不同植物乳植杆菌联用剂对青贮中微生物群落的影响

Effects of combined Lactiplantibacillus plantarum inoculants on microbial community in silage

中文关键词:  甜高粱  玉米  布氏乳杆菌  水溶性碳水化合物  酿酒酵母属  KEGG数据库  MetaCyc数据库

英文关键词:sweet sorghum  corn  Lactobacillus buchneri  WSC  Saccharomyces  KEGG  MetaCyc

中文摘要:

      本研究旨在探究植物乳植杆菌联用不同制剂与青贮微生物群落结构及代谢功能间的互作关系。以全株甜高粱(S)和全株玉米(C)为研究对象,测定其养分含量后分别添加植物乳植杆菌(CK)、植物乳植杆菌+酿酒酵母属+纤维素酶(Ⅰ)、植物乳植杆菌+酿酒酵母属+枯草芽孢杆菌(Ⅱ)和植物乳植杆菌+布氏乳杆菌(Ⅲ),发酵45 d和90 d后抽提DNA进行16S rRNA和18S rRNA扩增测序,对其中的细菌和真菌群落结构多样性及物种丰度进行测定分析,并进行代谢功能预测。结果显示:1)甜高粱水溶性碳水化合物(WSC)含量高、淀粉含量低,利于乳酸菌(LAB)快速定植；玉米WSC含量低、淀粉含量高,利于提供长期碳源；2)随着发酵时间增加,细菌和真菌群落多样性均增加,Ⅲ中细菌群落多样性的变化幅度最低；发酵时间对甜高粱青贮细菌群落结构的影响大于联用方式,联用方式是决定玉米青贮细菌群落结构的主要因素；3)发酵45 d时细菌绝对优势菌种为厚壁菌门乳杆菌科,除C-Ⅲ外,其相对丰度在90 d时均下降,拟杆菌门和变形菌门相对丰度增加；C-Ⅲ的物种相对丰度变化与其他所有处理均有明显差异；4)子囊菌门是所有处理中的真菌绝对优势菌门,优势菌属包括哈萨克斯坦酵母属/假丝酵母属、酿酒酵母属、哈萨克斯坦酵母属和毕赤酵母属；5)甜高粱青贮中细菌的嘧啶/嘌呤代谢、糖酵解等随发酵时间下调,单独接种植物乳植杆菌时下调最显著,联用布氏乳杆菌时代谢最稳定,而真菌分解代谢激活可促进底物利用；玉米青贮中联用布氏乳杆菌时增强核酸代谢与真菌碳源分解,形成不同群落互作。综上所述,青贮中微生物群落的结构和代谢功能随底物碳源类型和发酵时间动态演变；甜高粱适合短期快速发酵,植物乳植杆菌单用即可；玉米适合长期发酵保存,联用植物乳植杆菌和布氏乳杆菌可维持其中微生物群落的长期稳定性。

英文摘要:

      This study was designed to elucidate the interaction dynamics between Lactiplantibacillus plantarum combined with various preparations and the structural composition and metabolic functions of silage microbial communities. Whole-plant sweet sorghum (S) and whole-plant corn (C) were employed as experimental materials. Lacti. plantarum alone (CK), Lacti. plantarum + Saccharomyces sp. + cellulase (Ⅰ), Lacti. plantarum + Saccharomyces sp. + Bacillus subtilis (Ⅱ), and Lacti. plantarum + Lactobacillus buchneri (Ⅲ) were added respectively. After 45 and 90 days of fermentation, DNA was extracted for 16S rRNA and 18S rRNA amplification sequencing to analyze bacterial and fungal community diversity, species abundance, and metabolic function prediction. The findings indicated that: 1)Sweet sorghum exhibited high water-soluble carbohydrate (WSC) content and low starch content, facilitating rapid colonization by lactic acid bacteria; corn featured low WSC content and high starch content, conducive to providing long-term carbon sources.2)As fermentation time increased, both bacterial and fungal community diversity increased, with Treatment III exhibiting the smallest variation range in bacterial community diversity; fermentation time had a greater impact on the bacterial community structure of sweet sorghum silage, while co-inoculation approaches were the primary determinant of the bacterial community structure in corn silage; 3) At 45 days of fermentation, Lactobacillaceae within the phylum Firmicutes emerged as the dominant bacterial species. However its relative abundance declined at 90 days (except in C-Ⅲ), accompanied by increased Bacteroidetes and Proteobacteria. C-Ⅲ exhibited distinct patterns in species relative abundance changes compared to all other treatments; 4) Ascomycota was the predominant fungal phylum across all treatments, with dominant genera including Kazachstania/Candida clade, Saccharomyces sp., Kazachstania sp., and Pichia sp.; 5) In sweet sorghum silage, bacterial pyrimidine/purine metabolism and glycolysis pathways were downregulated over time, most significantly with CK. Co-application with Lacto. buchneri resulted in the most stable metabolic profile. The activation of fungal catabolism facilitated substrate utilization. In corn silage, co-application with Lacto. buchneri enhanced nucleic acid metabolism and fungal carbon decomposition, fostering unique community interactions. In summary, the structure and metabolic function of microbial communities in silage dynamically evolve with substrate carbon source types and fermentation duration. Sweet sorghum is suitable for short-term rapid fermentation, where Lacti. plantarum alone suffices; corn is suitable for long-term fermentation preservation, and co-application of Lacti. plantarum and Lacto. buchneri can maintain long-term stability in its microbial community.