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草业学报 ›› 2026, Vol. 35 ›› Issue (1): 170-178.DOI: 10.11686/cyxb2025168

• 研究论文 • 上一篇    

不同乳酸菌对象草青贮品质及四环素抗性基因的影响

尹含雪(), 黄海贝, 钟文锐, 张庆, 姚旋()   

  1. 华南农业大学林学与风景园林学院,广东 广州 510642
  • 收稿日期:2025-04-30 修回日期:2025-06-04 出版日期:2026-01-20 发布日期:2025-11-13
  • 通讯作者: 姚旋
  • 作者简介:E-mail: yaoxuan@scau.edu.cn
    尹含雪(2000-),女,江苏徐州人,在读硕士。E-mail: 15162080901@163.com
  • 基金资助:
    梅州市科技计划项目(2024A0301041)

Effects of different lactic acid bacteria on silage quality and tetracycline resistance genes in elephant grass

Han-xue YIN(), Hai-bei HUANG, Wen-rui ZHONG, Qing ZHANG, Xuan YAO()   

  1. College of Forestry and Landscape Architecture,South China Agricultural University,Guangzhou 510642,China
  • Received:2025-04-30 Revised:2025-06-04 Online:2026-01-20 Published:2025-11-13
  • Contact: Xuan YAO

摘要:

本研究旨在探讨青贮时添加不同乳酸菌对象草品质及其四环素抗性基因的影响。试验采用完全随机区组设计,以象草为青贮原料,以乳酸菌作为添加剂。共设6个处理,不添加菌液处理作为对照组(CK)。处理组为添加不同菌液,分别为植物乳杆菌处理组(菌株A,LA)、植物乳杆菌处理组(菌株B,LB)、宜春乳酪杆菌处理组(LC)、戊糖片球菌处理组(LD)和棒状腐败乳杆菌处理组(LE)。青贮30 d后开袋取样,测定营养品质、抗生素抗性基因(ARGs)。结果表明,象草青贮过程中添加不同乳酸菌,所有处理组的pH均显著低于对照组(P<0.05),同时乳酸含量均有所增加,其中LC处理组的增加尤为显著(P<0.05)。部分处理显著降低了中性洗涤纤维、酸性洗涤纤维(ADF)含量,LA、LB、LC、LD处理组的ADF含量均显著低于对照组(P<0.05)。在青贮30 d后,所有处理组的氨态氮含量均显著低于对照组(P<0.05)。试验表明,添加乳酸菌青贮后与未添加的对照组相比,四环素抗性基因(TRGs)与可移动遗传原件(MGEs)的绝对丰度显著下降(P<0.05),其中tetA、tetX、tetM、tetWtetK的绝对丰度与intl1呈极显著的正相关关系(P<0.01),且LC与LB处理组的TRGs绝对丰度显著下降(P<0.05),推断出添加宜春乳酪杆菌和植物乳杆菌有助于降低青贮象草的TRGs。综上所述,添加不同乳酸菌有助于提高青贮象草营养品质,可以减少四环素抗性基因污染。

关键词: 象草, 乳酸菌, 青贮, 四环素抗性基因

Abstract:

In this study, we investigated the effects of different lactic acid bacteria (LAB) on the fermentation quality and tetracycline resistance genes (TRGs) in elephant grass (Pennisetum purpureum) silage. Elephant grass was ensiled with six different treatments applied in a completely randomized block design. The six treatments were as follows: a control group (CK) without bacterial inoculant, and five LAB-treatment groups: a Lactiplantibacillus plantarum treatment group (strain A,LA), a L. plantarum treatment group (strain B,LB), a Lacticaseibacillus yichunensis treatment group (LC), a Pediococcus pentosaceus treatment group (LD), and the Loigolactobacillus coryniformis treatment group (LE). Following 30 days of ensiling, bags were opened and the contents were sampled to analyze the nutritional parameters of the silage and the abundance of antibiotic resistance genes (ARGs). It was found that, compared with CK, all the LAB-treatment groups exhibited significantly lower pH (P<0.05) and elevated lactic acid content. Notably, the LC group demonstrated a marked increase in lactic acid content (P<0.05). Compared with the CK, some treatment groups showed significantly decreased contents of neutral detergent fiber and acid detergent fiber (ADF). Specifically, the ADF content was significantly lower in the LA, LB, LC, and LD groups than in CK (P<0.05). The ammonia-nitrogen content was significantly lower in all LAB treatments than in CK after the 30-day ensiling period (P<0.05). Importantly, LAB supplementation significantly decreased the absolute abundance of both TRG and mobile genetic elements (MGEs), compared with CK (P<0.05). We detected strong positive correlations between the expression of the integron gene intl1 and the absolute expression levels of tetAtetXtetMtetW, and tetKP<0.01). The LC and LB groups showed the largest reductions in the absolute abundance of TRGs, compared with CK (P<0.05), indicating that L. yichunensis and L. plantarum are particularly effective in suppressing TRGs. In conclusion, specific lactic acid bacteria strains enhance the nutritional quality of elephant grass silage while mitigating contamination with TRGs.

Key words: elephant grass, lactic acid bacteria, silage, tetracycline resistance genes