添加蔗糖对苜蓿青贮碳循环中功能基因及菌群的影响  

Effects of Sucrose Addition on Functional Genes and Microbial Communities in the Carbon Cycle of Alfalfa Silage

作　　者：李荣荣 胡明 魏睿 蔡瑞 LI Rongrong;HU Ming;WEI Rui;CAI Rui(College of Environment and Life Sciences,Weinan Normal University,Weinan 714000,China;School of Environmental Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]渭南师范学院环境与生命科学学院,陕西渭南714000 [2]华中科技大学环境科学与工程学院,湖北武汉430074

出　　处：《中国草地学报》2024年第6期144-150,共7页Chinese Journal of Grassland

基　　金：国家自然科学基金项目(32302796);渭南师范学院人才项目(2022RC24)。

摘　　要：本研究采用宏基因组学技术分析不添加蔗糖(CG组)和添加蔗糖(SG组)对苜蓿青贮中碳素转化、功能基因和微生物的影响。结果表明:CG组青贮品质较差,而SG组显著提高了乳酸含量(P<0.05),改善了发酵品质。有机碳氧化和发酵是苜蓿青贮中主要的碳循环步骤,弗氏柠檬杆菌(Citrobacter freundii)、阴沟肠杆菌(Enterobacter cloacae)和大肠杆菌(Escherichia coli)是CG组中参与有机碳氧化和发酵的优势微生物,而植物乳杆菌(Lactobacillus plantarum)、阴沟肠杆菌和大肠杆菌是SG组中的优势微生物。fdoG是苜蓿青贮中有机碳氧化步骤中的主要功能基因,弗氏柠檬酸杆菌和大肠杆菌是优势宿主。pflD是发酵步骤中的主要功能基因,阴沟肠杆菌和大肠杆菌是优势宿主。因此,肠杆菌科细菌是苜蓿青贮中参与有机碳氧化和发酵步骤的主要功能微生物,而蔗糖添加剂增强了植物乳杆菌在有机碳氧化和发酵步骤中的作用。Metagenomic sequencing was employed to investigate the effects of sucrose addition(SG group)compared to no addition(CG group)on carbon transformation,functional genes,and microbial communities within alfalfa silage.The results showed that silage quality was inferior in the CG group,whereas the SG group exhibited a significant higher lactic acid content(P<0.05),indicating improved fermentation.Organic carbon oxidation and fermentation were identified as the key steps in the alfalfa silage carbon cycle.In the CG group,Citrobacter freundii,Enterobacter cloacae,and Escherichia coli were prominent contributors to both organic carbon oxidation and fermentation.In contrast,the SG group displayed a dominant role for Lactobacillus plantarum,Enterobacter cloacae,and Escherichia coli.The fdoG gene was identified as the primary functional gene for organic carbon oxidation,primarily harbored by Citrobacter freundii and Escherichia coli.The pflD gene was recognized as the main functional gene for fermentation,mainly hosted by Enterobacter cloacae and Escherichia coli.These findings suggest Enterobacteriaceae as the key functional taxa involved in organic carbon oxidation and fermentation in alfalfa silage.Notably,sucrose addition amplified the contribution of Lactobacillus plantarum to both organic carbon oxidation and fermentation processes.

关 键 词：苜蓿青贮 高水分 宏基因组 碳循环 

分 类 号：S816.53[农业科学—饲料科学]