响。这些MIFs可被植物育种者用作潜在标记，以培育具有高甲烷抑制特性的新辣木品种。然而，为了未来的标准化、商业化以及作为膳食甲烷减排添加剂的应用，需要进一步研究确定这些生物活性代谢物的名称、结构和详细生物活性。
